Original Posted By: "GlennThomas(at)flyingwood.com"
Subject: Pietenpol-List: Adhesive comparison test resultsI know this has been beaten around a bunch and not to ad to the confusion of what glue is best the latest test results are out on glue comparisons, some pretty interesting stuff when considering selecting adhesives for your project.EnjoyJohnhttp://discover.aol.com/memed/aolcom30tour________________________________________________________________________________
Pietenpol-List: Adhesive comparison test results
Re: Pietenpol-List: Adhesive comparison test results
Original Posted By: "Oscar Zuniga"
I guess the redeeming value in the article (although I will read it more closely later) is while there is not an advantage to using slowset epoxy, there is also no disadvantage (for those of us who used T-88). Is the article written with moisture and common aircraft application in mind? Thanks for sharing the info. It's interesting to read about things like this.Glenn W. ThomasStorrs, CThttp://www.flyingwood.com________________________________________________________________________________
I guess the redeeming value in the article (although I will read it more closely later) is while there is not an advantage to using slowset epoxy, there is also no disadvantage (for those of us who used T-88). Is the article written with moisture and common aircraft application in mind? Thanks for sharing the info. It's interesting to read about things like this.Glenn W. ThomasStorrs, CThttp://www.flyingwood.com________________________________________________________________________________
Re: Pietenpol-List: Adhesive comparison test results
Original Posted By: "jimboyer(at)hughes.net"
RE: Pietenpol-List: Adhesive comparison test results
Original Posted By: "Phillips, Jack"
Oscar,I am building a boat and mine is a skiff too but larger. It's a Glen-L design of stitch and glue construction. I have thus far used epoxy mixed with silica and micro ballons for the glue as they recommend but it can be a pain to mix that up every time. I have just started to use PL Premium adhesive on a few parts and so far it's great. Here's a link:http://www.stickwithpl.com/Products/det ... tID=14It's available at Home Depot and was $3.50 a tube a couple years ago when I last bought it. Might be more now. Supposedly it's comparable to 3M 5200 marine adhesive but much cheaper. I had to remove one part on my transom that I had glued with the PL and man it was tenacious. I had to grind and cut through it and the wood. There was no separation along the glue joint at all.If you do want to go the epoxy route, Glen-L offers a pre-thickened epoxy glue that you mix in a 1:1 ratio called Poxy-Grip. Link here: https://www.boatdesigns.com/products.asp?dept=287I'm thinking of buying some of this to finish my boat with and avoiding having to add the silica and micro.Eric>From: "Oscar Zuniga" >Reply-To: pietenpol-list(at)matronics.com>To: pietenpol-list(at)matronics.com>Subject: Pietenpol-List: Gorilla Glue- NOT!>Date: Wed, 15 Aug 2007 07:44:25 -0500>>>>I guess the link to the glue comparison doesn't come through on the digest, >so could someone please send it to me directly so I can see the study >results? I was thinking of using Gorilla Glue on a small boat project for >my grandsons (the "One Sheet Skiff", at >http://www3.sympatico.ca/herbert.mcleod/skiff.htm ) and want to see what >they say about it.>>Thanks.>>Oscar Zuniga>Air Camper NX41CC>San Antonio, TX>mailto: taildrags(at)hotmail.com>website at http://www.flysquirrel.net/piets/CorkyP ... _____>More photos, more messages, more storageget 2GB with Windows Live Hotmail.>>________________________________________________________________________________Subject: RE: Pietenpol-List: Adhesive comparison test resultsDate: Wed, 15 Aug 2007 14:02:41 -0400
Oscar,I am building a boat and mine is a skiff too but larger. It's a Glen-L design of stitch and glue construction. I have thus far used epoxy mixed with silica and micro ballons for the glue as they recommend but it can be a pain to mix that up every time. I have just started to use PL Premium adhesive on a few parts and so far it's great. Here's a link:http://www.stickwithpl.com/Products/det ... tID=14It's available at Home Depot and was $3.50 a tube a couple years ago when I last bought it. Might be more now. Supposedly it's comparable to 3M 5200 marine adhesive but much cheaper. I had to remove one part on my transom that I had glued with the PL and man it was tenacious. I had to grind and cut through it and the wood. There was no separation along the glue joint at all.If you do want to go the epoxy route, Glen-L offers a pre-thickened epoxy glue that you mix in a 1:1 ratio called Poxy-Grip. Link here: https://www.boatdesigns.com/products.asp?dept=287I'm thinking of buying some of this to finish my boat with and avoiding having to add the silica and micro.Eric>From: "Oscar Zuniga" >Reply-To: pietenpol-list(at)matronics.com>To: pietenpol-list(at)matronics.com>Subject: Pietenpol-List: Gorilla Glue- NOT!