sealing seams with koverall
11-14-2009, 09:17 PM
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sealing seams with koverall
ok .I started covering my plane using koverall.I applied stix on the frame and let it dry and put the koverall on and sealed the edges but theres fuzz on the trailing edges.is this common or did I screw it up.if I apply clear dope to the fabric and it dries can I lightly sand that fuzz off.what technquies do you use when you cover with this fabric.I only did the elevator so far so if I have to rip it off and start ove #$%^&*& I will do it..
11-14-2009, 09:41 PM
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RE: sealing seams with koverall
I've covered several planes with Koverall and ran into the same issue. On the last plane I got tired of trying to figure it out myself and sought out the expert help of a club member. This was his method, and I can say it worked very well when I tried it.
Example covering a wing:
-3 coats thinned nitrate dope on all bare balsa, top and bottom of wing
-1 coat Stix-it around the edges, top and bottom
-put fabric on bottom of wing with an iron, leaving a bit extra hanging over the edges
-2 coats nitrate dope around the edges, basically where you put the Stix-it
-now cut the fabric where it over hangs, it will cut very cleanly without the fuzz after the 2 coats of dope
-if any edges are not stuck down to the wood, apply a bit of thinned dope to soften up the fabric and rub it down with your finger
-put Stix-it on the fabric where the top will cover the bottom
-put the fabric on with the iron, and apply 2-3 coats dope around the edges
-cut off excess fabric after the dope dries
-heat shrink the fabric in any open bays and where there are any wrinkes
-apply dope to the whole thing
As far as what you've done already, yes you can sand off the fuzz after one or two coats of dope. It doesn't sand off as easily or cleanly as fiberglass and you have to be more careful not to sand through nearby areas. If you use the method above you won't get the fuzz to start with. Good luck, post some pics.
Example covering a wing:
-3 coats thinned nitrate dope on all bare balsa, top and bottom of wing
-1 coat Stix-it around the edges, top and bottom
-put fabric on bottom of wing with an iron, leaving a bit extra hanging over the edges
-2 coats nitrate dope around the edges, basically where you put the Stix-it
-now cut the fabric where it over hangs, it will cut very cleanly without the fuzz after the 2 coats of dope
-if any edges are not stuck down to the wood, apply a bit of thinned dope to soften up the fabric and rub it down with your finger
-put Stix-it on the fabric where the top will cover the bottom
-put the fabric on with the iron, and apply 2-3 coats dope around the edges
-cut off excess fabric after the dope dries
-heat shrink the fabric in any open bays and where there are any wrinkes
-apply dope to the whole thing
As far as what you've done already, yes you can sand off the fuzz after one or two coats of dope. It doesn't sand off as easily or cleanly as fiberglass and you have to be more careful not to sand through nearby areas. If you use the method above you won't get the fuzz to start with. Good luck, post some pics.
11-15-2009, 07:10 AM
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RE: sealing seams with koverall
I agree .and when I get to covering the main body your procedure is the best way.and next time I think I'll go with solartex..but I think with the fabric ahered and the dope brushed on and dry the trimmed ends will be easier to seal and lightly sand its been years since I painted an airplane but I am tired of monokote too espescially on a big plane.
11-15-2009, 10:05 AM
#6
RE: sealing seams with koverall
I use Nitrate dope exclusively to attach the Koverall. 3 coats on the bare wood, sanding in between coats. Apply the Koverall and attach with Nitrate dope. Overlap Koverall over itself and stick down with dope. Once a wing (for instance) is completely covered I hit the seams hard with dope. For example:
Paint dope on all seams with a brush.
Brush the entire framework with dope.
Go back over the seams again with dope.
When I am ready to spray the dope, I will spray the seams first, then the top/bottom of the wing, then revisit the seams again. You get the idea.
I always sand in between coats, more so on the seams. After a couple of coats and sanding, the fuzz goes away. Several coats later and the seam itself will disappear. Been using this method for nearly 20 years. Go easy on the sanding. A "lick and a promise" is the order of the day here. 220 grit, folded over itself twice, is plenty. Go REAL easy on open areas and places with no seams.
After the Nitrate dope has been applied (3 coats sprayed, maybe 4), let it dry until you can't smell it anymore. Then you can top coat with anything you like.
Little tip for you: When you are using a dope brush, DON"T CLEAN IT. Let it dry full of dope and get rock hard. The next time you need to use it, let it soak in either dope or lacquer thinner and it will be like new in about 10 minutes. I only clean my dope brush once; after I am completely done using it.
Paint dope on all seams with a brush.
Brush the entire framework with dope.
Go back over the seams again with dope.
