Original Posted By: "gbowen(at)ptialaska.net"
Subject: Pietenpol-List: Fiberglass ConstructionIn a message dated 12/23/04 1:00:37 PM Central Standard Time, N321TX(at)wmconnect.com writes:>Sterling, Are you using the fuel tank mould that I loaned you ? If so, please use enough release agent, so as not to destroy it !! There is a couple of other folks that will need it. It's a really good mould (capacity - 10.7 gal.), andwe can pass it around to others, when you are done with it. (It is for the nose cowling fuel tank for plans dimension short fuselage.) I designed it so the bottom of the tank slopes forward, when the tail is on the ground, so any water in the fuel finds it's way to the outlet. There is no place where a pocket of water will collect. I might need it again, too, if I ever get any alcohol in my fuel !! Here is the way I built both my tanks, and J3 type nose bowl: I used Polyester Resin (for auto body repair) on both tanks. It's cheaper than Epoxy, and is a lower viscosity which aids in wetting out the fabric.However, if I build another tank, I will use the West System Epoxy Resin 105, with the 206 hardener. If you go this route, it is very convenient to buy thepumps that go with the cans, which dispenses the material at the proper ratio. Never handle any cloth with your bare hands, or touch any area where you are going to do an additional lay-up, or skin oil will prevent the resin from saturating the cloth in that area. You have to be FAST if you use the Polyester Resin, because after you put the hardener in...it Kicks in only about 5 to 7 minutes, depending on how many drops you put in. West System has a lot longer pot life (work time). Haveall the fabric cut, pre-fit, and stacked in the order they lay. I can't say enough about preparation, before you add the hardener. You can lengthen the working time some, by using a few drops less than recommended, but once it starts to jell, forget about proceeding any further. The challenge of doing composite work, is to get 100% saturation, using as little resin as possible, withno fabric separation. The way we achieve this at work, is 'Vacuum Bagging'. One of the faults of the Polyester Resin, is that it is NOT alcohol resistant. So far, I haven't had any problem. Fiberglass Cloth: I have a source here in Wichita, where I purchase the cloth, in all sizes. It ain't cheap !! Seems like I had over $35 or $40 bucks for the clothin the nose tank and nose bowl. I used two different weigh fabric - Light weight, and Medium weight.The first layer down, I used light weight. Then two layers of medium weight, then the last layer down in the Mould I used another layer of light weight. The difficult part is to get the cloth to stay down in the corners. It alwayswants to spring back out of the inside corners, no matter how many times you poke it back in. Light weigh cloth stays down in the corners much easier, because the cloth is thinner, and bends easier. This is the reason I used cornerpieces in the mould, so the fabric only has to form to 45, instead of 90. After the resin cures, and you pop the bottom and top out of the mould, you need to carefully sand the edges, so you get a nice tight fit, preferably a 45miter fit (that's what I did) then glue them together with the resin you've been using. After they are glued together, put 3 layers around the entire corner edge, stepping out from 2" for the first layer down, up to about 4" forthe last layer down. You always have to sand the shinny off, before adding any additional layers. After complete, leak test with a balloon, like Tony Bengalisrecommends. Then you should calibrate it at the gas station. Set the tank in the static laden position (the angle it will be at when the tail is on the ground), and add one gallon of fuel at a time, dip your 'Calibrated Dip Stick'in, and mark each gallon increment. The distance between these marks vary, because of the shape of the tank. I didn't have any leaks in either of the fueltanks I built. I built the Smoke Tank with just two layers of fiberglass, moulded around cereal box the right dimension, but used the West System Epoxy. It seemed like the cloth was wetted out good, but it had two places where the baby oil seeped through, and dripped about one drip every 6 minutes. I fixed them by cleaning first with Brake Clean, then sanding the area, then some more Brake Clean(with clean cloth and no finger prints), then used 5 minute epoxy, and two layers of cloth.Chuck GantzerNX770CGMerry Christmas To All !!________________________________________________________________________________
Pietenpol-List: Fiberglass Construction
Pietenpol-List: Fiberglass Construction
Original Posted By: alexms1(at)comcast.net
Subject: Pietenpol-List: Fiberglass ConstructionIn a message dated 12/23/04 1:00:37 PM Central Standard Time, N321TX(at)wmconnect.com writes:>Sterling, Are you using the fuel tank mould that I loaned you ? If so, pleaseuse enough release agent, so as not to destroy it !! There is a couple ofother folks that will need it. It's a really good mould (capacity - 10.7 gal.),and we can pass it around to others, when you are done with it. (It is for the nose cowling fuel tank for plans dimension short fuselage.) I designed itso the bottom of the tank slopes forward, when the tail is on the ground, soany water in the fuel finds it's way to the outlet. There is no place where a pocket of water will collect. I might need it again, too, if I ever getany alcohol in my fuel !! Here is the way I built both my tanks, and J3 type nosebowl: I used Polyester Resin (for auto body repair) on both tanks. It's cheaper than Epoxy, and is a lower viscosity which aids in wetting out thefabric. However, if I build another tank, I will use the West System Epoxy Resin105, with the 206 hardener. If you go this route, it is very convenient to buythe pumps that go with the cans, which dispenses the material at the properratio. Never handle any cloth with your bare hands, or touch any area whereyou are going to do an additional lay-up, or skin oil will prevent the resinfrom saturating the cloth in that area. You have to be FAST if you use the Polyester Resin, because after youput the hardener in...it Kicks in only about 5 to 7 minutes, depending on how many drops you put in. West System has a lot longer pot life (work time). Have all the fabric cut, pre-fit, and stacked in the order they lay. I can'tsay enough about preparation, before you add the hardener. You can lengthenthe working time some, by using a few drops less than recommended, but once it starts to jell, forget about proceeding any further. The challenge ofdoing composite work, is to get 100% saturation, using as little resin aspossible, with no fabric separation. The way we achieve this at work, is 'VacuumBagging'. One of the faults of the Polyester Resin, is that it is NOT alcohol resistant. So far, I haven't had any problem. Fiberglass Cloth: I have a source here in Wichita, where I purchase the cloth, in all sizes. It ain't cheap !! Seems like I had over $35 or $40 bucks for thecloth in the nose tank and nose bowl. I used two different weigh fabric - Light weight, and Medium weight.The first layer down, I used light weight. Then two layers of mediumweight, then the last layer down in the Mould I used another layer of light weight.The difficult part is to get the cloth to stay down in the corners. Italways wants to spring back out of the inside corners, no matter how many timesyou poke it back in. Light weigh cloth stays down in the corners much easier, because the cloth is thinner, and bends easier. This is the reason