>Date: Wed, 15 Aug 2007 07:44:25 -0500>>>>I guess the link to the glue comparison doesn't come through on the digest, >so could someone please send it to me directly so I can see the study >results? I was thinking of using Gorilla Glue on a small boat project for >my grandsons (the "One Sheet Skiff", at >http://www3.sympatico.ca/herbert.mcleod/skiff.htm ) and want to see what >they say about it.>>Thanks.>>Oscar Zuniga>Air Camper NX41CC>San Antonio, TX>mailto: taildrags(at)hotmail.com>website at http://www.flysquirrel.net/piets/CorkyP ... _____>More photos, more messages, more storageget 2GB with Windows Live Hotmail.>>________________________________________________________________________________Subject: RE: Pietenpol-List: Adhesive comparison test resultsDate: Wed, 15 Aug 2007 14:02:41 -0400
Re: Pietenpol-List: Adhesive comparison test results
Original Posted By: "Gordon Bowen"
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RE: Pietenpol-List: Adhesives article
Original Posted By: "Jack T. Textor"
Not sure why previous post didn't come out right, so I rewrite my comments. I spent over 30 years as manager and chemist in the epoxy and urethane industry, Burt Rutan used only our epoxies on his fiberglass designs for over 25 years. Couple comments bout the article about wood glues, a) not all epoxies are formulated the same, actually there's probably over 300 in my notebooks alone, and I guess thousands out there in the formulation industry. Wood application epoxies are a special breed. They have to penetrate the wood fibers for physical bonding, but also chemically bond with the resins and H2O in the wood, to be effective. b.) different epoxies have different resist to weathering and aging ie. UV and oxidation. c.) different epoxies have differing amounts of thermplastic creep under sheer loads. Boston's Big Dig roof collapes found this out the hard way. They used accidentally the wrong epoxy formula to bond the bolts holding up the roof panels to the rock tunnel walls, under loaded sheer stress the epoxy creeped (flowed even when completely hardened) and the bolt bond failed. Epoxies used for homebuilt wood boats and aircraft are special, don't fool around, use only stuff known and tested for the application, ie. T-88, West Systems, System 3, Hexcel's, etc, all available from Airspruce or Wicks. If unsure contact the manufacturers tech service toll free call lines or their websites. The glue holding your wood plane together is your cheapest investment in the homebuilt but probably the most important, considering the metal parts are about 80% of the cost. Glues can fatigue just like metals or "flow" (creep) under stress loads. Setting on the flightline or in the hanger the glue is under stress just holding up the wings or holding the plane together. The article posted is for wood workers making furniture etc., and is very superficial in data.Gordon ________________________________________________________________________________Subject: RE: Pietenpol-List: Adhesives articleDate: Wed, 15 Aug 2007 15:19:32 -0500
Not sure why previous post didn't come out right, so I rewrite my comments. I spent over 30 years as manager and chemist in the epoxy and urethane industry, Burt Rutan used only our epoxies on his fiberglass designs for over 25 years. Couple comments bout the article about wood glues, a) not all epoxies are formulated the same, actually there's probably over 300 in my notebooks alone, and I guess thousands out there in the formulation industry. Wood application epoxies are a special breed. They have to penetrate the wood fibers for physical bonding, but also chemically bond with the resins and H2O in the wood, to be effective. b.) different epoxies have different resist to weathering and aging ie. UV and oxidation. c.) different epoxies have differing amounts of thermplastic creep under sheer loads. Boston's Big Dig roof collapes found this out the hard way. They used accidentally the wrong epoxy formula to bond the bolts holding up the roof panels to the rock tunnel walls, under loaded sheer stress the epoxy creeped (flowed even when completely hardened) and the bolt bond failed. Epoxies used for homebuilt wood boats and aircraft are special, don't fool around, use