I am applying Super Coverite fabric with Balsarite brushed on the structure. I have some Nitrate dope that I was thinking of using to seal the fabric and then paint with spray enamel. Do I need to use the Nitrate dope? What benefit will I get from using it?

I have also thought of using latex paint with water based polyurethane clear coat. Would the Nitrate dope offer any benefit under the latex?

The plane has a gas engine so glow fuel resistance is not an issue.

I use nitrate dope over the polyester fabrics and usually use epoxies or Rustoleum for the color coats. Paint adhesion to the polyester fabrics has traditionally been a problem. Note that the Stits system has a "primer" that looks like very viscous nitrate dope. I don't have much experience with latex. The only risk of using the nitrate is the small amount of weight gain.
Chuck

I read in a British mag several years ago that Nitrate dope "stabilizes" the poyester fabrics. I assume that means helps keep it tight.

Paul

Several years ago I was involved in recovering of a 1:1 Taylorcraft BC-12D. I did a lot of research on the stits system. The one constant through all of his videos and paperwork was that YOU DO NOT USE DOPE on stits type fabrics. Traditional coverings soak up and bond with the dope and cause shrinkage. The polyester based fabrics are shrunk with heat, and the plastic nature of the threads does not allow the dope to stick. It may fill the weave for a while while it's wet but when it finally cures out, it flakes off.

Have a look

http://www.polyfiber.com/stits/

http://www.stits.com/

HTH

Tom

Tom, the stits system uses the Poly-Brush as the first coat to fill the weave. Is the Poly-Brush not Nitrate dope already thinned and ready to spray?

There seems to be a split on what to do, which is why I posted the question. I have been told to use the Nitrate dope to fill the weave and it will also have shrinking properties added. The Super Coverite already shrinks good and is much easier to work with than the films so I am not sure the shrinking properties of the dope is needed.

Chuck, if the dope helps paint adhesion it will be worth the weight penalty. However, Tom posts that the dope will not stick and will flake off too.

Maybe I need to get more info on latex...

The instructions with the 21st Century Fabric call out for the use of Nitrate Dope when using mutiple color schemes. This is to increase the bond of the first paint color so the masking tape will not pull it off when finished with the second. I have some ordered now for my Adrian Page Gee Bee R2 and plan to use if where the red goes and, I need to blend the fabric look into the uncovered fairings so the nitrate dope will act as a primer to help eliminate the transition priop to painting the final color coats.

Regards,
Randy

I have covered 2 models with Sig Koverall fabric using nitrate dope to adhere to the wood and as a sealer. I have used latex paint over the nitrate dope. The paint adheres to the dope very well. One of my planes is in its 5th season, the other has been flying since March this year, the finish holds up perfectly. I run gas engines in mine, as well.

Good luck with your project.

Jim, did you use any clearcoat over the latex? Or does the latex hold up to the gas without a top coat.

The latex holds up to gas very well. I did top coat with water based polyurethane to seal some non latex trim and vinyl graphics and just to give it all a satin finish. Otherwise, the latex doesn't need it.

You might want to read this: http://www.nelsonhobby.com/paint.html

Haven't tried it yet myself, but it's interesting where it says "CLEAR DOPE NOT NEEDED ON FABRIC.....Clear doping of polyester fabrics commonly used on larger model aircraft need not be filled or primed with clear dope. The paint is applied directly onto the raw fabric. A lighter weight finish is the result of using this paint. Crosslinker required on open fabric surfaces." I am thinking of trying this on my current project, a Sig Liberty Sport.

EDIT: Of course, they are referring to their paint product only, not others.

Thanks for the info Jim and others. Jim, did you use Nitrate dope on the fabric before painting? It looks like the Nelson product is painted right onto the fabric without any dope or primer.(I know Nelson is not latex) Is primer not needed for latex?

I guess you can see that I am leaning toward the latex as my paint choice. Any info on using latex on Super Coverite is appreciated.

I'm pretty sure that Roy Vaillancourt at [link=http://www.vaillyaviation.com/]Vailly Aviation[/link] has experience with latex paint over fabric. Probably worth shooting him an email.

Yes, I used nitrate dope on the fabric to seal it and to adhere the fabric to the structure underneath. I used 50/50 thinned dope, 2 or 3 coats