Hello; I am trying Sig Koverall for the first time on my "Flybaby" and I am using Stix-it to put it on. I read here where one person thinned the Stix-it with nitrate thinner and put on two coats before putting on the Koverall, can anyone tell me how much to thin the Stix-it. After I put the Koverall on I am supposed to fill the weave with nitrate dope. Do I put the nitrate dope on full strength or do I thin this too? Can I use a foam brush or will the dope eat the foam? I would appreciate any information I can get on using the Koverall and the Stix-it. Thanks Cal.

I have never used the sticks it process but I believe the fill the weave is the same. First you need to get some plasticizer sold by Dave Brown, its actually castor. It stops the dope from getting brittle with age. I then coat the frame with 75% thinner solution, sanding between each coat to nock down the high spots. After three coats of this the Koverall can be ironed on (just like Monokote), in those areas where the curve is to tight ad some of the dope and Iron while wet and it will stick. Put a total of three coats of the 75% thinned on the fabric to glue it right down, again sanding after each coat only to knock down the high spots.

Now the plane is covered thin the dope 50% add just enough to cover the bottom of a 1 quart can to about ½ an inch. Then add 2oz talc and ½ oz ground aluminum (I’m just guessing here I do it until it looks right). With a good brush (one that will apply the mixture evenly) brush on the mixture we just made. Remember to never brush in the same direction from coat to coat and sand lightly between each coat. After three coats most of the weave should be filled but there will be trouble spots, usually over sheeting. The silver should make finding them easier, I will start looking for those spots after coat two and rub the mixture into those areas with my finger then comeback and go over it with the brush just before putting that peace down. Usually it takes three coats for me to fill the weave but I would not think twice of going to five coats if I needed it.

I hope this helps

Joe Felice

Re the Sig coverall . best thing I've found to stick the coverall on with is waterbase contact cement , I use Lepages , can get it in Canada . put a coat on all around airframe edges , let dry , sometimes i put another coat , although not always neccessary . Now depends what finish one wants , I used to always mix 50- 50 nitrate dope & thinners , can use laquer thinners as thinner is cheaper . Sorry to back up , iron on the cloth around the frame to contact cement then shrink it on . then onto the 2 coats of dope . HOWEVER- On my big birds I went to Home depot & bought some Behr latex paint , never used any dope & brushed that paint straight on coverall . works good

Well, here we go. Seems like we've had this same discussion countless times here on RCU. But it is one we never seem to get tired of. Especially when it brings builders who use the plastic film coverings into something "better".
Ok, so here goes...

My personal favorite, Koverall. Sig has been making this stuff for... well, forever. And it is a polyester fabric that is very light weight. About 1.25oz/yd. It is sort of a compromise to silk. It is synthetic, so it is much less expensive than silk. Actually it is one of the most affordable out there. I really like Koverall because it is applied just like silk. Here is a basic application process so you can get an idea of how it is used and turns out.
a. First you apply two coats of Nitrate dope to your balsa model framework all over where the koverall will be in contact with the wood, sanding lightly between each coat. (thin it anywhere from 2:1 to 1:1 ratio of thinner)
b. Once doped with nitrate, then cut out the fabric to cover the entire area with about an inch of overlap for good measure. Then place the Koverall over the wood and paint a thin line of Nitrate around the edges so it soaks through and softens the nitrate underneath so it will tack the cloth down to the surface around the edges. Pull it gently smooth so you have no wrinkles. You can even use some small pins around the overlapped edges to hold it in place until dry. Wait until completely dry.
c. This is the nice step. Unlike silk, which requires Butyrate dope to shrink, Koverall does not. Shrink the Koverall over the undoped areas with an iron. Shrink it only as needed, as not to shrink too much to warp the structure, or not enough, thus leaving sags in the open bays.
d. Then you can use the Nitrate dope again to begin applying the sealing coats. Generally two good coats of Nitrate will seal the fabric, but three may be needed, sanding lightly between each coat. When dry, trim off the excess around the edges just like you used to do with monokote, then sand edges smooth.
c. Now you are ready to apply your finish.
1.If you want a fabric textured finish, then you can use colored dope to paint on your design, or you can spray it if desired. If you choose enamel finish like rustoleum, which I use quite a bit because of all the colors it comes in, then lightly prime and paint as you see fit. Butyrate is fuel proof, and is nice in the fact that it is glossy and usually does not require a clear coat finish.
2. If you want a glass-like finish with no fabric texture, then add another one or two coats of Nitrate dope mixed with some talcum powder to fill in the texture. Also what is very cheap to use is primer filler in spray cans. It fills the weave completely, and when sanded gives a perfectly smooth surface. Then you can apply your enamel finish over it.
3.To finish it off, you can apply a coat or two of two-part automotive clear coat with a flex additive to seal the entire plane. This is really a good idea if using rustoleum, which is pretty fuel proof but not infallible. If you used some other kind of finish like latex paints for a camo finish etc, then a clear coat enamel is necessary to prevent from turning your nice paint job into a gooey mess. Clear coats can be gotten in satin or flat for camo finishes.