When I am ready to spray the dope, I will spray the seams first, then the top/bottom of the wing, then revisit the seams again. You get the idea.
I always sand in between coats, more so on the seams. After a couple of coats and sanding, the fuzz goes away. Several coats later and the seam itself will disappear. Been using this method for nearly 20 years. Go easy on the sanding. A "lick and a promise" is the order of the day here. 220 grit, folded over itself twice, is plenty. Go REAL easy on open areas and places with no seams.
After the Nitrate dope has been applied (3 coats sprayed, maybe 4), let it dry until you can't smell it anymore. Then you can top coat with anything you like.
Little tip for you: When you are using a dope brush, DON"T CLEAN IT. Let it dry full of dope and get rock hard. The next time you need to use it, let it soak in either dope or lacquer thinner and it will be like new in about 10 minutes. I only clean my dope brush once; after I am completely done using it.
11-15-2009, 10:24 AM
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RE: sealing seams with koverall
your advise is timely.I am on my way to a local hardware store to load up on sandpaper and a few more dope brushes.I wondered if I soaked it in the dope if it would soften.thanks.and I just applied a third coat and am letting it dry completely or as you suggest till the wonderful smell is gone. have you used sanding sealer at all to fill the weave. the fuzz is no longer a concern.but I learned very fast to go easy on the sanding but it certainly works after a couple coats of dope.and I am following the other advise to leave the fabric overlapping.and I dug out some new razor blades as they dull fast. my wife gave me a couple extra rotary cutters to cut the fabric .they are great and so far I only have cut myself once!
It is a long process but when I finish my spacewalker it will look sharp.I guess when I was younger I simply didnt have the time for finishing but now I am more patient and just need to understand the process better.you help and everyone else has helped alot..
It is a long process but when I finish my spacewalker it will look sharp.I guess when I was younger I simply didnt have the time for finishing but now I am more patient and just need to understand the process better.you help and everyone else has helped alot..
11-15-2009, 10:26 AM
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RE: sealing seams with koverall
Don't give up on Koverall just yet. Like film covering, it takes a bit of practice to get it right (ok, maybe more so) but the results are well worth it. I don't have experience with solartex, but I can't imagine a covering more durable than koverall! Like carlgrover, I only use Nitrate dope for attaching the Koverall. I tried stix it on the first plane that I covered but found it to be more trouble than it was worth. Seems like it would be easier but it actually causes more problems. For example, those fuzzies you are referring to are usually caused by the stix it. When you iron the covering down some of the stix it seeps through the weave getting on your iron. Then the sticky iron pulls the already frayed edges of the fabric causing the weave to unravel. When you dope the covering down, work the dope past where you plan to trim the fabric off. This will harden the fabric and it will cut cleanly with a single edge razor blade.
Another tip: shrink the covering before you trim the edges. That way if the seems pulls away, you have some excess you can stick down to cover the seem.
Brian
Another tip: shrink the covering before you trim the edges. That way if the seems pulls away, you have some excess you can stick down to cover the seem.
Brian
11-15-2009, 01:08 PM
#9
RE: sealing seams with koverall
You can soak your brush in dope but I prefer thinner because it softens quicker.
Unless you are going to top coat with butyrate dope I would wait a couple of weeks, maybe 3 prior to top coating (I'm assuming that you have sprayed the third coat of nitrate). If you don't wait long enough, the nitrate will bubble up thru your paint.
I tried sanding sealer once. Never again. Your finish will look great with 3 coats of dope and a paint top coat.
Fabric is hard on razors. Plan on changing out often. I have sanded the covering off sometimes but I wouldn't recommend it. It leaves the edges looking rough then it's more work to smooth it all out.
Post some pics of the final product. I have found that a Koverall/dope finish is much easier to do than monokote. Maybe more work, but that Koverall is very easy to work around corners. It will get easier for you as you do more planes with it.
Unless you are going to top coat with butyrate dope I would wait a couple of weeks, maybe 3 prior to top coating (I'm assuming that you have sprayed the third coat of nitrate). If you don't wait long enough, the nitrate will bubble up thru your paint.
I tried sanding sealer once. Never again. Your finish will look great with 3 coats of dope and a paint top coat.
Fabric is hard on razors. Plan on changing out often. I have sanded the covering off sometimes but I wouldn't recommend it. It leaves the edges looking rough then it's more work to smooth it all out.
Post some pics of the final product. I have found that a Koverall/dope finish is much easier to do than monokote. Maybe more work, but that Koverall is very easy to work around corners. It will get easier for you as you do more planes with it.
