Butyrate Dope
 

Anybody out there still using butyrate dope to finish their rockets? I am in the process of painting an Astrobee 1500 (Peter Alway kit) and I am amazed at the results! I may just never use regular paint (acrylics, water-based, etc.) again! I am spraying it with an airbrush and it has a couple of HUGE advantages over the traditional paints I have always used, so I thought I would try to start up a discussion thread here to see what you guys are doing to finish your models. One disadvantage of dope..............it can be kinda hard to find.

Joe

I use it to fuelproof balsa on R/C planes, but I haven't airbrushed it on anything. Mmmm butyrate dope....I love that smell. :D

I use original Pactra Aero Gloss Butyrate out of an airbrush to finish rockets all the time.
I find it to be vastly superior in the finished results versus paint cans, provided one takes their time and uses lots of coats.
It helps that I have several cases of pint and quart cans of most original colors (EVEN Royal Purple, which has been discontinued for at least 20 yrs.) :D
I ALWAYS use good-old-loaded-with-flammable-organic-solvents Aero Gloss Balsa Fillercoat and Sanding Sealer to finish balsa parts....none of that mamby-pamby water based Elmer's Fill n' Finish for me !

Although Aero Gloss new old stock can still be found sometimes on ebay, otherwise it is VERY hard to find.
Sig Butyrate used to be easy to find, but is not anymore.
The ONLY source of a good assortment of Butyrate colors is now Brodak, unless you want to buy in full-scale aircraft finishing quantities.

Part of the fun of being a BAR is using the nostalgic finishing techniques that make the environmentalists cringe ! :D :p :D

Should be easy enough to find at Sig. www.sigmfg.com.
I see the sanding sealer and thinner all the time at Hobby Lobby.

Aero Gloss is still in lots of hobby stores, but you won't find a full selection. Did Midwest just stop all production or did they sell it to someone else?

This is weird! I was at the local hobby shop yesterday, looking for sanding sealer. I wanted the good-'ol solvent based stinky stuff to finish the lumber in my Interceptor. I wanted to break from using fill 'n' finish and try that. They did not have any solvent-base stuff, but they did have some water-base stuff for pinewood derby cars.

I decided to try it, but I'm not sure how good it will work. I think it will work OK, it will just need lots of coats.

Anyhow, this hobby shop did have a good selection of Sig Butyrate dopes. I looked that those pretty hard, but didn't have a clue how to use them. Can dopes be applied with a brush? Do you sand between coats?

Can someone detail a procedure for finishing balsa with dope? Can a guy use it on the whole rocket, or just the wood? What kind of finish quality can you get using it?

I'm just curious about alternative finishing techniques....

Hi Joe;

I use dope and tissue to fill my fins before I prime. The past few years, I've moved away from Butyrate dope to Nitrate, mainly because there is less shrinkage with Nitrate (and hence less warpage), especially important on thin fins.

I like this method a lot; it's very clean, with little to no dust when sanding. Three coats of dope (sanding in between) and I'm ready for Primer.

I've sprayed color dopes a number of times, but I still prefer enamels or lacquers mainly because of the local availability of a broader range of color choices. But that doesn't mean that color dope can't deliver a top quality result, and I've seen many examples where this is the case.

I've been using my finishing system for years, and since it works for me, it has become such a comfortable rut that I doubt that I'll ever move out of it until forced to. Fill n' Finish is a wonderful product, and there are many, many examples of catalog-quality finishes based on this product, but I've never been able to rationalize in my head the use of a water-based product on wood and paper - nothing scientific, just a personal preference thing. All finishing systems eventually become a personal thing; once one finds a system that delivers the expected satisfactory results, one tends not to deviate (why mess with success?). So while I have my preferred system, I nevertheless am always interested in learning about new or different systems, what combinations work and what doesn't, and what new products are coming onto the market that might remove a few steps from the finishing process (a zero-sanding scheme would be nice...).

I for one will be very interested in following your experience with color dopes, and hope that you'll have the opportunity to share a few photos of your experience as you move along.

Fascinating to hear about the interest in dope finishes. I started ordering Estes stuff in the 60s (yep, nothing in the stores back then!). Estes sold small bottles for 25 cents, as I recall. I thought the finish was pretty decent, and we are talking brushed. Then again, it may be the time lag, and the fact that I THINK they looked good. :)

However, I am intrigued about airbrushing with dope -- since I have a couple airbrushes, and I've been wanting to start painting with them again.

Yep, my Deluxe Alpha Starter kit came with red and white Testors dope, a bottle of thinner and a bottle of sealer. I followed the Estes instructions, and I got a hard, shiny finish but the balsa still showed plenty of pores (I guess I didn't sand enough off between coats). And dope had two big problems. 1. It didn't stick well to glassine. It was ok if you didn't get any scratches, but once scratched, it would be easy to peel or scrape off. 2. It continued to shrink on the outside for weeks, meaning that you'd get these bubbles webbing across fillets, which would eventually crack and cause unsightly gaps around the fillets.
The airplane guys said, add some castor oil to the dope and it would stop that, but I never tried it.

The factory that produced Aerogloss dope for Pactra/Midwest and color dope for Sig burned down a few years ago and is not being rebuilt; any of these brands on shelves is new-old-stock and not new production unless clear, Sanding Sealer, Fillercoat, or Nitrate.

The only company selling new stock color butyrate dope (outside full-scale aircraft industry dope such as S****) is Brodak....don't know who produces it for them, but I suspect it may be S****.

One must be very patient in applying dope over several thin coats....if you shoot it thick it will bubble and shrink for months.

Hmm. so the fact that any of the colors are still on the shelves means there's not much demand anyway. The Monokotes and Ultrakotes introduced 40+ years ago have apparently taken the market.