I usedcorner pieces in the mould, so the fabric only has to form to 45, instead of 90.After the resin cures, and you pop the bottom and top out of the mould, you need to carefully sand the edges, so you get a nice tight fit, preferably a45 miter fit (that's what I did) then glue them together with the resin you've been using. After they are glued together, put 3 layers around the entire corner edge, stepping out from 2" for the first layer down, up to about 4"for the last layer down. You always have to sand the shinny off, before adding any additional layers. After complete, leak test with a balloon, like TonyBengalis recommends. Then you should calibrate it at the gas station. Set the tank in the static laden position (the angle it will be at when the tail is onthe ground), and add one gallon of fuel at a time, dip your 'Calibrated DipStick' in, and mark each gallon increment. The distance between these marks vary, because of the shape of the tank. I didn't have any leaks in either of thefuel tanks I built. I built the Smoke Tank with just two layers of fiberglass, mouldedaround cereal box the right dimension, but used the West System Epoxy. It seemed like the cloth was wetted out good, but it had two places where the babyoil seeped through, and dripped about one drip every 6 minutes. I fixed themby cleaning first with Brake Clean, then sanding the area, then some moreBrake Clean (with clean cloth and no finger prints), then used 5 minute epoxy, and two layers of cloth.Chuck GantzerNX770CGMerry Christmas To All !!________________________________________________________________________________
Subject: Pietenpol-List: Fiberglass ConstructionIn a message dated 12/23/04 1:00:37 PM Central Standard Time, N321TX(at)wmconnect.com writes:>Sterling, Are you using the fuel tank mould that I loaned you ? If so, pleaseuse enough release agent, so as not to destroy it !! There is a couple ofother folks that will need it. It's a really good mould (capacity - 10.7 gal.),and we can pass it around to others, when you are done with it. (It is for the nose cowling fuel tank for plans dimension short fuselage.) I designed itso the bottom of the tank slopes forward, when the tail is on the ground, soany water in the fuel finds it's way to the outlet. There is no place where a pocket of water will collect. I might need it again, too, if I ever getany alcohol in my fuel !! Here is the way I built both my tanks, and J3 type nosebowl: I used Polyester Resin (for auto body repair) on both tanks. It's cheaper than Epoxy, and is a lower viscosity which aids in wetting out thefabric. However, if I build another tank, I will use the West System Epoxy Resin105, with the 206 hardener. If you go this route, it is very convenient to buythe pumps that go with the cans, which dispenses the material at the properratio. Never handle any cloth with your bare hands, or touch any area whereyou are going to do an additional lay-up, or skin oil will prevent the resinfrom saturating the cloth in that area. You have to be FAST if you use the Polyester Resin, because after youput the hardener in...it Kicks in only about 5 to 7 minutes, depending on how many drops you put in. West System has a lot longer pot life (work time). Have all the fabric cut, pre-fit, and stacked in the order they lay. I can'tsay enough about preparation, before you add the hardener. You can lengthenthe working time some, by using a few drops less than recommended, but once it starts to jell, forget about proceeding any further. The challenge ofdoing composite work, is to get 100% saturation, using as little resin aspossible, with no fabric separation. The way we achieve this at work, is 'VacuumBagging'. One of the faults of the Polyester Resin, is that it is NOT alcohol resistant. So far, I haven't had any problem. Fiberglass Cloth: I have a source here in Wichita, where I purchase the cloth, in all sizes. It ain't cheap !! Seems like I had over $35 or $40 bucks for thecloth in the nose tank and nose bowl. I used two different weigh fabric - Light weight, and Medium weight.The first layer down, I used light weight. Then two layers of mediumweight, then the last layer down in the Mould I used another layer of light weight.The difficult part is to get the cloth to stay down in the corners. Italways wants to spring back out of the inside corners, no matter how many timesyou poke it back in. Light weigh cloth stays down in the corners much easier, because the cloth is thinner, and bends easier. This is the reason I usedcorner pieces in the mould, so the fabric only has to form to 45, instead of 90.After the resin cures, and you pop the bottom and top out of the mould, you need to carefully sand the edges, so you get a nice tight fit, preferably a45 miter fit (that's what I did) then glue them together with the resin you've been using. After they are glued together, put 3 layers around the entire corner edge, stepping out from 2" for the first layer down, up to about 4"for the last layer down. You always have to sand the shinny off, before adding any additional layers. After complete, leak test with a balloon, like TonyBengalis recommends. Then you should calibrate it at the gas station. Set the tank in the static laden position (the angle it will be at when the tail is onthe ground), and add one gallon of fuel at a time, dip your 'Calibrated DipStick' in, and mark each gallon increment. The distance between these marks vary, because of the shape of the tank. I didn't have any leaks in either of thefuel tanks I built. I built the Smoke Tank with just two layers of fiberglass, mouldedaround cereal box the right dimension, but used the West System Epoxy. It seemed like the cloth was wetted out good, but it had two places where the babyoil seeped through, and dripped about one drip every 6 minutes. I fixed themby cleaning first with Brake Clean, then sanding the area, then some moreBrake Clean (with clean cloth and no finger prints), then used 5 minute epoxy, and two layers of cloth.Chuck GantzerNX770CGMerry Christmas To All !!________________________________________________________________________________
RE: Pietenpol-List: Fiberglass Construction
Original Posted By: Rcaprd(at)aol.com
As a polymer chemist I highly recommend to anyone considering usingpolyester resin for construction of a fiberglass fuel tank to make a smalltest. Make a 2" by 4" test laminate of polyester and fiberglass. Put intoa quart jar of AVGAS and MOGAS for about 1 month. You could weigh beforeand after if you've got an accurate scale, but I think you'll discover thediscoloration of the AVGAS and MOGAS plus the somewhat slimy feel of yourtest coupon will change your mind about the chemical resistance ofpolyester resins.GordonOriginal Message:-----------------
As a polymer chemist I highly recommend to anyone considering usingpolyester resin for construction of a fiberglass fuel tank to make a smalltest. Make a 2" by 4" test laminate of polyester and fiberglass. Put intoa quart jar of AVGAS and MOGAS for about 1 month. You could weigh beforeand after if you've got an accurate scale, but I think you'll discover thediscoloration of the AVGAS and MOGAS plus the somewhat slimy feel of yourtest coupon will change your mind about the chemical resistance ofpolyester resins.GordonOriginal Message:-----------------
RE: Pietenpol-List: Fiberglass Construction
Original Posted By:> Rcaprd(at)aol.com