only stuff known and tested for the application, ie. T-88, West Systems, System 3, Hexcel's, etc, all available from Airspruce or Wicks. If unsure contact the manufacturers tech service toll free call lines or their websites. The glue holding your wood plane together is your cheapest investment in the homebuilt but probably the most important, considering the metal parts are about 80% of the cost. Glues can fatigue just like metals or "flow" (creep) under stress loads. Setting on the flightline or in the hanger the glue is under stress just holding up the wings or holding the plane together. The article posted is for wood workers making furniture etc., and is very superficial in data.Gordon ________________________________________________________________________________Subject: RE: Pietenpol-List: Adhesives articleDate: Wed, 15 Aug 2007 15:19:32 -0500
Re: Pietenpol-List: Adhesives article
Original Posted By: "Bill Weir"
Subject: Re: Pietenpol-List: Adhesives articleHaving posted the article, I have to say that Gordon's post is really reassuring. The way it turns out a friend of mine is a furniture maker and swearsby the Titebond products, actually suggested on several occasions that I buildusing Titebond III as an alternative to the epoxy's.I resisted the temptation to go cheep and went the West Systems epoxy, which I have been extremely happy working with for several reasons, primarily the mix pump system of a uniform batch every time. After reading the comparison chart I was again tempted to use the Titebond III product on some of the non structural parts for no particular reason other than ease of no having to mix a batch of system 3 epoxy.>From Gordon's perspective and background I made the right choice to resist the temptation of cheep and easy and remain with the tried and true proven system of meter mix and apply. For the record I always leave the project for therecommended set and cure time of 24 hours. Nothing like making a good choice.Gordon thanks again for shedding some much needed light on a topic that I have pondered and read about for quite some time and until reading your opinionwould have considered the Titebond product.John RecinePietenpol air camper, build it like your life depends on it!http://discover.aol.com/memed/aolcom30t ... __________
Subject: Re: Pietenpol-List: Adhesives articleHaving posted the article, I have to say that Gordon's post is really reassuring. The way it turns out a friend of mine is a furniture maker and swearsby the Titebond products, actually suggested on several occasions that I buildusing Titebond III as an alternative to the epoxy's.I resisted the temptation to go cheep and went the West Systems epoxy, which I have been extremely happy working with for several reasons, primarily the mix pump system of a uniform batch every time. After reading the comparison chart I was again tempted to use the Titebond III product on some of the non structural parts for no particular reason other than ease of no having to mix a batch of system 3 epoxy.>From Gordon's perspective and background I made the right choice to resist the temptation of cheep and easy and remain with the tried and true proven system of meter mix and apply. For the record I always leave the project for therecommended set and cure time of 24 hours. Nothing like making a good choice.Gordon thanks again for shedding some much needed light on a topic that I have pondered and read about for quite some time and until reading your opinionwould have considered the Titebond product.John RecinePietenpol air camper, build it like your life depends on it!http://discover.aol.com/memed/aolcom30t ... __________
Pietenpol-List: Re: Adhesive comparison test results
Original Posted By: "MikeD"
[quote="gbowen(at)ptialaska.net"]2) if you have problems with gap filling and/or runouts of the glue, use microballonsto "bulk-up" and then a pinch of cotton flox or silica to eliminate sagof the glue before curing. The flox and silica are thixotropes, kinda likelong fibers under a microscope, this gives thickening without much bulk, andsome added bonding strength.Hope this helpful, and not preachy. Gordon > ---I believe you are suggesting fumed silica versus regular silica filler which wouldn'thelp at all. Fumed silica - for those wondering what the heck it is, onetrade name is Cab-O-Sil - looks a lot like little "burrs", with very high surfacearea to weight ratio, and rocks as a thixotroping agent and structural fillerall in one. Regular silica filler takes a lot to add viscosity, and thenis quite prone to settling unless stabilized with fumed silica. When thixotropingsmall mixes I use fumed silica. Do we really want to add microballoons toa structural airframe adhesive though? I worry some folks will go nuts with itis all.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Adhesive comparison test results
