Pietenpol-List: Fabric covering - AFS
Posted: Thu Jun 24, 1999 11:42 am
Original Posted By: Michael King
Hi,I thought I'd pass along an atricle I wrote for our local newsletter (Ialso passed it on to Kitplanes with illusions of grandeur
. I am in theprocess of using it as we speak. One of the Christavia has had his planecovered with the same produce since 1986 and has no complaints at all.They hage a web site at: The web page was developed by none other than the infamous Dick Starks,that crazy member of the Kansas City Dawn Patrol. The Nieuports that theyfly are covered with AFS and they are big proponents of teh system. So far, my wife has covered the tail and, as of Tuesday night, we are nowready to start covering the fuselage. Well, almost, the pre-coverinspection on Tuesday revealed no real problems but I still want to routethe aileron cables before we cover. It's really getting exciting now!KenAFS Fabric Covering.After weeks of reading about numerous covering systems I finally foundmyself in Ennis Montana, the home of Aircraft Finishing Systems (AFS). Itwas midnight on March 6, 1999, when my wife, Rene, and I arrived at theRainbow Valley Motel, having driven 11 hours from Calgary, Alberta. Themotivation for such a trek was twofold. We had already ordered oursupplies for our Christavia MK1 homebuilt and since AFS had scheduled a3-day course over that weekend, we decided to do the course and pick upour supplies in person. Ennis is a beautiful town (population 600) located in SW Montanaapproximately 70 miles north of Yellowstone and situated on Route 287between Butte and Bozeman. The Madison River, featured in the movie "ARiver Runs Through It", runs through the town. During the summer, the townis buzzing with tourists, but in early March, the only tourists comeequipped with their own snowmobiles to take on the snows of the park. Whenwe arrived, there were more snowmobiles in the parking lot than cars andtrucks combined. The night we arrived, we told the very sleepy inn keeper we were heretaking a course for airplane covering and asked if he knew where AFS waslocated. He replied "Paul and Tammy? Yeh, they're out at the airport -just keep south on this road about 5 miles and you can't miss it." I HADasked Tammy for directions before leaving but didn't bother to write themdown. After all, we men don't need no stinkin directions. So, at 8:45 thenext morning we get on the road for our 9:00 class.Sure enough, we found the airport and a large hangar that lookedpromising. As we approached, however, we noticed a distinct lack of freshtire tracks or footprints in the snow. We walked to the hangar to find itquite deserted, but unlocked. Fortunately, there was a phone and a phonebook. I called Tammy and she only laughed a little as she gave medirections to get to their shop - a couple of miles NORTH of the town.As I got in the truck, grumbling, Rene smiled and asked why I didn't getthe directions when I arranged for the course. She knew better than toexpect a response from that one.A Little BackgroundAFS was started a year and a half ago by Paul and Tammy Yedinak after a 15year association with the Blue River 7600 process. Blue River Aircraftacquired the Eonex covering process in the early 80's. The originalprocess employed Ceconite fabric attached with a two-part cement/activatorgluing process and sealed with the 7601 filler coat, an early version ofCecoFill. A two-part epoxy paint was used to finish the fabric. In 1991,a one part, water soluble cement called CecoBond was developed, tested andadded to the 7600 process replacing the old cement. After trying numerous covering systems, Paul and Tammy first used the BlueRiver 7600 process to cover a Super Cub in Miles City, Montana in 1982. Bythe early 90's they were fielding Blue River Aircraft technical supportcalls, taking orders, troubleshooting and performing R&D. In April, 1997Tammy formed a small company called Aircraft Finishing Systems (AFS) andadded an 800 line to more formally handle the Blue River support calls. Six months later, AFS took over the Blue River line of fabric products andbecame a Ceconite distributor. At about the same time, AFS added theirown water borne epoxy primers and top coats to the product line tocomplete their fabric covering system. In its current form, the AFS covering process consists of the primer forthe base structure (yet unnamed), the glue used to adhere the fabric tothe structure (CecoBond), the combination fill coat and UV block(CecoFill), and the top coats. Ceconite is the fabric called for in theSTC covering this process, but the system will work with competitivefabrics as well. Rounding out the product line are the all-importanttraining seminars that AFS offers. There will soon be an instructionalvideo available which may actually include our class. I'll have to get myspeech ready "I'd like to thank all the little people who helped me winthis Oscar for 'Best Supporting Actor in an Aviation How-To Video' ....." Over the years since