Which better or preferred way to put on ployspan. nitrate or butyrate dope. I also have some SIG stix-it to. The wing to be covered is a Stiletto 660

HI Alan. I use both. It's and either or situation. I like Nitrate as it appears to fill the wood quicker and is generally thicker.  I apply 4 or 5 sanded coats to the wood, until it is sort of shiny, then use thinner to dissolve the dope through the covering.  I rub it in with my finger tips. Then once it, the dope is dry, I use the heat gun. Very carefully. My first time I melted runs in one wing.  Keep the shiny side of the polyspan up. But then you knew that.   

Ty,
Have you used it on a "Polywog" type airfoil and if so, did it hold?
Roger V.

If you have a really serious problem with polywog or undercambered airfoils, you might take a look at "Fabric Cement" at your light plane supply store of choice. As I understand it, it's used for the pinked tape over the ribs and such on fabric covered planes. It can be used much as Duco or Ambroid, and I suspect it's very close to Duco (or "Tarzan's Grip") household glue.  Steve

Hi Alan,

I really like NITRATE for my substrates and to attach covering.  Bob Hunt turned me on to it many years ago.  I usually use Sig, since I can get it when I do make it to the Hobby shop.  But I prefer to use Randolph's Non-Tautening Tinted Nitrate.  It is my favorite.

Big Bear