[quote="gbowen(at)ptialaska.net"]2) if you have problems with gap filling and/or runouts of the glue, use microballonsto "bulk-up" and then a pinch of cotton flox or silica to eliminate sagof the glue before curing. The flox and silica are thixotropes, kinda likelong fibers under a microscope, this gives thickening without much bulk, andsome added bonding strength.Hope this helpful, and not preachy. Gordon > ---I believe you are suggesting fumed silica versus regular silica filler which wouldn'thelp at all. Fumed silica - for those wondering what the heck it is, onetrade name is Cab-O-Sil - looks a lot like little "burrs", with very high surfacearea to weight ratio, and rocks as a thixotroping agent and structural fillerall in one. Regular silica filler takes a lot to add viscosity, and thenis quite prone to settling unless stabilized with fumed silica. When thixotropingsmall mixes I use fumed silica. Do we really want to add microballoons toa structural airframe adhesive though? I worry some folks will go nuts with itis all.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Adhesive comparison test results
Original Posted By: "Rick Holland"
[quote="Glenn Thomas"]I guess the redeeming value in the article (although I willread it more closely later) is while there is not an advantage to using slowsetepoxy, there is also no disadvantage (for those of us who used T-88). Is the article written with moisture and common aircraft application in mind?Thanks for sharing the info. It's interesting to read about things like this. Glenn W. ThomasStorrs, CTThere is little reason in theory that faster curing epoxies should offer poorermechanical properties than slower cure. This notion comes from the typical propertiesof consumer adhesive systems, which may use a variety of curative chemistriesto make them do what the label says. Consumer adhesives also tend tobe formulated so that they have a fairly high tolerance for mismatched ratio mixing,which can result in tempering the overall properties in favor of user-friendliness.I have formulated and used epoxy systems with extremely fast curetimes that have equivalent properties to slower set systems. There are a hostof curative chemistries available to the formulater - aromatic amine, aliphaticamine, polyamide, boron trifluoride complexes, yada yada - all with different"raison d'etre" (i.e. better and mechanical properties, reactivity, toxicityandodor considerations, bla bla), and the system can be slowed or hastened bythe selection of more or less reactive curatives within a family and by theuse of curative blends and/or catalysts. Likewise, there are different additivesused in the resin side to achieve certain properties, such as reactive andnon-reactive diluents, rubber-modifiers to increase toughness, structural fillersand thixotroping agents, UV stabilizers, bla bla. Resins straight out of thedrum (like common resins such as Epon 828, Dow 362, others) are okay for laminatingapplications as they are, but for structural adhesives the propertiesare usually improved by intelligent use of various additives.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Fri, 23 Nov 2007 09:25:58 -0700
[quote="Glenn Thomas"]I guess the redeeming value in the article (although I willread it more closely later) is while there is not an advantage to using slowsetepoxy, there is also no disadvantage (for those of us who used T-88). Is the article written with moisture and common aircraft application in mind?Thanks for sharing the info. It's interesting to read about things like this. Glenn W. ThomasStorrs, CTThere is little reason in theory that faster curing epoxies should offer poorermechanical properties than slower cure. This notion comes from the typical propertiesof consumer adhesive systems, which may use a variety of curative chemistriesto make them do what the label says. Consumer adhesives also tend tobe formulated so that they have a fairly high tolerance for mismatched ratio mixing,which can result in tempering the overall properties in favor of user-friendliness.I have formulated and used epoxy systems with extremely fast curetimes that have equivalent properties to slower set systems. There are a hostof curative chemistries available to the formulater - aromatic amine, aliphaticamine, polyamide, boron trifluoride complexes, yada yada - all with different"raison d'etre" (i.e. better and mechanical