first using the Blue River 7600 process, they haverebuilt and covered numerous aircraft including several PA-12's as well asan SNJ trainer, the Navy version of the AT-6. They are currently coveringa Beech Staggerwing and just finished a Scout tow plane. Paul is an AI andtaught Tammy the basics of covering aircraft. From there, she perfectedthe technique and does beautiful detail work. This was evident in the lastplane they did using all straight tapes. Tammy was not entirely pleasedwith the end result and called the client to tell him that if he wasn'tsatisfied, they could do it again. The owner came in and was more thanpleased with the finish and commenting that "It's just a tow plane". Thisbecame the buzz phrase for the weekend. Whenever we made a mistake or didsomething that wasn't to Tammy's standards, we'd come back with " Don'tworry, it's just a tow plane" Back to ClassThe class itself was quite unique. In addition to Rene and I, there wasanother couple, Mike and his fianc, Tracy. They are building an Avid Flyerin Butte, about one and a half hours away. This was the first time AFS hadany women taking the class. The six of us clicked together quite well andended up having a great time.Working in our pairs, we started with some mock elevator control surfacesthat Paul had welded up for the class. The first step was to add themultipurpose tape along each of the "ribs". This prevents chafing of thefabric when the rib stitches are applied. This tape is a self adhesive,woven tape similar to the tape used on hockey sticks. Then out came the glue. The CecoBond glue is similar to contact cement inthe way that it works. It starts out as a liquid and sets up into aflexible but incredibly strong rubber-like substance. It was painted onthe perimeter of the surface using 1" brushes. One of the neat tricks theyshowed us was to glue the bottom half of a small (2-4 oz) paper cup to apaper plate. Another cup is filled with glue and placed in the half cup.This forms a kind of "cup and saucer" rig that can be placed anywhere onthe fabric with little fear of it tipping over. The fabric is laid on the frame once the glue becomes tacky, then moreglue is forced down through the fabric. This is where a little practicecomes in - using too much glue can cause problems in the later stages ofcovering with the fabric "dimpling" on the frame and having to be pulledup later. The glue is also the sealer, which means that forcing more glueinto that section of fabric becomes impossible and the adhesion iscompromised. Tammy and Paul have discovered that dry glue can be removedfrom irons, scissors and fingers with an industrial gum eraser. Theseerasers can be found at lumberyards where they are used for cleaningsanding disks. It is also useful to remove excess surface glue from thefabric once it has dried. Since the glue is water soluble, water willalso help in the clean up while the glue is still wet. When we finished applying the fabric, it was shrunk using an iron set toabout 270 degrees. This pre-shrinking stage takes the slack from thefabric. We then started on the other side of our surface using the sameprocedure as above. This side is tricky as well because you have to try toapply the glue and fabric without interfering with the first side as wellas worrying about not letting the fabric dimple. We ended up having tolive with a couple of dimples as yours truly got a little carried awaywith slopping on the glue. Oh well, it's just a tow-plane!The other interesting part was forming the fabric around the curvedcorners of the control surface. Tammy gave us two choices - the first wasto cut the overlap into small strips and let them overlap each other asyou came around the curve. The second, and more desirable, is to shrinkthe fabric with an iron around the curve. This was fairly easy to do withthe 1" overlap on the main sheets of fabric. However, when we startedtaping, Tammy suggested we use a 3" tape to form around the corner as aworst case scenario. We ironed those tapes for what seemed like hours.Tracy ended up being the envy of the group as her corner of the controlwas amazingly smooth and tight. Rene and I ended up with some wrinkles byusing too much heat at the beginning. While Tammy was out of the room for a couple of minutes, Paul suggested analternative method for getting out those wrinkles. He snuck out andappeared a moment later, menacingly brandishing a heat gun. With an evilgrin he approached the control surface, fire belching from the muzzle ofthe gun. Just as he was about to hit our surface with a couple of thousandBTU's, Tammy walked through the door. She LOOKED at him and he looked ather like a kid who has just been caught with his hand in the cookie jar. He tried to protest, using the argument that "if they are going to do itwrong, they should at least know how to do it right". Tammy was unmoved. He did admit that using a heat gun was a definite no-no, but after all,this was only a tow plane. But before we got to the taping, we