Gordon,I take it you are strongly recommending epoxy resin for the fiberglass tank, right?I have never been a fan of polyester resin compared to epoxy. Alex Sloan-------------- Original message -------------- > > > As a polymer chemist I highly recommend to anyone considering using > polyester resin for construction of a fiberglass fuel tank to make a small > test. Make a 2" by 4" test laminate of polyester and fiberglass. Put into > a quart jar of AVGAS and MOGAS for about 1 month. You could weigh before > and after if you've got an accurate scale, but I think you'll discover the > discoloration of the AVGAS and MOGAS plus the somewhat slimy feel of your > test coupon will change your mind about the chemical resistance of > polyester resins. > Gordon > > Original Message: > -----------------
Gordon,I take it you are strongly recommending epoxy resin for the fiberglass tank, right?I have never been a fan of polyester resin compared to epoxy. Alex Sloan-------------- Original message -------------- > > > As a polymer chemist I highly recommend to anyone considering using > polyester resin for construction of a fiberglass fuel tank to make a small > test. Make a 2" by 4" test laminate of polyester and fiberglass. Put into > a quart jar of AVGAS and MOGAS for about 1 month. You could weigh before > and after if you've got an accurate scale, but I think you'll discover the > discoloration of the AVGAS and MOGAS plus the somewhat slimy feel of your > test coupon will change your mind about the chemical resistance of > polyester resins. > Gordon > > Original Message: > -----------------
RE: Pietenpol-List: Fiberglass Construction
Original Posted By:> Rcaprd(at)aol.com
Subject: RE: Pietenpol-List: Fiberglass ConstructionGordon,I take it you are strongly recommending epoxy resin for the fiberglasstank, right? I have never been a fan of polyester resin compared to epoxy. Alex Sloan-------------- Original message -------------- > > > As a polymer chemist I highly recommend to anyone considering using > polyester resin for construction of a fiberglass fuel tank to make asmall > test. Make a 2" by 4" test laminate of polyester and fiberglass. Put into > a quart jar of AVGAS and MOGAS for about 1 month. You could weigh before > and after if you've got an accurate scale, but I think you'll discoverthe > discoloration of the AVGAS and MOGAS plus the somewhat slimy feel of your > test coupon will change your mind about the chemical resistance of > polyester resins. > Gordon > > Original Message: > -----------------
Subject: RE: Pietenpol-List: Fiberglass ConstructionGordon,I take it you are strongly recommending epoxy resin for the fiberglasstank, right? I have never been a fan of polyester resin compared to epoxy. Alex Sloan-------------- Original message -------------- > > > As a polymer chemist I highly recommend to anyone considering using > polyester resin for construction of a fiberglass fuel tank to make asmall > test. Make a 2" by 4" test laminate of polyester and fiberglass. Put into > a quart jar of AVGAS and MOGAS for about 1 month. You could weigh before > and after if you've got an accurate scale, but I think you'll discoverthe > discoloration of the AVGAS and MOGAS plus the somewhat slimy feel of your > test coupon will change your mind about the chemical resistance of > polyester resins. > Gordon > > Original Message: > -----------------
RE: Pietenpol-List: Fiberglass Construction
Original Posted By: alexms1(at)comcast.net
Each resin has it's place and function. In terms of chemical resistence itgoes like this: epoxy based vinyl ester is best, a post cured epoxy is nextand then comes polyester for some things like water. If MOGAS and AVGASwas pure aliphatics C-7 and C-8's hydrocarbons then maybe polyester wouldhold up better, but gasoline of all types has a lot of aromatics and someethers in it now that lead is dead in fuel. MOGAS changes from region toregion and season to season to fit the climate, these additives love toscarf up polymers like polyester.When no-lead came out 25 years ago, we had to redo all the test on RAE andSaf-t-poxy for Rutan to insure the composite planes of his design didn'tdissolve into a great big puddle of plastic. These tests were 2 years ofsubmersion in all types of gasoline, weighed before and after on a scaleaccurate to 0.001 grams. Epoxy holds up.If someone out there has a polyester tank, and leaks do appear or your fuelfilters/carb gets a gummy deposit, step back and punt. Or take the thingout, dry it out, cut it in half, relaminate the inside with Derakane and acouple plies of glass.One of the steps I left out in my last email for those using the "lostmold" method of making their composite tanks: if you don't use epoxy anddecide to use Derakane, you have to coat the foam mold with a layer ofplaster to keep the styrene in the Derakane from eating the mold whileyou're making your laminates. Go to Home Depot and buy a gallon of normalplaster patching compound, spread it thin and smoothly on the carved stryoand let dry, then go ahead with your laminations.Gordon BowenOriginal Message:-----------------
Each resin has it's place and function. In terms of chemical resistence itgoes like this: epoxy based vinyl ester is best, a post cured epoxy is nextand then comes polyester for some things like water. If MOGAS and AVGASwas pure aliphatics C-7 and C-8's hydrocarbons then maybe polyester wouldhold up better, but gasoline of all types has a lot of aromatics and someethers in it now that lead is dead in fuel. MOGAS changes from region toregion and season to season to fit the climate, these additives love toscarf up polymers like polyester.When no-lead came out 25 years ago, we had to redo all the test on RAE andSaf-t-poxy for Rutan to insure the composite planes of his design didn'tdissolve into a great big puddle of plastic. These tests were 2 years ofsubmersion in all types of gasoline, weighed before and after on a scaleaccurate to 0.001 grams. Epoxy holds up.If someone out there has a polyester tank, and leaks do appear or your fuelfilters/carb gets a gummy deposit, step back and punt. Or take the thingout, dry it out, cut it in half, relaminate the inside with Derakane and acouple plies of glass.One of the steps I left out in my last email for those using the "lostmold" method of making their composite tanks: if you don't use epoxy anddecide to use Derakane, you have to coat the foam mold with a layer ofplaster to keep the styrene in the Derakane from eating the mold whileyou're making your laminates. Go to Home Depot and buy a gallon of normalplaster patching compound, spread it thin and smoothly on the carved stryoand let dry, then go ahead with your laminations.Gordon BowenOriginal Message:-----------------
Re: Pietenpol-List: Fiberglass Construction
Original Posted By: N321TX(at)wmconnect.com
Subject: Re: Pietenpol-List: Fiberglass ConstructionGordon,I wish I would have seen this post about all this epoxy stuff. I built my wing tank in December of '98, and used a sloshing solution called '5000L'. Atthe time, this is the method that several local builders used. Maybe the sloshing solution saved the polyester resin. I've done quite a few inspectionsinside the tank, and it still seems all right. I didn't use the sloshing solution in the cowl tank, that I built in January '03. I've never found any goo,or fibers, in the gascolator, and I inspect it regularly. I'll have a very close look inside both tanks, with my bore scope, as regular inspections. I'mvery careful not to use fuel with alcohol, and the fuel I use at my home airportis 100LL. Ya never know, though. The next two tanks I build, will be for my Wittman Tailwind W10. I'll use West System Epoxy resin, and I plan on using Carbon Fiber for the 35 gallontank behind the firewall, and an auxiliary tank in the baggage compartment. The West System dosen't mention weather it is epoxy based vinyl ester.Gordon, is the West System epoxy based vinyl ester ?Chuck G.________________________________________________________________________________