properties, reactivity, toxicityandodor considerations, bla bla), and the system can be slowed or hastened bythe selection of more or less reactive curatives within a family and by theuse of curative blends and/or catalysts. Likewise, there are different additivesused in the resin side to achieve certain properties, such as reactive andnon-reactive diluents, rubber-modifiers to increase toughness, structural fillersand thixotroping agents, UV stabilizers, bla bla. Resins straight out of thedrum (like common resins such as Epon 828, Dow 362, others) are okay for laminatingapplications as they are, but for structural adhesives the propertiesare usually improved by intelligent use of various additives.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Fri, 23 Nov 2007 09:25:58 -0700
Re: Pietenpol-List: Re: Adhesive comparison test results
Original Posted By: "MikeD"
Having been involved early in my career with the Rutan folks developing suitable laminating epoxies for composite homebuilts, I can tell you a lot of thought went into development of resins for composites homebuilts. Hexcel being the largest worldwide supplier of composite materials for commerical/military aircraft, we had a lot of testing equipment, proven aircraft applicable epoxy formula data bases and wet formulas at our disposal to use developing resins systems for Rutan's hand laminating needs. Have often wondered how much trial and error went into development of epoxies for wood aircraft pre-dating Rutan's demands. Suspect the epoxies used by the early wood builders were simply based on what was available off the shelf, they either worked or didn't. T-88 seemed to be one of those systems that functioned well even if not optimized for the application. As to the question about slow vs fast epoxies, the "5 min. epoxy", used by composite Longeze or Varieze or Cozy homebuilders, this system was never recommened for structural applications, where failure of the bond could compromise the safety of the airplane. All early plans for Rutan designs used our epoxies from Hexcel and only our resins, fast, slow and in the middle gel times . Rutan/Mike Melvil were very picky about their early requirements, they knew we had the testing equipment necessary to do the tests in the lab, saving them trial and error in their workshop or airborne testing by Melvil (world's first private astronaut and maniac test pilot). Testing on fiberglass laminates of "fast"(gel time 30 min or less) vs "slow" (gel times approx. 1 hr-1 1/2 hrs.) formulations always gave poorer mechanical properties with the faster resin systems, using fiberglass as the reinforcment. Heck we still had testing laminate coupons soaking in Avgas for testing 20 years after developing Saf-t-poxy or RAE for Rutan, once per year we'd pull a coupon and do mechanicals to make sure the fuel wasn't destroying the laminate. For the wood homebuilder not sure all this crap this makes a heck of a lot of diff. The structural failure will always be the intra-wood fibers not the bond between the wood fibers and the adhesive. Bulking agents like glass balloons will decrease some mechanical properties of the adhesive layer but the bond would always be stronger than the intra-wood fiber bonds. IF wood homebuilders get good wet-out of the wood and the epoxy formula is not sensitive to the oil/moisture in the wood, their biggest worry won't be bond failure of the wood parts, it' gonna be that big metal bug chopper hanging on the front firewall or the nut behind the control stick.Gordon----- Original Message -----
Having been involved early in my career with the Rutan folks developing suitable laminating epoxies for composite homebuilts, I can tell you a lot of thought went into development of resins for composites homebuilts. Hexcel being the largest worldwide supplier of composite materials for commerical/military aircraft, we had a lot of testing equipment, proven aircraft applicable epoxy formula data bases and wet formulas at our disposal to use developing resins systems for Rutan's hand laminating needs. Have often wondered how much trial and error went into development of epoxies for wood aircraft pre-dating Rutan's demands. Suspect the epoxies used by the early wood builders were simply based on what was available off the shelf, they either worked or didn't. T-88 seemed to be one of those systems that functioned well even if not optimized for the application. As to the question about slow vs fast epoxies, the "5 min. epoxy", used by composite Longeze or Varieze or Cozy homebuilders, this system was never recommened for structural applications, where failure of the bond could compromise the safety of the airplane. All early plans for Rutan designs used our epoxies from Hexcel and only our resins, fast, slow and in the middle gel times . Rutan/Mike Melvil were very picky about their early requirements, they knew we had the testing equipment necessary to do the tests in the lab, saving them trial and error in their workshop or airborne testing by Melvil (world's first private astronaut and maniac test pilot). Testing on fiberglass laminates of "fast"(gel time 30 min or less) vs "slow" (gel times approx. 