11-16-2009, 07:22 PM
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RE: sealing seams with koverall
Hey Carl, nice info in your posting. I used koverall and Sig Stix-it on my last model and i want to go fabric again. I much prefer the look to monokote. Could you enlighten me on a couple of things on your technique?
BTW, I will spray the koverall with hair spray before cutting to make a clean cut to keep the fuzzies way down.
Question 1. When do you start the shrink process? And how much at a time do you shrink?
I stuck the coverall at the seams everywhere and then sharnk the coverall down to taught. I then brushed on Minwax Polycrylic. 3 coats, not thinned. After that I would sand after each coat of Poly. I then primed with an auto rattle can primer. I had the local auto parts store mix me some paint and it went on well with my Lowes compressor/sprayer. I thinned the paint by about 25%.
Question 2. Will you switch to a fabric covering with the adhesive already applied? If so, which one? I think I would like to try that next time myself. But to be honest, I do not think the seams are very hard when you use Polycrylic as the sand smooth easily. The thing I found most difficult was pulling out and shrinking out the wrinkles in the curved areas. That might not be any less difficult with a pre-adhesive applied fabric.
BTW I will be starting a build thread for my new Tiger 60 when I get it. My B-day is in 2 weeks and I have let it be know I can get the engine/radio for Xmas. Just get me the plane now so I can start building. Looking forward to any advice from anyone and everyone.
Hey Carl..... Roll Tide Roll
BTW, I will spray the koverall with hair spray before cutting to make a clean cut to keep the fuzzies way down.
Question 1. When do you start the shrink process? And how much at a time do you shrink?
I stuck the coverall at the seams everywhere and then sharnk the coverall down to taught. I then brushed on Minwax Polycrylic. 3 coats, not thinned. After that I would sand after each coat of Poly. I then primed with an auto rattle can primer. I had the local auto parts store mix me some paint and it went on well with my Lowes compressor/sprayer. I thinned the paint by about 25%.
Question 2. Will you switch to a fabric covering with the adhesive already applied? If so, which one? I think I would like to try that next time myself. But to be honest, I do not think the seams are very hard when you use Polycrylic as the sand smooth easily. The thing I found most difficult was pulling out and shrinking out the wrinkles in the curved areas. That might not be any less difficult with a pre-adhesive applied fabric.
BTW I will be starting a build thread for my new Tiger 60 when I get it. My B-day is in 2 weeks and I have let it be know I can get the engine/radio for Xmas. Just get me the plane now so I can start building. Looking forward to any advice from anyone and everyone.
Hey Carl..... Roll Tide Roll
11-16-2009, 08:30 PM
#12
RE: sealing seams with koverall
I prefer to stick the Koverall down with dope,
I have used PolyC for filling the weave and hiding the seams and it works very well also. The PolyC has to dry good before it will sand without balling up. If the finish is done properly all the seams will all but dissapear. I have used Latex paint as well as Krylon spray cans with good results over the Koverall. My 1st plane covered with Koverall was my 1/4 Cub and it is 5 years old and still looks new. No more plastic film being used on my planes. Here are a few of my planes covered with Koverall.
Later!!
Anthony
I have used PolyC for filling the weave and hiding the seams and it works very well also. The PolyC has to dry good before it will sand without balling up. If the finish is done properly all the seams will all but dissapear. I have used Latex paint as well as Krylon spray cans with good results over the Koverall. My 1st plane covered with Koverall was my 1/4 Cub and it is 5 years old and still looks new. No more plastic film being used on my planes. Here are a few of my planes covered with Koverall.
Later!!
Anthony
11-16-2009, 11:09 PM
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RE: sealing seams with koverall
ORIGINAL: WacoNut
I prefer to stick the Koverall down with dope,
I have used PolyC for filling the weave and hiding the seams and it works very well also. The PolyC has to dry good before it will sand without balling up. If the finish is done properly all the seams will all but dissapear. I have used Latex paint as well as Krylon spray cans with good results over the Koverall. My 1st plane covered with Koverall was my 1/4 Cub and it is 5 years old and still looks new. No more plastic film being used on my planes. Here are a few of my planes covered with Koverall.
Later!!
Anthony
I prefer to stick the Koverall down with dope,
I have used PolyC for filling the weave and hiding the seams and it works very well also. The PolyC has to dry good before it will sand without balling up. If the finish is done properly all the seams will all but dissapear. I have used Latex paint as well as Krylon spray cans with good results over the Koverall. My 1st plane covered with Koverall was my 1/4 Cub and it is 5 years old and still looks new. No more plastic film being used on my planes. Here are a few of my planes covered with Koverall.
Later!!