had to try our hand at rib stitching. Despite the stigma that has arisen around how difficult it is torib-stitch, it is actually fairly easy. Regardless of how light your planeis, I think that it is imperative that there be something more than a gluejoint holding the fabric in place whether it be screws, rivets, wire orlacing. If you do decide to rib-stitch, the flat cord seems to work a lotnicer than the round. We ended up adding a second layer of reinforcementtape over the round cord stitches after they were done to preventaccidentally sanding through the stitch in the finishing process. While working on the Staggerwing, Paul and Tammy came across a rather easystitch in the maintenance manual. Affectionately called the Staggerwingstitch, it is a lot easier than commonly used seine stitch.We also added inspection rings and control fairleads to our control. Therings are glued to the surface and covered with a patch. Fairleads, usedwhere control cables or support wires pass through the fabric, were cutfrom a synthetic fabric material and simply glued to the surface.Fiberglass can also be used and covered with a Ceconite patch to make asmoother transition. The next step is sealing the fabric, which is done by using thinned (fivepercent distilled water) CecoBond, applied with a foam brush. A very thincoating is all that's necessary. Rene was the queen of coating getting aperfect even finish. As a man, I must say that it's far more masculine tohave that light blue color rather than the girlie pink color that you endup with using the PolyFiber process. Finally, it was on to the spray shop. Paul has set up the second bay oftheir office area with a small, folding spray booth. Since the materialsare non-toxic, all that's really needed is a charcoal mask. However, tokeep down the dust level, he also suggests using a small, filtereddischarge fan. Usually, these fans would be vented outside, but in thisapplication it's just used to filter the paint dust out of the air anddischarges back into the room.Since Paul had recommended an HVLP spray paint gun, I shopped around priorto our trip and found that most of them cost more than my compressor! Then - success - I stumbled across a Star 950 HVLP gun at House of Toolshere in Calgary that was only $150 CDN. As I was unsure of how it wouldwork, I decided to buy it and take it with me for the course.In Paul's expert hands, the gun was all set up in less than 15 minutes. The verdict was that it was more than adequate to do the job. The moreexpensive guns do atomize the paint better at a lower pressure. However,similar results were also achievable with the Star gun using slightlyhigher pressures. For a professional, this would certainly be an issue asmore overspray is generated. However, for an amateur painting one plane,it is ideal.In the paint booth, the CecoFill is sprayed on first. It's a dark gray,high solids coating that both fills the weave as well as provides a UVbarrier. Due to the thickness of CecoFill, Paul suggests using a filtermade from an insect screen (like in your windows at home) to strain itinto the paint gun. Four mist coats were sprayed in a crisscrossed pattern(vertically for one coat, horizontally for the next). Following this, thecontrol was sanded with 260-grit sandpaper to get rid of anyimperfections. This process was repeated twice before a final sanding with400-grit paper. Finally - the moment of truth - applying the topcoats. This is a fairlyconventional step and anyone with experience with paint guns will becomfortable with using the supplied paints. When we the process wascomplete and dry, the fabric was ripped of the frame to take home as atrophy. Obviously, this is one step you may want to skip when coveringyour own plane. GraduationIn all, we spent about 24 hours in the class over two and a half days. Itwas definitely the most enjoyable class I have ever attended. I didn't getany detention for talking in class or for taunting Paul and his heat gun. Even if you don't plan on using their system, you can't go wrong withtaking their course. The products they sell, however, are worthconsidering especially if you want to avoid the harmful solvents containedin most paints. Personally, because we have an attached garage, we wouldhave to rent space to cover the airplane because of the possible toxins. Their products are as good as any other products currently available and Iwould recommend their system without hesitation. Don't let the size of theoperation fool you. The Yedinaks are very professional and capable tohandle your covering needs. In fact, the small size makes them quiterefreshing to deal with. They know exactly what we are building and Idon't have to explain my project every time I call for support. They areeven reachable on Saturdays if you get in a bind. I will do a follow uparticle when we start covering the Christavia, which had better startquickly as Rene is already eyeing things around the house to startcovering. ________________________________________________________________________________