Subject: Re: Pietenpol-List: Fiberglass ConstructionGordon,I wish I would have seen this post about all this epoxy stuff. I built my wing tank in December of '98, and used a sloshing solution called '5000L'. Atthe time, this is the method that several local builders used. Maybe the sloshing solution saved the polyester resin. I've done quite a few inspectionsinside the tank, and it still seems all right. I didn't use the sloshing solution in the cowl tank, that I built in January '03. I've never found any goo,or fibers, in the gascolator, and I inspect it regularly. I'll have a very close look inside both tanks, with my bore scope, as regular inspections. I'mvery careful not to use fuel with alcohol, and the fuel I use at my home airportis 100LL. Ya never know, though. The next two tanks I build, will be for my Wittman Tailwind W10. I'll use West System Epoxy resin, and I plan on using Carbon Fiber for the 35 gallontank behind the firewall, and an auxiliary tank in the baggage compartment. The West System dosen't mention weather it is epoxy based vinyl ester.Gordon, is the West System epoxy based vinyl ester ?Chuck G.________________________________________________________________________________
Re: Pietenpol-List: Fiberglass Construction
Original Posted By: BARNSTMR(at)aol.com
Subject: Re: Pietenpol-List: Fiberglass ConstructionGordon,I wish I would have seen this post about all this epoxy stuff. I built my wing tank in December of '98, and used a sloshing solution called '5000L'. At the time, this is the method that several local builders used. Maybe the sloshing solution saved the polyester resin. I've done quite a fewinspections inside the tank, and it still seems all right. I didn't use the sloshing solution in the cowl tank, that I built in January '03. I've never foundany goo, or fibers, in the gascolator, and I inspect it regularly. I'll have a very close look inside both tanks, with my bore scope, as regular inspections. I'm very careful not to use fuel with alcohol, and the fuel I use at my homeairport is 100LL. Ya never know, though. The next two tanks I build, will be for my Wittman Tailwind W10. I'll use West System Epoxy resin, and I plan on using Carbon Fiber for the 35gallon tank behind the firewall, and an auxiliary tank in the baggage compartment. The West System dosen't mention weather it is epoxy based vinyl ester.Gordon, is the West System epoxy based vinyl ester ?Chuck G.________________________________________________________________________________
Subject: Re: Pietenpol-List: Fiberglass ConstructionGordon,I wish I would have seen this post about all this epoxy stuff. I built my wing tank in December of '98, and used a sloshing solution called '5000L'. At the time, this is the method that several local builders used. Maybe the sloshing solution saved the polyester resin. I've done quite a fewinspections inside the tank, and it still seems all right. I didn't use the sloshing solution in the cowl tank, that I built in January '03. I've never foundany goo, or fibers, in the gascolator, and I inspect it regularly. I'll have a very close look inside both tanks, with my bore scope, as regular inspections. I'm very careful not to use fuel with alcohol, and the fuel I use at my homeairport is 100LL. Ya never know, though. The next two tanks I build, will be for my Wittman Tailwind W10. I'll use West System Epoxy resin, and I plan on using Carbon Fiber for the 35gallon tank behind the firewall, and an auxiliary tank in the baggage compartment. The West System dosen't mention weather it is epoxy based vinyl ester.Gordon, is the West System epoxy based vinyl ester ?Chuck G.________________________________________________________________________________
Re: Pietenpol-List: Fiberglass Construction
Original Posted By: Gary Gower
Subject: Re: Pietenpol-List: Fiberglass ConstructionYep, I'm going to be using your mold. I just forgot what you used when I picked it up from you several months ago, and it'll stay here until I get wordwho gets it next.Thanks,S.B.________________________________________________________________________________Date: Thu, 23 Dec 2004 23:06:30 -0800 (PST)
Subject: Re: Pietenpol-List: Fiberglass ConstructionYep, I'm going to be using your mold. I just forgot what you used when I picked it up from you several months ago, and it'll stay here until I get wordwho gets it next.Thanks,S.B.________________________________________________________________________________Date: Thu, 23 Dec 2004 23:06:30 -0800 (PST)
Re: Pietenpol-List: Fiberglass Construction
Original Posted By: Javier Cruz
Re: Pietenpol-List: Fiberglass Construction
Original Posted By: Rcaprd(at)aol.com
Chuck,Glad you've had good luck with sloshing rubber in the tank, it seems towork in some cases, but didn't for the Osprey tanks I had to rebuild, thegas got under the area around the drain sump and ate it's way thru thepolyester eventually. The Osprey has been around since early 70's andsomeone decided to start selling wing tanks as an after thought, theoriginal designer didn't specify what type of resin to use for in-fuselagetanks. Lots of rebuilds were done and lots of slosh sold.Derakane is the brand name from Dow for their epoxy based vinyl ester resinsystem. It's in the Spruce catalog. It's main commerical usage is forchemical storage tanks including all the gasoline in-ground fiberglasstanks at gas stations. The commerical folks like it because it's sprayablewith a chopper gun just like polyesters. For most builders it's a littletoo tricky to work with, so they stick with any good epoxy resin systemlike West or System 3.Gordon Original Message:-----------------
Chuck,Glad you've had good luck with sloshing rubber in the tank, it seems towork in some cases, but didn't for the Osprey tanks I had to rebuild, thegas got under the area around the drain sump and ate it's way thru thepolyester eventually. The Osprey has been around since early 70's andsomeone decided to start selling wing tanks as an after thought, theoriginal designer didn't specify what type of resin to use for in-fuselagetanks. Lots of rebuilds were done and lots of slosh sold.Derakane is the brand name from Dow for their epoxy based vinyl ester resinsystem. It's in the Spruce catalog. It's main commerical usage is forchemical storage tanks including all the gasoline in-ground fiberglasstanks at gas stations. The commerical folks like it because it's sprayablewith a chopper gun just like polyesters. For most builders it's a littletoo tricky to work with, so they stick with any good epoxy resin systemlike West or System 3.Gordon Original Message:-----------------
> Pietenpol-List: Fiberglass Construction
Original Posted By:
> To: pietenpol-list(at)matronics.com > Subject: Pietenpol-List: Fiberglass Construction > > > > In a message dated 12/23/04 1:00:37 PM Central Standard Time, > N321TX(at)wmconnect.com writes: > > > #1. Who is a good source (Aircraft Spruce?) for the resin and cloth? > #2. What weave material is recommended? > > Thanks, > Sterling >> > > Sterling, > Are you using the fuel tank mould that I loaned you ? If so, please > use > enough release agent, so as not to destroy it !! There is a couple of > other > folks that will need it. It's a really good mould (capacity - 10.7 gal.), > and > we can pass it around to others, when you are done with it. (It is for the > nose cowling fuel tank for plans dimension short fuselage.) I designed it > so > the bottom of the tank slopes forward, when the tail is on the ground, so > any > water in the fuel finds it's way to the outlet. There is no place where a > pocket of water will collect. I might need it again, too, if I ever get > any > alcohol in my fuel !! > > Here is the way I built both my tanks, and J3 type nose > bowl: > I used Polyester Resin (for auto body repair) on both tanks. It's > cheaper than Epoxy, and is a lower viscosity which aids in wetting out the > fabric. > However, if I build another tank, I will use the West System Epoxy Resin > 105, > with the 206 hardener. If you go this route, it is very convenient to buy > the > pumps that go with the cans, which dispenses the material at the proper > ratio. > Never handle any cloth with your bare hands, or touch any area where > you > are going to do an additional lay-up, or skin oil will prevent the resin > from > saturating the cloth in that area. > You have to be FAST if you use the Polyester Resin, because after you > put > the hardener in...it Kicks in only about 5 to 7 minutes, depending on how > many drops you put in. West System has a lot longer pot life (work time). > Have > all the fabric cut, pre-fit, and stacked in the order they lay. I can't > say > enough about preparation, before you add the hardener. You can lengthen > the > working time some, by using a few drops less than recommended, but once it > starts to jell, forget about proceeding any further. The challenge of > doing > composite work, is to get 100% saturation, using as little resin as > possible, with > no fabric separation. The way we achieve this at work, is 'Vacuum > Bagging'. > One of the faults of the Polyester Resin, is that it is NOT alcohol > resistant. So far, I haven't had any problem. > Fiberglass Cloth: > I have a source here in Wichita, where I purchase the cloth, in all > sizes. It ain't cheap !! Seems like I had over $35 or $40 bucks for the > cloth in > the nose tank and nose bowl. I used two different weigh fabric - Light > weight, and Medium weight. > The first layer down, I used light weight. Then two layers of medium > weight, > then the last layer down in the Mould I used another layer of light weight. > > The difficult part is to get the cloth to stay down in the corners. It > always > wants to spring back out of the inside corners, no matter how many times > you > poke it back in. Light weigh cloth stays down in the corners much easier, > because the cloth is thinner, and bends easier. This is the reason I used > corner > pieces in the mould, so the fabric only has to form to 45, instead of 90. > > After the resin cures, and you pop the bottom and top out of the mould, you > need to carefully sand the edges, so you get a nice tight fit, preferably a > 45 > miter fit (that's what I did) then glue them together with the resin you've > been using. After they are glued together, put 3 layers around the entire > corner edge, stepping out from 2" for the first layer down, up to about 4" > for the > last layer down. You always have to sand the shinny off, before adding any > additional layers. After complete, leak test with a balloon, like Tony > Bengalis > recommends. Then you should calibrate it at the gas station. Set the tank > in the static laden position (the angle it will be at when the tail is on > the > ground), and add one gallon of fuel at a time, dip your 'Calibrated Dip > Stick' > in, and mark each gallon increment. The distance between these marks vary, > because of the shape of the tank. I didn't have any leaks in either of the > fuel > tanks I built. > I built the Smoke Tank with just two layers of fiberglass, moulded > around > cereal box the right dimension, but used the West System Epoxy. It seemed > like the cloth was wetted out good, but it had two places where the baby > oil > seeped through, and dripped about one drip every 6 minutes. I fixed them > by > cleaning first with Brake Clean, then sanding the area, then some more > Brake Clean > (with clean cloth and no finger prints), then used 5 minute epoxy, and two > layers of cloth. > > Chuck Gantzer > NX770CG > Merry Christmas To All !! > > > > > > > > > > > > > > > > > > > Gordon,I take it you are strongly recommending epoxy resin for the fiberglass tank,right? I have never been a fan of polyester resin compared to epoxy. Alex Sloan-------------- Original message -------------- -- Pietenpol-Listmessage posted by: "gbowen(at)ptialaska.net" As a polymer chemist I highly recommend to anyone consideringusing polyester resin for construction of a fiberglass fueltank to make a small test. Make a 2" by 4" test laminate of polyesterand fiberglass. Put into a quart jar of AVGAS and MOGAS for about 1month. You could weigh before and after if you've got an accurate scale,but I think you'll discover the discoloration of the AVGAS and MOGASplus the somewhat slimy feel of your test coupon will change yourmind about the chemical resistance of polyester resins. Gordon Original Message: -----------------
> To: pietenpol-list(at)matronics.com > Subject: Pietenpol-List: Fiberglass Construction > > > > In a message dated 12/23/04 1:00:37 PM Central Standard Time, > N321TX(at)wmconnect.com writes: > > > #1. Who is a good source (Aircraft Spruce?) for the resin and cloth? > #2. What weave material is recommended? > > Thanks, > Sterling >> > > Sterling, > Are you using the fuel tank mould that I loaned you ? If so, please > use > enough release agent, so as not to destroy it !! There is a couple of > other > folks that will need it. It's a really good mould (capacity - 10.7 gal.), > and > we can pass it around to others, when you are done with it. (It is for the > nose cowling fuel tank for plans dimension short fuselage.) I designed it > so > the bottom of the tank slopes forward, when the tail is on the ground, so > any > water in the fuel finds it's way to the outlet. There is no place where a > pocket of water will collect. I might need it again, too, if I ever get > any > alcohol in my fuel !! > > Here is the way I built both my tanks, and J3 type nose > bowl: > I used Polyester Resin (for auto body repair) on both tanks. It's > cheaper than Epoxy, and is a lower viscosity which aids in wetting out the > fabric. > However, if I build another tank, I will use the West System Epoxy Resin > 105, > with the 206 hardener. If you go this route, it is very convenient to buy > the > pumps that go with the cans, which dispenses the material at the proper > ratio. > Never handle any cloth with your bare hands, or touch any area where > you > are going to do an additional lay-up, or skin oil will prevent the resin > from > saturating the cloth in that area. > You have to be FAST if you use the Polyester Resin, because after you > put > the hardener in...it Kicks in only about 5 to 7 minutes, depending on how > many drops you put in. West System has a lot longer pot life (work time). > Have > all the fabric cut, pre-fit, and stacked in the order they lay. I can't > say > enough about preparation, before you add the hardener. You can lengthen > the > working time some, by using a few drops less than recommended, but once it > starts to jell, forget about proceeding any further. The challenge of > doing > composite work, is to get 100% saturation, using as little resin as > possible, with > no fabric separation. The way we achieve this at work, is 'Vacuum > Bagging'. > One of the faults of the Polyester Resin, is that it is NOT alcohol > resistant. So far, I haven't had any