I have to say, of the several coverings I have used, thus far I prefer Koverall the most. Mainly because it gives such a nice finish when done right, and it is so versatile in the type of finish you want to apply.
Also, unlike every other iron on covering on the market, Koverall can be doped around the edges to the point where you can gently sand and completely cover all of your seams. It is so neat to see an entire plane covered with a shiny finish and absolutely no visible seams anywhere on the plane. It looks very professional, and has all the guys who have never used it, wondering how you got all that monokote on without any seams. Although a good fabric finish can never be confused with monokote.

Oh, one last thing about Koverall compared to monokote. If you puncture monokote it will tear very easily, like a plastic candy wrapper right? Not Koverall. Koverall is a fabric weave, and it is extremely tough. Way stronger than monokote. Don't believe me? If you get the chance, get ahold of a piece of plain unfinished Koverall, and try to tear it.

I hope all this helps, my fingers are getting tired of typing.


Patriot

P.S. Here is a pic of the finished wing for my Citabria Pro.

_____________________________

A man who learns from his own mistakes is very smart, but a man who learns from the mistakes of others, is truly wise. Adm. H. Rickover.

Thanks guys!!!!! I appreciate all your info. The only other question I have is about the foam brushes. Can I use a foam brush to brush on the nitrate dope? I just thought it would leave a nicer finish without any brush strokes and they are cheap. you can buy them by the bag so you can just use them and then throw them away. Thanks again for all the info. Cal.

To Calmo2:

For 25 years now I have used nothing but Ceconite to cover my planes - all 1/3 scale or larger. Ceconite is like Koverall - same generation of fabrics - but is certified for full scale useage. I apply using Ceconite "super seam glue", that is thinned 50/50 with laquer thinner. I brush one coat onto the wood - then brush through the fabric while covering. For a wing - I wrap the fabric around the leading edge - only gluing at the trailing edge and ends. This gives a "no seam" leading edge.

After the glue has dried overnight, I shrink using a heat gun - but be careful here - keep the gun moving. A safer way is to shrink with an iron, but when you have covered as many planes as I have, the gun is a whole lot faster. I then apply three coats of nitrate dope, thinned 50/50 with laquer thinner, using a bristle brush (the cheap ones). Then I paint the fabric using latex high gloss exterior paint. I like Behr from Home Depot, and Sherwin - Williams paints best. This is applied with foam brushes - (the good ones with the round handles). Five coats - thinned to cream consistency- brushing each coat in a different direction. When finished - no brush marks are visible.

IMPORTANT: I only fly gasoliine engines - so the paint never gets messed up. Don't know anything about using glo with this type finish.

After the airplane is fully completed, and all decals applied, I spray it with Bissell Furniture polish wax, and rub dry. This gives it a nice gloss. I hate plastic finishes.

Thanks Jim; I have already bought the Koverall and stix-it and tried a practice piece and it seemed to turn out alright, but I have not filled the weave with dope yet. I have heard about people using latex house paint and then fuel proofing it for glow fuel. My friend here has used "Tremclad" spray paint on a couple of his planes and it seems to be fuel proof. I am planning on painting my Flybaby orange and white with the Tremclad and then fuel proofing it with Coverite clear. But I plan on trying it on my practice piece first to make sure the paint, the dope and the clear coat is compatible. Thanks again for the reply! Cal.

I personally would not use foam brushes, because the amount they apply is not as uniform as a good brush. I had a problem with brush strokes, so I went out and bought a very high quality soft and fine synthetic bristled brush. They are only about $5, and clean up easily with lacquer thinner. I also thin my nitrate dope at least 1:1 with lacquer thinner. If done carfeully, you will have very little brush strokes if any. nothing a good fine steel wool can't remove.

Patriot

Thanks Patriot; I think I will go with a brush then. You thinned your 1:1 with lacquer thinner, all I have is nitrate dope thinner, can I use that in a 1:1 mix to thin down my dope.
Cal.

Actually, that is preferred. Nitrate dope thinner is made for nitrate dope, so it should be perfect. I just use lacquer thinner as a cheaper alternative.

Patriot

I thinned the Nitrate 50/50 and just finished applying the 2nd coat, it is official my wife has finally lost her sense of humor about my plane The fumes from the dope finally made it up from the basement.
Later!!
Anthony

hello...i have had great results using water based polyurathane...10 bucks a quart at wally world...no fumes to worry about....two coats of polyurathane...let dry....then cover with koverall....then two coats polyurathane....paint with rustoleum.....no need to clear coat rustoleum...its nitro proof......pault

Well here is the Stab for my 1/4 Scale Cub, it turned out real nice. I still need to put a couple of coats of Dope on to seal the farbric.
Anthony

I too like Koverall a lot; once you get the techniques down, it's so easy to do some great covering work. I just use 50/50 nitrate to stick it down too.

Nice work Gents! Through the winter now, I have sort of lost my interest in planes, and took up bicycling to get back into shape. Now that summer is coming, I think it's time to start pulling out the planes and tuning them up.

Calmo, It's been a while since the main discussion on this thread but did you try the Tremclad on your Koverall?? How did it work out?