Hi,I thought I'd pass along an atricle I wrote for our local newsletter (Ialso passed it on to Kitplanes with illusions of grandeur
. I am in theprocess of using it as we speak. One of the Christavia has had his planecovered with the same produce since 1986 and has no complaints at all.They hage a web site at: The web page was developed by none other than the infamous Dick Starks,that crazy member of the Kansas City Dawn Patrol. The Nieuports that theyfly are covered with AFS and they are big proponents of teh system. So far, my wife has covered the tail and, as of Tuesday night, we are nowready to start covering the fuselage. Well, almost, the pre-coverinspection on Tuesday revealed no real problems but I still want to routethe aileron cables before we cover. It's really getting exciting now!KenAFS Fabric Covering.After weeks of reading about numerous covering systems I finally foundmyself in Ennis Montana, the home of Aircraft Finishing Systems (AFS). Itwas midnight on March 6, 1999, when my wife, Rene, and I arrived at theRainbow Valley Motel, having driven 11 hours from Calgary, Alberta. Themotivation for such a trek was twofold. We had already ordered oursupplies for our Christavia MK1 homebuilt and since AFS had scheduled a3-day course over that weekend, we decided to do the course and pick upour supplies in person. Ennis is a beautiful town (population 600) located in SW Montanaapproximately 70 miles north of Yellowstone and situated on Route 287between Butte and Bozeman. The Madison River, featured in the movie "ARiver Runs Through It", runs through the town. During the summer, the townis buzzing with tourists, but in early March, the only tourists comeequipped with their own snowmobiles to take on the snows of the park. Whenwe arrived, there were more snowmobiles in the parking lot than cars andtrucks combined. The night we arrived, we told the very sleepy inn keeper we were heretaking a course for airplane covering and asked if he knew where AFS waslocated. He replied "Paul and Tammy? Yeh, they're out at the airport -just keep south on this road about 5 miles and you can't miss it." I HADasked Tammy for directions before leaving but didn't bother to write themdown. After all, we men don't need no stinkin directions. So, at 8:45 thenext morning we get on the road for our 9:00 class.Sure enough, we found the airport and a large hangar that lookedpromising. As we approached, however, we noticed a distinct lack of freshtire tracks or footprints in the snow. We walked to the hangar to find itquite deserted, but unlocked. Fortunately, there was a phone and a phonebook. I called Tammy and she only laughed a little as she gave medirections to get to their shop - a couple of miles NORTH of the town.As I got in the truck, grumbling, Rene smiled and asked why I didn't getthe directions when I arranged for the course. She knew better than toexpect a response from that one.A Little BackgroundAFS was started a year and a half ago by Paul and Tammy Yedinak after a 15year association with the Blue River 7600 process. Blue River Aircraftacquired the Eonex covering process in the early 80's. The originalprocess employed Ceconite fabric attached with a two-part cement/activatorgluing process and sealed with the 7601 filler coat, an early version ofCecoFill. A two-part epoxy paint was used to finish the fabric. In 1991,a one part, water soluble cement called CecoBond was developed, tested andadded to the 7600 process replacing the old cement. After trying numerous covering systems, Paul and Tammy first used the BlueRiver 7600 process to cover a Super Cub in Miles City, Montana in 1982. Bythe early 90's they were fielding Blue River Aircraft technical supportcalls, taking orders, troubleshooting and performing R&D. In April, 1997Tammy formed a small company called Aircraft Finishing Systems (AFS) andadded an 800 line to more formally handle the Blue River support calls. Six months later, AFS took over the Blue River line of fabric products andbecame a Ceconite distributor. At about the same time, AFS added theirown water borne epoxy primers and top coats to the product line tocomplete their fabric covering system. In its current form, the AFS covering process consists of the primer forthe base structure (yet unnamed), the glue used to adhere the fabric tothe structure (CecoBond), the combination fill coat and UV block(CecoFill), and the top coats. Ceconite is the fabric called for in theSTC covering this process, but the system will work with competitivefabrics as well. Rounding out the product line are the all-importanttraining seminars that AFS offers. There will soon be an instructionalvideo available which may actually include our class. I'll have to get myspeech ready "I'd like to thank all the little people who helped me winthis Oscar for 'Best Supporting Actor in an Aviation How-To Video' ....." Over the years since first using the Blue River 7600 process, they