problem. > Fiberglass Cloth: > I have a source here in Wichita, where I purchase the cloth, in all > sizes. It ain't cheap !! Seems like I had over $35 or $40 bucks for the > cloth in > the nose tank and nose bowl. I used two different weigh fabric - Light > weight, and Medium weight. > The first layer down, I used light weight. Then two layers of medium > weight, > then the last layer down in the Mould I used another layer of light weight. > > The difficult part is to get the cloth to stay down in the corners. It > always > wants to spring back out of the inside corners, no matter how many times > you > poke it back in. Light weigh cloth stays down in the corners much easier, > because the cloth is thinner, and bends easier. This is the reason I used > corner > pieces in the mould, so the fabric only has to form to 45, instead of 90. > > After the resin cures, and you pop the bottom and top out of the mould, you > need to carefully sand the edges, so you get a nice tight fit, preferably a > 45 > miter fit (that's what I did) then glue them together with the resin you've > been using. After they are glued together, put 3 layers around the entire > corner edge, stepping out from 2" for the first layer down, up to about 4" > for the > last layer down. You always have to sand the shinny off, before adding any > additional layers. After complete, leak test with a balloon, like Tony > Bengalis > recommends. Then you should calibrate it at the gas station. Set the tank > in the static laden position (the angle it will be at when the tail is on > the > ground), and add one gallon of fuel at a time, dip your 'Calibrated Dip > Stick' > in, and mark each gallon increment. The distance between these marks vary, > because of the shape of the tank. I didn't have any leaks in either of the > fuel > tanks I built. > I built the Smoke Tank with just two layers of fiberglass, moulded > around > cereal box the right dimension, but used the West System Epoxy. It seemed > like the cloth was wetted out good, but it had two places where the baby > oil > seeped through, and dripped about one drip every 6 minutes. I fixed them > by > cleaning first with Brake Clean, then sanding the area, then some more > Brake Clean > (with clean cloth and no finger prints), then used 5 minute epoxy, and two > layers of cloth. > > Chuck Gantzer > NX770CG > Merry Christmas To All !! > > > > > > > > > > > > > > > > > > > Gordon,I take it you are strongly recommending epoxy resin for the fiberglass tank,right? I have never been a fan of polyester resin compared to epoxy. Alex Sloan-------------- Original message -------------- -- Pietenpol-Listmessage posted by: "gbowen(at)ptialaska.net" As a polymer chemist I highly recommend to anyone consideringusing polyester resin for construction of a fiberglass fueltank to make a small test. Make a 2" by 4" test laminate of polyesterand fiberglass. Put into a quart jar of AVGAS and MOGAS for about 1month. You could weigh before and after if you've got an accurate scale,but I think you'll discover the discoloration of the AVGAS and MOGASplus the somewhat slimy feel of your test coupon will change yourmind about the chemical resistance of polyester resins. Gordon Original Message: -----------------
Pietenpol-List:
Original Posted By: "gbowen(at)ptialaska.net"
To: pietenpol-list(at)matronics.com Subject: Pietenpol-List:Fiberglass Construction -- Pietenpol-Listmessage posted by: Rcaprd(at)aol.com In a message dated 12/23/041:00:37 PM Central Standard Time, N321TX(at)wmconnect.com writes: I'm going to be making a fuel tank for an air campersoon. #1. Who is a good source (Aircraft Spruce?) for theresin and cloth? #2. What weave material is recommended? Thanks, Sterling Sterling, Are you using the fuel tank mould that I loaned you ? If so, please use enough release agent, so as not to destroy it !! There is a coupleof other folks that will need it. It's a really good mould(capacity - 10.7 gal.), and we can pass it around to others,when you are done with it. (It is for the nose cowling fuel tank for plans dimension short fuselage.) I designed it so the bottom of the tank slopes forward, when the tail is on theground, so any water in the fuel finds it's way to the outlet.There is no place where a pocket of water will collect. I mightneed it again, too, if I ever get any alcohol in my fuel !! Here is the way I built both my tanks, and J3 type nose bowl: I used Polyester Resin (for auto body repair) on both tanks.It's cheaper than Epoxy, and is a lower viscosity which aids in wettingout the fabric. However, if I build another tank, I willuse the West System Epoxy Resin 105, with the 206 hardener.If you go this route, it is very convenient to buy the pumpsthat go with the cans, which dispenses the material at the proper ratio. Never handle any cloth with your bar e hands, or touch any area where you are going to do an additionallay-up, or skin oil will prevent the resin from saturatingthe cloth in that area. You have to be FAST if you use the PolyesterResin, because after you put the hardener in...it Kicksin only about 5 to 7 minutes, depending on how many drops you put in.West System has a lot longer pot life (work time). Have allthe fabric cut, pre-fit, and stacked in the order they lay. I can't say enough about preparation, before you add the hardener. You canlengthen the working time some, by using a few drops less thanrecommended, but once it starts to jell, forget about proceeding anyfurther. The challenge of doing composite work, is to get100% saturation, using as little resin as possible, with nofabric separation. The way we achieve this at work, is 'Vacuum Bagging'. One of the faults of the Polyester Resin,is that it is NOT alcohol resistant. So far, I haven't had any problem. Fiberglass Cloth: I have a source here in Wichita, whereI purchase the cloth, in all sizes. It ain't cheap !! Seems like Ihad over $35 or $40 bucks for the cloth in the nose tank andnose bowl. I used two different weigh fabric - Light weight, and Mediumweight. The first layer down, I used light weight. Then two layersof medium weight, then the last layer down in the Mould Iused another layer of light weight. The difficult part is toget the cloth to stay down in the corners. It always wantsto spring back out of the inside corners, no matter how many times you poke it back in. Light weigh cloth stays down in the corners mucheasier, because the cloth is thinner, and be nds easier. This is the reason I used corner pieces in the mould,so the fabric only has to form to 45, instead of 90. After the resin cures, and you pop the bottom and top out of the mould, you need to carefully sand the edges, so you get a nice tight fit, preferablya 45 miter fit (that's what I did) then glue them togetherwith the resin you've been using. After they are glued together,put 3 layers around the entire corner edge, stepping out from 2" forthe first layer down, up to about 4" for the last layer down.You always have to sand the shinny off, before adding any additionallayers. After complete, leak test with a balloon, like Tony Bengalis recommends. Then you should calibrate it at the gas station. Set thetank in the static laden position (the angle it will be at when thetail is on the ground), and add on e gallon of fuel at a time, dip your 'Calibrated Dip Stick' in, and mark each gallon increment. The distance between these marks vary, because of the shape of the tank. I didn't have any leaks in either of the fuel tanks I built. I built the Smoke Tank withjust two layers of fiberglass, moulded around cereal box theright dimension, but used the West System Epoxy. It seemed like thecloth was wetted out good, but it had two places where the baby oil seeped through, and dripped about one drip every 6 minutes. I fixed them by cleaning first with Brake Clean, then sanding the area,then some more Brake Clean (with clean cloth and no fingerprints), then used 5 minute epoxy, and two layers of cloth. Chuck Gantzer NX770CG Merry Christmas To All !! <________________________________________________________________________________