1 hr-1 1/2 hrs.) formulations always gave poorer mechanical properties with the faster resin systems, using fiberglass as the reinforcment. Heck we still had testing laminate coupons soaking in Avgas for testing 20 years after developing Saf-t-poxy or RAE for Rutan, once per year we'd pull a coupon and do mechanicals to make sure the fuel wasn't destroying the laminate. For the wood homebuilder not sure all this crap this makes a heck of a lot of diff. The structural failure will always be the intra-wood fibers not the bond between the wood fibers and the adhesive. Bulking agents like glass balloons will decrease some mechanical properties of the adhesive layer but the bond would always be stronger than the intra-wood fiber bonds. IF wood homebuilders get good wet-out of the wood and the epoxy formula is not sensitive to the oil/moisture in the wood, their biggest worry won't be bond failure of the wood parts, it' gonna be that big metal bug chopper hanging on the front firewall or the nut behind the control stick.Gordon----- Original Message -----
RE: Pietenpol-List: Re: Adhesives article
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Never use micro for a structural bond. Flox or Cabosil is structural, butnot micro.Brian KrautEngineering Alternatives, Inc.www.engalt.com-----Original Message-----
Never use micro for a structural bond. Flox or Cabosil is structural, butnot micro.Brian KrautEngineering Alternatives, Inc.www.engalt.com-----Original Message-----
Pietenpol-List: Re: Adhesives article
Original Posted By: del magsam
Pietenpol-List: Re: Adhesive comparison test results
Original Posted By: "MikeD"
brian.kraut(at)engalt.com wrote:> Never use micro for a structural bond. Flox or Cabosil is structural, but> not micro.> > Brian Kraut> Engineering Alternatives, Inc.> www.engalt.com> > --Elastomeric microballoons can be considered structural to a degree as they increasetoughness thus reducing possibility of fracture under shock loads, plus theyalso act similarly though not as effectively afaik as rubber modifiers ascrack terminators (akin to drilling small holes a the end of a crack in sheetmaterials). Regular microballoons can be used if the percentage is in check -this of course is limited to cases where the mechanicals still exceed that ofthe substrate, and since that is unknown to the average fellow building an airframe,this use of them is an iffy idea as far as the home builder goes. I agreethat the best rule of thumb is no to use them except in fillers versus structuralapps.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Adhesive comparison test results
brian.kraut(at)engalt.com wrote:> Never use micro for a structural bond. Flox or Cabosil is structural, but> not micro.> > Brian Kraut> Engineering Alternatives, Inc.> www.engalt.com> > --Elastomeric microballoons can be considered structural to a degree as they increasetoughness thus reducing possibility of fracture under shock loads, plus theyalso act similarly though not as effectively afaik as rubber modifiers ascrack terminators (akin to drilling small holes a the end of a crack in sheetmaterials). Regular microballoons can be used if the percentage is in check -this of course is limited to cases where the mechanicals still exceed that ofthe substrate, and since that is unknown to the average fellow building an airframe,this use of them is an iffy idea as far as the home builder goes. I agreethat the best rule of thumb is no to use them except in fillers versus structuralapps.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Adhesive comparison test results
Original Posted By: "Gordon Bowen"