haverebuilt and covered numerous aircraft including several PA-12's as well asan SNJ trainer, the Navy version of the AT-6. They are currently coveringa Beech Staggerwing and just finished a Scout tow plane. Paul is an AI andtaught Tammy the basics of covering aircraft. From there, she perfectedthe technique and does beautiful detail work. This was evident in the lastplane they did using all straight tapes. Tammy was not entirely pleasedwith the end result and called the client to tell him that if he wasn'tsatisfied, they could do it again. The owner came in and was more thanpleased with the finish and commenting that "It's just a tow plane". Thisbecame the buzz phrase for the weekend. Whenever we made a mistake or didsomething that wasn't to Tammy's standards, we'd come back with " Don'tworry, it's just a tow plane" Back to ClassThe class itself was quite unique. In addition to Rene and I, there wasanother couple, Mike and his fianc, Tracy. They are building an Avid Flyerin Butte, about one and a half hours away. This was the first time AFS hadany women taking the class. The six of us clicked together quite well andended up having a great time.Working in our pairs, we started with some mock elevator control surfacesthat Paul had welded up for the class. The first step was to add themultipurpose tape along each of the "ribs". This prevents chafing of thefabric when the rib stitches are applied. This tape is a self adhesive,woven tape similar to the tape used on hockey sticks. Then out came the glue. The CecoBond glue is similar to contact cement inthe way that it works. It starts out as a liquid and sets up into aflexible but incredibly strong rubber-like substance. It was painted onthe perimeter of the surface using 1" brushes. One of the neat tricks theyshowed us was to glue the bottom half of a small (2-4 oz) paper cup to apaper plate. Another cup is filled with glue and placed in the half cup.This forms a kind of "cup and saucer" rig that can be placed anywhere onthe fabric with little fear of it tipping over. The fabric is laid on the frame once the glue becomes tacky, then moreglue is forced down through the fabric. This is where a little practicecomes in - using too much glue can cause problems in the later stages ofcovering with the fabric "dimpling" on the frame and having to be pulledup later. The glue is also the sealer, which means that forcing more glueinto that section of fabric becomes impossible and the adhesion iscompromised. Tammy and Paul have discovered that dry glue can be removedfrom irons, scissors and fingers with an industrial gum eraser. Theseerasers can be found at lumberyards where they are used for cleaningsanding disks. It is also useful to remove excess surface glue from thefabric once it has dried. Since the glue is water soluble, water willalso help in the clean up while the glue is still wet. When we finished applying the fabric, it was shrunk using an iron set toabout 270 degrees. This pre-shrinking stage takes the slack from thefabric. We then started on the other side of our surface using the sameprocedure as above. This side is tricky as well because you have to try toapply the glue and fabric without interfering with the first side as wellas worrying about not letting the fabric dimple. We ended up having tolive with a couple of dimples as yours truly got a little carried awaywith slopping on the glue. Oh well, it's just a tow-plane!The other interesting part was forming the fabric around the curvedcorners of the control surface. Tammy gave us two choices - the first wasto cut the overlap into small strips and let them overlap each other asyou came around the curve. The second, and more desirable, is to shrinkthe fabric with an iron around the curve. This was fairly easy to do withthe 1" overlap on the main sheets of fabric. However, when we startedtaping, Tammy suggested we use a 3" tape to form around the corner as aworst case scenario. We ironed those tapes for what seemed like hours.Tracy ended up being the envy of the group as her corner of the controlwas amazingly smooth and tight. Rene and I ended up with some wrinkles byusing too much heat at the beginning. While Tammy was out of the room for a couple of minutes, Paul suggested analternative method for getting out those wrinkles. He snuck out andappeared a moment later, menacingly brandishing a heat gun. With an evilgrin he approached the control surface, fire belching from the muzzle ofthe gun. Just as he was about to hit our surface with a couple of thousandBTU's, Tammy walked through the door. She LOOKED at him and he looked ather like a kid who has just been caught with his hand in the cookie jar. He tried to protest, using the argument that "if they are going to do itwrong, they should at least know how to do it right". Tammy was unmoved. He did admit that using a heat gun was a definite no-no, but after all,this was only a tow plane. But before we got to the taping, we had to try our hand at rib stitching. Despite the