To: pietenpol-list(at)matronics.com Subject: Pietenpol-List:Fiberglass Construction -- Pietenpol-Listmessage posted by: Rcaprd(at)aol.com In a message dated 12/23/041:00:37 PM Central Standard Time, N321TX(at)wmconnect.com writes: I'm going to be making a fuel tank for an air campersoon. #1. Who is a good source (Aircraft Spruce?) for theresin and cloth? #2. What weave material is recommended? Thanks, Sterling Sterling, Are you using the fuel tank mould that I loaned you ? If so, please use enough release agent, so as not to destroy it !! There is a coupleof other folks that will need it. It's a really good mould(capacity - 10.7 gal.), and we can pass it around to others,when you are done with it. (It is for the nose cowling fuel tank for plans dimension short fuselage.) I designed it so the bottom of the tank slopes forward, when the tail is on theground, so any water in the fuel finds it's way to the outlet.There is no place where a pocket of water will collect. I mightneed it again, too, if I ever get any alcohol in my fuel !! Here is the way I built both my tanks, and J3 type nose bowl: I used Polyester Resin (for auto body repair) on both tanks.It's cheaper than Epoxy, and is a lower viscosity which aids in wettingout the fabric. However, if I build another tank, I willuse the West System Epoxy Resin 105, with the 206 hardener.If you go this route, it is very convenient to buy the pumpsthat go with the cans, which dispenses the material at the proper ratio. Never handle any cloth with your bar e hands, or touch any area where you are going to do an additionallay-up, or skin oil will prevent the resin from saturatingthe cloth in that area. You have to be FAST if you use the PolyesterResin, because after you put the hardener in...it Kicksin only about 5 to 7 minutes, depending on how many drops you put in.West System has a lot longer pot life (work time). Have allthe fabric cut, pre-fit, and stacked in the order they lay. I can't say enough about preparation, before you add the hardener. You canlengthen the working time some, by using a few drops less thanrecommended, but once it starts to jell, forget about proceeding anyfurther. The challenge of doing composite work, is to get100% saturation, using as little resin as possible, with nofabric separation. The way we achieve this at work, is 'Vacuum Bagging'. One of the faults of the Polyester Resin,is that it is NOT alcohol resistant. So far, I haven't had any problem. Fiberglass Cloth: I have a source here in Wichita, whereI purchase the cloth, in all sizes. It ain't cheap !! Seems like Ihad over $35 or $40 bucks for the cloth in the nose tank andnose bowl. I used two different weigh fabric - Light weight, and Mediumweight. The first layer down, I used light weight. Then two layersof medium weight, then the last layer down in the Mould Iused another layer of light weight. The difficult part is toget the cloth to stay down in the corners. It always wantsto spring back out of the inside corners, no matter how many times you poke it back in. Light weigh cloth stays down in the corners mucheasier, because the cloth is thinner, and be nds easier. This is the reason I used corner pieces in the mould,so the fabric only has to form to 45, instead of 90. After the resin cures, and you pop the bottom and top out of the mould, you need to carefully sand the edges, so you get a nice tight fit, preferablya 45 miter fit (that's what I did) then glue them togetherwith the resin you've been using. After they are glued together,put 3 layers around the entire corner edge, stepping out from 2" forthe first layer down, up to about 4" for the last layer down.You always have to sand the shinny off, before adding any additionallayers. After complete, leak test with a balloon, like Tony Bengalis recommends. Then you should calibrate it at the gas station. Set thetank in the static laden position (the angle it will be at when thetail is on the ground), and add on e gallon of fuel at a time, dip your 'Calibrated Dip Stick' in, and mark each gallon increment. The distance between these marks vary, because of the shape of the tank. I didn't have any leaks in either of the fuel tanks I built. I built the Smoke Tank withjust two layers of fiberglass, moulded around cereal box theright dimension, but used the West System Epoxy. It seemed like thecloth was wetted out good, but it had two places where the baby oil seeped through, and dripped about one drip every 6 minutes. I fixed them by cleaning first with Brake Clean, then sanding the area,then some more Brake Clean (with clean cloth and no fingerprints), then used 5 minute epoxy, and two layers of cloth. Chuck Gantzer NX770CG Merry Christmas To All !! <________________________________________________________________________________
> Pietenpol-List: Fiberglass Construction
Original Posted By: Rcaprd(at)aol.com
> To: pietenpol-list(at)matronics.com > Subject: Pietenpol-List: Fiberglass Construction > > > > In a message dated 12/23/04 1:00:37 PM Central Standard Time, > N321TX(at)wmconnect.com writes: > > > #1. Who is a good source (Aircraft Spruce?) for the resin and cloth? > #2. What weave material is recommended? > > Thanks, > Sterling >> > > Sterling, > Are you using the fuel tank mould that I loaned you ? If so, please > use > enough release agent, so as not to destroy it !! There is a couple of > other > folks that will need it. It's a really good mould (capacity - 10.7 gal.), > and > we can pass it around to others, when you are done with it. (It is forthe > nose cowling fuel tank for plans dimension short fuselage.) I designed it > so > the bottom of the tank slopes forward, when the tail is on the ground, so > any > water in the fuel finds it's way to the outlet. There is no place where a > pocket of water will collect. I might need it again, too, if I ever get > any > alcohol in my fuel !! > > Here is the way I built both my tanks, and J3 type nose > bowl: > I used Polyester Resin (for auto body repair) on both tanks. It's > cheaper than Epoxy, and is a lower viscosity which aids in wetting outthe > fabric. > However, if I build another tank, I will use the West System Epoxy Resin > 105, > with the 206 hardener. If you go this route, it is very convenient to buy > the > pumps that go with the cans, which dispenses the material at the proper > ratio. > Never handle any cloth with your bare hands, or touch any area where > you > are going to do an additional lay-up, or skin oil will prevent the resin > from > saturating the cloth in that area. > You have to be FAST if you use the Polyester Resin, because after you > put > the hardener in...it Kicks in only about 5 to 7 minutes, depending on how > many drops you put in. West System has a lot longer pot life (work time). > Have > all the fabric cut, pre-fit, and stacked in the order they lay. I can't > say > enough about preparation, before you add the hardener. You can lengthen > the > working time some, by using a few drops less than recommended, but onceit > starts to jell, forget about proceeding any further. The challenge of > doing > composite work, is to get 