gbowen(at)ptialaska.net wrote:> > > T-88 seemed to be one of those > systems that functioned well even if not optimized for the application. As > to the question about slow vs fast epoxies, the "5 min. epoxy", used by > composite Longeze or Varieze or Cozy homebuilders, this system was never > recommened for structural applications, where failure of the bond could > compromise the safety of the airplane. All early plans for Rutan designs > used our epoxies from Hexcel and only our resins, fast, slow and in the > middle gel times . Rutan/Mike Melvil were very picky about their early > requirements, they knew we had the testing equipment necessary to do the > tests in the lab, saving them trial and error in their workshop or airborne > testing by Melvil (world's first private astronaut and maniac test pilot). > Testing on fiberglass laminates of "fast"(gel time 30 min or less) vs "slow"> (gel times approx. 1 hr-1 1/2 hrs.) formulations always gave poorer > mechanical properties with the faster resin systems, using fiberglass as the> reinforcment. Heck we still had testing laminate coupons soaking in Avgas > for testing 20 years after developing Saf-t-poxy or RAE for Rutan, once per > year we'd pull a coupon and do mechanicals to make sure the fuel wasn't > destroying the laminate. For the wood homebuilder not sure all this crap > this makes a heck of a lot of diff. The structural failure will always be > the intra-wood fibers not the bond between the wood fibers and the adhesive.> Bulking agents like glass balloons will decrease some mechanical properties > of the adhesive layer but the bond would always be stronger than the > intra-wood fiber bonds. IF wood homebuilders get good wet-out of the wood > and the epoxy formula is not sensitive to the oil/moisture in the wood, > their biggest worry won't be bond failure of the wood parts, it' gonna be > that big metal bug chopper hanging on the front firewall or the nut behind > the control stick.> Gordon> ---Bingo. It is substrate failure, not bondline failure that is the issue - or perhapsit would be better to say "should be the issue". As you say, assuming thebond is done right with a sensible choice of epoxy system.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
gbowen(at)ptialaska.net wrote:> > > T-88 seemed to be one of those > systems that functioned well even if not optimized for the application. As > to the question about slow vs fast epoxies, the "5 min. epoxy", used by > composite Longeze or Varieze or Cozy homebuilders, this system was never > recommened for structural applications, where failure of the bond could > compromise the safety of the airplane. All early plans for Rutan designs > used our epoxies from Hexcel and only our resins, fast, slow and in the > middle gel times . Rutan/Mike Melvil were very picky about their early > requirements, they knew we had the testing equipment necessary to do the > tests in the lab, saving them trial and error in their workshop or airborne > testing by Melvil (world's first private astronaut and maniac test pilot). > Testing on fiberglass laminates of "fast"(gel time 30 min or less) vs "slow"> (gel times approx. 1 hr-1 1/2 hrs.) formulations always gave poorer > mechanical properties with the faster resin systems, using fiberglass as the> reinforcment. Heck we still had testing laminate coupons soaking in Avgas > for testing 20 years after developing Saf-t-poxy or RAE for Rutan, once per > year we'd pull a coupon and do mechanicals to make sure the fuel wasn't > destroying the laminate. For the wood homebuilder not sure all this crap > this makes a heck of a lot of diff. The structural failure will always be > the intra-wood fibers not the bond between the wood fibers and the adhesive.> Bulking agents like glass balloons will decrease some mechanical properties > of the adhesive layer but the bond would always be stronger than the > intra-wood fiber bonds. IF wood homebuilders get good wet-out of the wood > and the epoxy formula is not sensitive to the oil/moisture in the wood, > their biggest worry won't be bond failure of the wood parts, it' gonna be > that big metal bug chopper hanging on the front firewall or the nut behind > the control stick.> Gordon> ---Bingo. It is substrate failure, not bondline failure that is the issue - or perhapsit would be better to say "should be the issue". As you say, assuming thebond is done right with a sensible choice of epoxy system.--------Piet-builder-who-hopes-to-be-flying-next-summerRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Re: Pietenpol-List: Re: Adhesive comparison test results
Original Posted By: Matt Dralle
Mike, little off topic for wood laminations and Pietenpols but if you'd like to try a rubber modified laminating resin system (off the shelf), that has some of the best properties for handlaminates try Hexcel's (now HBFuller) 2315. Think Epoxical (now Endurance in St.Paul) making same formula. First it's based on a bis-F epoxy but this epoxy is pre-adducted with Hycar rubber. The liquid rubber precips out when cured and makes a two phase laminate. Our test, before HB Fuller bought-out the Resins group, indicated this was one of our best systems. I used it on my Cozy IV, 60 min gel time, kinda hot exotherm when floxed too thick, but best stuff for laminates that need to resist flex cracking. Scaled Composites used a bunch of it for their contract drones work.Gordon ________________________________________________________________________________Date: Sat, 24 Nov 2007 00:24:59 -0800
