Mixing different brands of dope

What I'll do is try it on some test wood. I don't know why I didn't think of this before posting.

I paint outside to avoid the worst of the fumes. Thanks!

nitroairplane wrote:To me butyrate is butyrate and I mix an match when need be.
Try a small quantity and see,
Remember well ventilated area.

BBreyer wrote:

What I'll do is try it on some test wood. I don't know why I didn't think of this before posting.

I paint outside to avoid the worst of the fumes. Thanks!

nitroairplane wrote:To me butyrate is butyrate and I mix an match when need be.
Try a small quantity and see,
Remember well ventilated area.

Ah, I love the smell of cellulose in the morning!!

You can keep your modern variations, to me dope has to be cellulose, or it aint dope!

If you do get the Brodak colored butrate,,also pick up the reducer and thinner. There colored butrate goes on very thick and drys extra fast unless it is thinned and reduced. I ended up purchasing a quart of each, after both small cans I intially purchased ran out fast,,

Brodak highly reccomends not to mix with other brands. I have applied the Sig clear butrate underneath the colored (thinned reduced) Brodak and didnt see a crazy reaction. I tested on scrap before commiting to a finished model.

Good luck Ben

BRODAK dope is a Randolph formulation, but I've heard that it has more solids added to improve filling and covering. I believe that SIG is also a Randolph based dope. The only incompatibility I've read about is Brodak or SIG over Aero Gloss. To ensure no problems, you may want to allow the sanding sealer to gas off for a few days in a warm area. Brodak is rumored to "dry" more quickly than SIG, so if it sets up before the underlying coat cures, you can get bubbles. Either butyrate thinner should work fine. I've used lacquer thinner from Lowe's to thin colored dope, but some clumped up, consequently, I just use it for cleanup.

You can get Randolph thinner plus clear and colored dope from Aircraft Spruce and from Airsuppliers.com for significantly less than model suppliers, but the minimum size is a quart. You can buy quarts without a hazmat fee.

I buy clear and thinner from them, but usually buy colored dope in smaller amounts. You must be careful when buying butyrate and nitrate to get the non-tautening formulation when painting over solid surfaces. The tautening formulation is used only over open areas.

Lots of great advice. For the color coats, how much reducer should I add when airbrushing? I usually go 50/50 on dope & thinner if I'm spraying.

BBreyer wrote:Lots of great advice. For the color coats, how much reducer should I add when airbrushing? I usually go 50/50 on dope & thinner if I'm spraying.

Yeah I do it depending on how much nitro I will be running through the engine or if diesel I put more on.
But yeah what you are doing sounds about right.

Having a had a recent Brodak butyrate "experience" I can tell you not to go light on ordering retarder, reducer OR thinner. I'd order AT LEAST 2X the volume of butyrate dope that you intend to apply.

No I do not recommend mixing different brands of butyrate otherwise be ready to experience "unintended consequences".

The air temperature for air brush application should be about 70-72 degrees.

A really good page I went back to several times as I was using the Brodak stuff. Good tips and advice that were on the money. Save it to favorites everyone!

http://www.agroponic.com/brodak/brodak_tips.htm