100% saturation, using as little resin as > possible, with > no fabric separation. The way we achieve this at work, is 'Vacuum > Bagging'. > One of the faults of the Polyester Resin, is that it is NOT alcohol > resistant. So far, I haven't had any problem. > Fiberglass Cloth: > I have a source here in Wichita, where I purchase the cloth, in all > sizes. It ain't cheap !! Seems like I had over $35 or $40 bucks for the > cloth in > the nose tank and nose bowl. I used two different weigh fabric - Light > weight, and Medium weight. > The first layer down, I used light weight. Then two layers of medium > weight, > then the last layer down in the Mould I used another layer of lightweight. > > The difficult part is to get the cloth to stay down in the corners. It > always > wants to spring back out of the inside corners, no matter how many times > you > poke it back in. Light weigh cloth stays down in the corners much easier, > because the cloth is thinner, and bends easier. This is the reason I used > corner > pieces in the mould, so the fabric only has to form to 45, instead of90. > > After the resin cures, and you pop the bottom and top out of the mould,you > need to carefully sand the edges, so you get a nice tight fit, preferablya > 45 > miter fit (that's what I did) then glue them together with the resinyou've > been using. After they are glued together, put 3 layers around the entire > corner edge, stepping out from 2" for the first layer down, up to about4" > for the > last layer down. You always have to sand the shinny off, before addingany > additional layers. After complete, leak test with a balloon, like Tony > Bengalis > recommends. Then you should calibrate it at the gas station. Set the tank > in the static laden position (the angle it will be at when the tail is on > the > ground), and add one gallon of fuel at a time, dip your 'Calibrated Dip > Stick' > in, and mark each gallon increment. The distance between these marksvary, > because of the shape of the tank. I didn't have any leaks in either ofthe > fuel > tanks I built. > I built the Smoke Tank with just two layers of fiberglass, moulded > around > cereal box the right dimension, but used the West System Epoxy. It seemed > like the cloth was wetted out good, but it had two places where the baby > oil > seeped through, and dripped about one drip every 6 minutes. I fixed them > by > cleaning first with Brake Clean, then sanding the area, then some more > Brake Clean > (with clean cloth and no finger prints), then used 5 minute epoxy, andtwo > layers of cloth. > > Chuck Gantzer > NX770CG > Merry Christmas To All !! > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
> To: pietenpol-list(at)matronics.com > Subject: Pietenpol-List: Fiberglass Construction > > > > In a message dated 12/23/04 1:00:37 PM Central Standard Time, > N321TX(at)wmconnect.com writes: > > > #1. Who is a good source (Aircraft Spruce?) for the resin and cloth? > #2. What weave material is recommended? > > Thanks, > Sterling >> > > Sterling, > Are you using the fuel tank mould that I loaned you ? If so, please > use > enough release agent, so as not to destroy it !! There is a couple of > other > folks that will need it. It's a really good mould (capacity - 10.7 gal.), > and > we can pass it around to others, when you are done with it. (It is forthe > nose cowling fuel tank for plans dimension short fuselage.) I designed it > so > the bottom of the tank slopes forward, when the tail is on the ground, so > any > water in the fuel finds it's way to the outlet. There is no place where a > pocket of water will collect. I might need it again, too, if I ever get > any > alcohol in my fuel !! > > Here is the way I built both my tanks, and J3 type nose > bowl: > I used Polyester Resin (for auto body repair) on both tanks. It's > cheaper than Epoxy, and is a lower viscosity which aids in wetting outthe > fabric. > However, if I build another tank, I will use the West System Epoxy Resin > 105, > with the 206 hardener. If you go this route, it is very convenient to buy > the > pumps that go with the cans, which dispenses the material at the proper > ratio. > Never handle any cloth with your bare hands, or touch any area where > you > are going to do an additional lay-up, or skin oil will prevent the resin > from > saturating the cloth in that area. > You have to be FAST if you use the Polyester Resin, because after you > put > the hardener in...it Kicks in only about 5 to 7 minutes, depending on how > many drops you put in. West System has a lot longer pot life (work time). > Have > all the fabric cut, pre-fit, and stacked in the order they lay. I can't > say > enough about preparation, before you add the hardener. You can lengthen > the > working time some, by using a few drops less than recommended, but onceit > starts to jell, forget about proceeding any further. The challenge of > doing > composite work, is to get 100% saturation, using as little resin as > possible, with > no fabric separation. The way we achieve this at work, is 'Vacuum > Bagging'. > One of the faults of the Polyester Resin, is that it is NOT alcohol > resistant. So far, I haven't had any problem. > Fiberglass Cloth: > I have a source here in Wichita, where I purchase the cloth, in all > sizes. It ain't cheap !! Seems like I had over $35 or $40 bucks for the > cloth in > the nose tank and nose bowl. I used two different weigh fabric - Light > weight, and Medium weight. > The first layer down, I used light weight. Then two layers of medium > weight, > then the last layer down in the Mould I used another layer of lightweight. > > The difficult part is to get the cloth to stay down in the corners. It > always > wants to spring back out of the inside corners, no matter how many times > you > poke it back in. Light weigh cloth stays down in the corners much easier, > because the cloth is thinner, and bends easier. This is the reason I used > corner > pieces in the mould, so the fabric only has to form to 45, instead of90. > > After the resin cures, and you pop the bottom and top out of the mould,you > need to carefully sand the edges, so you get a nice tight fit, preferablya > 45 > miter fit (that's what I did) then glue them together with the resinyou've > been using. After they are glued together, put 3 layers around the entire > corner edge, stepping out from 2" for the first layer down, up to about4" > for the > last layer down. You always have to sand the shinny off, before addingany > additional layers. After complete, leak test with a balloon, like Tony > Bengalis > recommends. Then you should calibrate it at the gas station. Set the tank > in the static laden position (the angle it will be at when the tail is on > the > ground), and add one gallon of fuel at a time, dip your 'Calibrated Dip > Stick' > in, and mark each gallon increment. The distance between these marksvary, > because of the shape of the tank. I didn't have any leaks in either ofthe > fuel > tanks I built. > I built the Smoke Tank with just two layers of fiberglass, moulded > around > cereal box the right dimension, but used the West System Epoxy. It seemed > like the cloth was wetted out good, but it had two places where the baby > oil > seeped through, and dripped about one drip every 6 minutes. I fixed them > by > cleaning first with Brake Clean, then sanding the area, then some more > Brake Clean > (with clean cloth and no finger prints), then used 5 minute epoxy, andtwo > layers of cloth. > > Chuck Gantzer > NX770CG > Merry Christmas To All !! > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________