Sig nitrate dope?

Anyone know if Sig nitrate dope is the non-tautening varity? This is my first attempt at using nitrate dope for putting silkspan on. In the ancient past I'd always used butyrate dope from the LHS. The nitrate dope doesn't seem to shrink the silkspan as much as I remember. Bad memory? or less shrinkage? or maybe differences in the silkspan?

Sig nitrate is a no shrink or very low shrink dope.

Brodak nitrate seems to be a shrinking nitrate.

>Sig nitrate is a no shrink or very low shrink dope.
>
>Brodak nitrate seems to be a shrinking nitrate.

ahhh ha! good info for future reference. I'll try Brodak dope next time. Would putting a coat of Brodak dope over the Sig dope shrink the silkspan at all?

Putting Brodak over any form of Sig is most probably a major no-no.

If you need shrinkage, try putting on a coat of Sig Supercoat butryate clear over the nitrate

I agree with Steve. What ever you do DO NOT put Brodak dope over Sig dope. You will be sorry and never forget the experience. The real challenge for many of us finding a quick and safe system to paint our planes. After studying and trying a few methods, all Sig products with Dupont 3806 thinner has been good. Brodak products for a base coat and Sig Colors for trim with Brodak Clear have worked. I have had better luck with Sig litecote than with supercote dope, it can warp a wing if you are not careful. I am personally staying away from the auto paint finishes as I have no experience with them and they are costly. I did "inherit" some Omni clear and may try experiments with that. All have had a bit of retarder added. I also spray during the warmest part of the day 10 AM to about 6 PM depending on the weather. Painting indoors is prefered but not possible in my house. Brushing dope is harder to control as the same amount seems to go on with a one inch brush, I stay with the same products when brushing. Also Ultracote has worked well but if you just use the clear over dope it starts to peel off after a season of flying. May try the Pacer epoxy wipe down method and Ultracote next on the body only. Seems this subject has many opinions on how to get things done. The Brodak products are fantastic, though I think the thinner and clear dope is over priced. $40 a gallon for thinner is a bit much for me and I know someone that is using the cheap thinner and Rustoleum from Home Depot. My big lesson came when I put Brodak primer over Sig Supercote clear and the whole thing crackeled....plane is still not done. Seems some of this stuff doesn't "gas off" at the same rates. I would bet if you waited a month between coats of paint you could pull it off. Jim J.

Ron,
If you look at the Sig Nitrate label, it mentions NOT to use with silk (over open bays) but to use the clear SuperCoat butyrate instead. I read that after using it to fill my silked wing (isn't that always the case!). I am not sure about silkspan, I would have thought it would have shrunk a lot just from the initial wet application.