Anthony
Chuck
11-17-2009, 04:48 AM
#14
RE: sealing seams with koverall
Properly applied Minnwax PolyCryllic should be sandable within a few hours. If you have trouble with it balling up on your sand paper, try applying lighter coats.
Solartex has an adhesive backing, but for insurance, I spray the airframe with Aqua Net hairspray, for added security. I have not used Koverall, but I can say that Solartex is easier to apply than Super Coverite.
I've had no problems with the seams, using Solartex.
Solartex has an adhesive backing, but for insurance, I spray the airframe with Aqua Net hairspray, for added security. I have not used Koverall, but I can say that Solartex is easier to apply than Super Coverite.
I've had no problems with the seams, using Solartex.
11-17-2009, 06:45 AM
#15
RE: sealing seams with koverall
ORIGINAL: stevenmax50
Hey Carl, nice info in your posting. I used koverall and Sig Stix-it on my last model and i want to go fabric again. I much prefer the look to monokote. Could you enlighten me on a couple of things on your technique?
BTW, I will spray the koverall with hair spray before cutting to make a clean cut to keep the fuzzies way down.
Question 1. When do you start the shrink process? And how much at a time do you shrink?
I stuck the coverall at the seams everywhere and then sharnk the coverall down to taught. I then brushed on Minwax Polycrylic. 3 coats, not thinned. After that I would sand after each coat of Poly. I then primed with an auto rattle can primer. I had the local auto parts store mix me some paint and it went on well with my Lowes compressor/sprayer. I thinned the paint by about 25%.
Question 2. Will you switch to a fabric covering with the adhesive already applied? If so, which one? I think I would like to try that next time myself. But to be honest, I do not think the seams are very hard when you use Polycrylic as the sand smooth easily. The thing I found most difficult was pulling out and shrinking out the wrinkles in the curved areas. That might not be any less difficult with a pre-adhesive applied fabric.
BTW I will be starting a build thread for my new Tiger 60 when I get it. My B-day is in 2 weeks and I have let it be know I can get the engine/radio for Xmas. Just get me the plane now so I can start building. Looking forward to any advice from anyone and everyone.
Hey Carl..... Roll Tide Roll
Hey Carl, nice info in your posting. I used koverall and Sig Stix-it on my last model and i want to go fabric again. I much prefer the look to monokote. Could you enlighten me on a couple of things on your technique?
BTW, I will spray the koverall with hair spray before cutting to make a clean cut to keep the fuzzies way down.
Question 1. When do you start the shrink process? And how much at a time do you shrink?
I stuck the coverall at the seams everywhere and then sharnk the coverall down to taught. I then brushed on Minwax Polycrylic. 3 coats, not thinned. After that I would sand after each coat of Poly. I then primed with an auto rattle can primer. I had the local auto parts store mix me some paint and it went on well with my Lowes compressor/sprayer. I thinned the paint by about 25%.
Question 2. Will you switch to a fabric covering with the adhesive already applied? If so, which one? I think I would like to try that next time myself. But to be honest, I do not think the seams are very hard when you use Polycrylic as the sand smooth easily. The thing I found most difficult was pulling out and shrinking out the wrinkles in the curved areas. That might not be any less difficult with a pre-adhesive applied fabric.
BTW I will be starting a build thread for my new Tiger 60 when I get it. My B-day is in 2 weeks and I have let it be know I can get the engine/radio for Xmas. Just get me the plane now so I can start building. Looking forward to any advice from anyone and everyone.
Hey Carl..... Roll Tide Roll
2. I will shrink an entire wing at once. You have to be careful. Fabric is strong as heck and I have had smaller wings warp because of it.
3. I don't use fabric coverings with the adhesive already applied. I prefer to use plain fabric. It's cheaper.
Fabric is easier to get to mold around corners,edges, etc. than monokote ever hoped to be. It's one of the reasons I use it. However; sometimes it can be just a little tricky. Practice and patience will get it done.
I've read finishing techniques similar to yours before. I do it differently because I'm a little more traditional. I use Nitrate dope: 1. as a glue to stick down the fabric, and 2. to fill the weave like a primer. I will then top coat with either butryate dope or paint. I don't use a "paint" primer. I'm afraid that it will crack over open wing areas. It is a simple system that has given me good results.
By the way, at my house it's "Big Orange" country.
11-17-2009, 06:51 AM
#16
RE: sealing seams with koverall
WacoNut,
Your planes are quite impressive, to say the least. I'm close to being ready to start covering my giant scale astro hog and am waffling over a full blown butyrate dope finish or top coating the nitrate with exterior latex house paint.