stigma that has arisen around how difficult it is torib-stitch, it is actually fairly easy. Regardless of how light your planeis, I think that it is imperative that there be something more than a gluejoint holding the fabric in place whether it be screws, rivets, wire orlacing. If you do decide to rib-stitch, the flat cord seems to work a lotnicer than the round. We ended up adding a second layer of reinforcementtape over the round cord stitches after they were done to preventaccidentally sanding through the stitch in the finishing process. While working on the Staggerwing, Paul and Tammy came across a rather easystitch in the maintenance manual. Affectionately called the Staggerwingstitch, it is a lot easier than commonly used seine stitch.We also added inspection rings and control fairleads to our control. Therings are glued to the surface and covered with a patch. Fairleads, usedwhere control cables or support wires pass through the fabric, were cutfrom a synthetic fabric material and simply glued to the surface.Fiberglass can also be used and covered with a Ceconite patch to make asmoother transition. The next step is sealing the fabric, which is done by using thinned (fivepercent distilled water) CecoBond, applied with a foam brush. A very thincoating is all that's necessary. Rene was the queen of coating getting aperfect even finish. As a man, I must say that it's far more masculine tohave that light blue color rather than the girlie pink color that you endup with using the PolyFiber process. Finally, it was on to the spray shop. Paul has set up the second bay oftheir office area with a small, folding spray booth. Since the materialsare non-toxic, all that's really needed is a charcoal mask. However, tokeep down the dust level, he also suggests using a small, filtereddischarge fan. Usually, these fans would be vented outside, but in thisapplication it's just used to filter the paint dust out of the air anddischarges back into the room.Since Paul had recommended an HVLP spray paint gun, I shopped around priorto our trip and found that most of them cost more than my compressor! Then - success - I stumbled across a Star 950 HVLP gun at House of Toolshere in Calgary that was only $150 CDN. As I was unsure of how it wouldwork, I decided to buy it and take it with me for the course.In Paul's expert hands, the gun was all set up in less than 15 minutes. The verdict was that it was more than adequate to do the job. The moreexpensive guns do atomize the paint better at a lower pressure. However,similar results were also achievable with the Star gun using slightlyhigher pressures. For a professional, this would certainly be an issue asmore overspray is generated. However, for an amateur painting one plane,it is ideal.In the paint booth, the CecoFill is sprayed on first. It's a dark gray,high solids coating that both fills the weave as well as provides a UVbarrier. Due to the thickness of CecoFill, Paul suggests using a filtermade from an insect screen (like in your windows at home) to strain itinto the paint gun. Four mist coats were sprayed in a crisscrossed pattern(vertically for one coat, horizontally for the next). Following this, thecontrol was sanded with 260-grit sandpaper to get rid of anyimperfections. This process was repeated twice before a final sanding with400-grit paper. Finally - the moment of truth - applying the topcoats. This is a fairlyconventional step and anyone with experience with paint guns will becomfortable with using the supplied paints. When we the process wascomplete and dry, the fabric was ripped of the frame to take home as atrophy. Obviously, this is one step you may want to skip when coveringyour own plane. GraduationIn all, we spent about 24 hours in the class over two and a half days. Itwas definitely the most enjoyable class I have ever attended. I didn't getany detention for talking in class or for taunting Paul and his heat gun. Even if you don't plan on using their system, you can't go wrong withtaking their course. The products they sell, however, are worthconsidering especially if you want to avoid the harmful solvents containedin most paints. Personally, because we have an attached garage, we wouldhave to rent space to cover the airplane because of the possible toxins. Their products are as good as any other products currently available and Iwould recommend their system without hesitation. Don't let the size of theoperation fool you. The Yedinaks are very professional and capable tohandle your covering needs. In fact, the small size makes them quiterefreshing to deal with. They know exactly what we are building and Idon't have to explain my project every time I call for support. They areeven reachable on Saturdays if you get in a bind. I will do a follow uparticle when we start covering the Christavia, which had better startquickly as Rene is already eyeing things around the house to startcovering. ________________________________________________________________________________