Mike, little off topic for wood laminations and Pietenpols but if you'd like to try a rubber modified laminating resin system (off the shelf), that has some of the best properties for handlaminates try Hexcel's (now HBFuller) 2315. Think Epoxical (now Endurance in St.Paul) making same formula. First it's based on a bis-F epoxy but this epoxy is pre-adducted with Hycar rubber. The liquid rubber precips out when cured and makes a two phase laminate. Our test, before HB Fuller bought-out the Resins group, indicated this was one of our best systems. I used it on my Cozy IV, 60 min gel time, kinda hot exotherm when floxed too thick, but best stuff for laminates that need to resist flex cracking. Scaled Composites used a bunch of it for their contract drones work.Gordon ________________________________________________________________________________Date: Sat, 24 Nov 2007 00:24:59 -0800
Pietenpol-List: Wood glues:
Original Posted By: "Gordon Bowen"
Subject: Pietenpol-List: Wood glues:A comment on wood glue that's probably not even related to the topic.I'm using Aeropoxy because a supplier sells it locally. I stopped at theAeropoxy booth at Oshkosh (I never excepted the word "Airventure" toocorporate for a grass roots org.) a couple of years ago and visited withthem. Told them what I was doing, and using, and they wondered why I wasusing that glue instead of another glue they make that is formulatedwith fillers that work better when you may have gaps such as you mayhave in wood. ( I never knew about it ) So speaking of filling agents,there is one co. that is thinking especially for wood. Leon Stefan InKs. Looking out the window at the first snowfall of the winter - Mannn Ihate winter! Bring on Global warming!________________________________________________________________________________
Subject: Pietenpol-List: Wood glues:A comment on wood glue that's probably not even related to the topic.I'm using Aeropoxy because a supplier sells it locally. I stopped at theAeropoxy booth at Oshkosh (I never excepted the word "Airventure" toocorporate for a grass roots org.) a couple of years ago and visited withthem. Told them what I was doing, and using, and they wondered why I wasusing that glue instead of another glue they make that is formulatedwith fillers that work better when you may have gaps such as you mayhave in wood. ( I never knew about it ) So speaking of filling agents,there is one co. that is thinking especially for wood. Leon Stefan InKs. Looking out the window at the first snowfall of the winter - Mannn Ihate winter! Bring on Global warming!________________________________________________________________________________
Re: Pietenpol-List: Wood glues:
Original Posted By: "Leon Stefan"
Leon,Aeropoxy by PTMW co. is one of the epoxy systems that Rutan Aircraft approved for use in his composite designs in approx. 1992. It's been tested for the long haul and resist to aviation fuels. It's good stuff for composites. For your wood laminations, you probably find it a little runny. It's designed to wet out fiberglass laminates. It's a good system and you'll probably see a lot of benefit in using a pinch of flox or Cab-o-sil to thicken it up so it won't run out of vertical glue-ups. In any case, the glue's gonna be stronger than the wood. Here in Alaska's banana belt, weather's been just peachy, if you like dark and rain. Hope Kansas U beats Missu, like to see WVU and Kansas in BCS champs bowl.Gordon----- Original Message -----
Leon,Aeropoxy by PTMW co. is one of the epoxy systems that Rutan Aircraft approved for use in his composite designs in approx. 1992. It's been tested for the long haul and resist to aviation fuels. It's good stuff for composites. For your wood laminations, you probably find it a little runny. It's designed to wet out fiberglass laminates. It's a good system and you'll probably see a lot of benefit in using a pinch of flox or Cab-o-sil to thicken it up so it won't run out of vertical glue-ups. In any case, the glue's gonna be stronger than the wood. Here in Alaska's banana belt, weather's been just peachy, if you like dark and rain. Hope Kansas U beats Missu, like to see WVU and Kansas in BCS champs bowl.Gordon----- Original Message -----