H5487

I know that when covering an airplane with silk, the first coat of dope is supposed to be nitrate and the follow-on coats are to be butyrate. However, when I looked through the Aircraft Spruce and Specialty catalog for nitrate dope, Randolph makes both 'tautening' and 'non-tautening' formulas. I know the difference between the types but I don't know which is appropriate for R/C. Will the 'non-tautening' nitrate dope shrink enough? Will the 'tautening' dope shrink too much and crush a balsa structure?

I'll be using it primarily on Thai silk.

Thanks,

Harvey

maukaonyx

I used to build free flight rubber and gas planes, and covered them with Esaki Japanese silk. Once the silk was on the plane as snug as I could get it, I used a spray bottle to mist the silk and shrink it. I then used Nitrate dope for rubber planes and butyrate Aerogloss for glow planes. Never did use nitrate first, then butyrate, and my methods worked fine. I have never heard of using nitrate first then butyrate for addtional coats till you mentioned it. ALso, I have never heard of a non-shrink vs a shrinking nitrate formula. Maybe I am too old. Both the nitrate applications and butyrate applications for rubber and glow respectively simply maintained whatever tautness I had managed to obtain when I fastened them down to the balsa frames. And neither the water spray nor the dope apps ever crushed the balsa structures. Jon

LesUyeda

Here's the deal. Nitrate sticks to about everything, and you can put almost anything over it. Butyrate is selective about what it will adhere to properly, and the only thing you can put over butyrate, reliably, is butyrate.

Les

Rodney

Yes, it is recommended to use nitrate dope for the first few coats, as many as it take to fill the weave. For a fuel proof finish, the last coat or two needs to be butyrate. As mentioned above, you can not reliably put anything over butyrate other than more butyrate. There are additives you can put into the nitrate dope to minimize how much it will shrink and to prevent blushing if you are in a high humidity atmosphere.

muzzlemaggot

My Feedback: (7)

Oh, how I miss the smell of dope!

H5487

Be careful on how loud you say that!


Hey, thanks to all of you who have responded. Using nitrate for the first coat or two due to its stickability and then butyrate for its fuelproofing characteristics is pretty much what I remember. However, I'm still not sure whether to use 'tautening' or 'non-tautening' nitrate.

Remember our military today, as well as every day!

Harvey

JohnBuckner

My Feedback: (1)

And the smell of the Banana Oil sold from the back of the hobby shop in your own container for the plastiziser.[8D]

LesUyeda

taughtening

Les

H5487

Thanks Les!