In years past I usually top coated with Hobbypoxy but they are gone now. I tried Nelson's linear water based polyurethane but I didn't care for it. Not to say that it isn't a great paint but it wasn't for me. Butyrate dope is easy but I would really like to try latex house paint.
Your planes are quite impressive, to say the least. I'm close to being ready to start covering my giant scale astro hog and am waffling over a full blown butyrate dope finish or top coating the nitrate with exterior latex house paint.
In years past I usually top coated with Hobbypoxy but they are gone now. I tried Nelson's linear water based polyurethane but I didn't care for it. Not to say that it isn't a great paint but it wasn't for me. Butyrate dope is easy but I would really like to try latex house paint.
11-17-2009, 06:37 PM
#17
RE: sealing seams with koverall
ORIGINAL: chuck l
Beautiful Waco, WacoNut. Whose kit or plans was it? I built a 1/4 Peter Barth Waco a few years ago and sold it. I'm giving serious thought to doing it again, except keeping it much longer.
Chuck
ORIGINAL: WacoNut
I prefer to stick the Koverall down with dope,
I have used PolyC for filling the weave and hiding the seams and it works very well also. The PolyC has to dry good before it will sand without balling up. If the finish is done properly all the seams will all but dissapear. I have used Latex paint as well as Krylon spray cans with good results over the Koverall. My 1st plane covered with Koverall was my 1/4 Cub and it is 5 years old and still looks new. No more plastic film being used on my planes. Here are a few of my planes covered with Koverall.
Later!!
Anthony
I prefer to stick the Koverall down with dope,
I have used PolyC for filling the weave and hiding the seams and it works very well also. The PolyC has to dry good before it will sand without balling up. If the finish is done properly all the seams will all but dissapear. I have used Latex paint as well as Krylon spray cans with good results over the Koverall. My 1st plane covered with Koverall was my 1/4 Cub and it is 5 years old and still looks new. No more plastic film being used on my planes. Here are a few of my planes covered with Koverall.
Later!!
Anthony
Chuck
Thanks for the comments, the Waco is built from Pepino Plans. I am very proud of the Waco but I wouldn't build that thing again for love or money. The plans were full of errors and I spent numerous hours correcting issues with the plans before cutting the 1st piece of wood. I am currently building a AMR 33% Waco and it is a nice build. You can see my thread in the scale forum. I believe AMR has reduced the price of their kits due to the poor economy so if you are looking for a good Waco kit now is a good time to buy.
Carl,
I used Latex on the Cub and the Ercoupe and it worked out very good, I applied the latex with an HVLP gun with the paint thinned approx 40% with windshield washer fluid. 4 light coats of paint cover very nicely.
Later!!
Anthony
11-17-2009, 08:17 PM
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RE: sealing seams with koverall
13 more days until my Tiger 60 gets here (birthday). I cant wait to get to building again. I wish I had the skill to build a bipe like Waconuts from the plans only. What with the way kits are becoming extinct I dont know if I will ever be able to by a bipe kit of that quality. I have no desire to buy an ARF. If all goes well with the Tiger my next kit after that may be a bipe. Covering a Stearman absolutly requires using fabric.
I will probably stick with the Koverall for my Tiger as I still have alot left over from my last build.
Hey Carl, where do you fly? I have a mother and brother living in Decatur and make it over that way at least once a month. I've never been to the field in the Decatur area and would like to check it out sometime.
I will probably stick with the Koverall for my Tiger as I still have alot left over from my last build.
Hey Carl, where do you fly? I have a mother and brother living in Decatur and make it over that way at least once a month. I've never been to the field in the Decatur area and would like to check it out sometime.
11-18-2009, 01:19 PM
#19
RE: sealing seams with koverall
I fly with the Decatur Model Airplane Club. We have two fields. Send me an email to [email protected] the next time you want to fly in Decatur and we will go flying.
Don't fret about the loss of kits in the industry. There are plenty available at swap meets. Once you have built a few kits (including maybe an old Sig kit), you will have enough experience to start scratch building. It is much more rewarding and you can tailor the plane to your own personal preferences. It is also not really much more difficult than kit building. Cutting out parts isn't difficult, just a little more time consuming. There are TONS of fantastic plans out there that you can be sure no one is going to show up at the field with.
Don't fret about the loss of kits in the industry. There are plenty available at swap meets. Once you have built a few kits (including maybe an old Sig kit), you will have enough experience to start scratch building. It is much more rewarding and you can tailor the plane to your own personal preferences. It is also not really much more difficult than kit building. Cutting out parts isn't difficult, just a little more time consuming. There are TONS of fantastic plans out there that you can be sure no one is going to show up at the field with.
