driverm391

I noticed that to dope that you buy in the stores ( if you can find it) is pretty expensive. My dad is an AP mechanic that used to do fabric aircraft coverings (full size aircraft). He picked up a gal. of thinner and a gal of dope. As it was a gift, I am not sure hjow much$$, but he said it was cheaper.
The company name it came from is
AIRCRAFT SPRUCE & SPECIALTY
GRIFFIN, GA
I don't know if there is a website but it is worth checking out

LesUyeda

Try this:

http://www.aircraft-spruce.com/

But watch out for the Hazardous Materials shipping charge. It is cheaper to buy 4 quarts, that 1 gallon.

Les

kdheath

It's likely to have been made by Randolph. They are the major maker of nitrate and butyrate dope products. They make the dope that Brodak Mfg sells for modeling. Great material!

http://www.randolphproducts.com/index.htm

http://www.brodak.com

driverm391

I didn't know the site, thanks.
The is a Haz-Mat BOL on it the brand name is Certified Coatings.
The price that they charge for SIG dope $7.99/pint is kind of steep these cans are $19/gal for the dope and $13/gal for the thinners

kdheath

Yep, that's why the airport stuff is a good deal. I didn't know CC made dope, too. It's shown on the Spruce and Speciality site with equivilent Randolph color numbers. Price $33 to $56 per gallon.

driverm391

Yeah, my dad said when there was more fabric covered aircraft, he went through it like water.
Nowadays, not aot of people know how to do it, its like a lost art.

JWN

My Feedback: (42)

Can anyone verify that dope thinner is nothing more than denatured alcohol? Possibly a higher grade than you can get at the hardware store. They both smell the same and I've used the D.A. to clean my brushes. I'm just not sure I'm ready to try spraying a finish with it.

Thanks,
John

LesUyeda

Definitely NOT alcohol. A good quality automotive laquer thinner will work.

Les

Gollywock

Not to be confused with cheaper hardware store thinner which evaporates too fast, but good for clean up- Jim

JWN

My Feedback: (42)

Lacquer thinner? Hmm, it and Sig dope thinner do not smell anything alike. But, that doesn't mean it won't do a great job. Especially when you consider how a high quality lacquer thinner leaves nothing behind to mess with the paint. I generally use Dupont's thinner for painting. Of course, that was back when I had access to a compressor and spray gun :-(

John

Strat2003

My Feedback: (1)

It's my understanding that lacquer thinner is the proper thinner for nitrate dope. (It's my understanding because that's what I use and it works, lol) The thinner for butyrate smells different and I don't believe lacquer thinner will work.
By the way, I buy my nitrate dope from Aircraft Spruce, too, and it's also made by Certified Coatings.

GSNut

My Feedback: (8)

[&:]

Spose I'd be giving away my age...but then why not...going on 68..so there...heheh...

We used to make our own.. n. dope.. for micro film indoor and tissue covered models.. Old negitives an old jug or tin with a close fitting lid..add enough aceatone or lacquer thinner to just cover the negatives.

Stir a bit and cover, then put it in a cool corner away from any fires. Don't let the fire marshall inspect your shop or garage while your doing this.. It's highly explosive and burns great.

Don't tell anybody that I told ya, cause I'll deny it.

Oh, an stir and add acetone/l.thinner till you get rid of all the lumps and such, when thin enough the silver will settle out to the bottom and you can filter the clear dope out add a drop or so of banna oil to plasticise it then can/or bottle it.
Then sell the silver to a recycle center.

Not fuel proof...nuff said cause thats butarate.

JWN

My Feedback: (42)

Sig sells "dope thinner". They don't diffentiate between Butyrate and Nitrate as it's intended use. I've used it with both types and it works equally well with either one.

John

Strat2003

My Feedback: (1)

JWN, have you ever tried lacquer thinner with butyrate? I haven't actually tried it because my Scots ancestry prohibits me form wasting anything so precious as butyrate dope!

JWN

My Feedback: (42)

Nope, that's why I asked if dope thinner and denatured alcohol were the same. They certainly smell the same and if denatured alcohol is just a lower grade of thinner, then it will be fine for the initial coats of dope as well as cleaning brushes and guns. Hehe, my ancestry has nothing to do with it. I'm simply a tight wad who's always looking for a cheaper way

John

DaveP

John-
I really doubt that alcohol would be a suitable thinner (but hey, I haven't tried it!). And the hardware store lacquer thinner around here (Parks) won't cut butyrate either. I use MEK (Methyl Ethyl Ketone) or acetone to cut SIG nitrate and butyrate for initial coats and for cleaning. I use SIG's expensive thinner for spraying color coats, but a friend uses acetone and retarder to thin his. SIG thinner is approx $10 per quart - same as a gallon of MEK or acetone.

-Dave

Walter D

My Feedback: (16)

I only use butyrate dope (Sig's or Randolph) and any lacquer thinner will work just fine with them (they're probably the same), obviously, automotive good lacquer thinner with a slower evaporation rate would be best for spraying the final color coats, but for applying the base coats the nostril burning quality from Home Depot and or Lowe's would do just fine. I have never tried dope with other type of solvents but acetone will probably do it just as well, but I believe its evaporation rate is a little to fast.

Al Stein

I'd recommend you stay with the ketones (Acetone, MEK (Methyl-Ethyl Ketone), etc.) and organics as well. Alcohol is a water-based or at least water-loving substance and something about the idea of mixing water into dope leaves me a feeling uncomfortable.

About solvents like Acetone etc... you're likely to find that hotter solvents (i.e. the ones with lower flash point/faster evaporation like acetone vs. MEK) produce more shrinkage, give you less working time, and are more likely to blush. (Whether that's bad or good is situational... if you're tightening up the silk you just applied to a strong airframe that may be great... if you're looking for a perfect finish on a lightweight scale job, it could be disastrous.)

BTW, if you don't know what flash point means, find out before you use any of this stuff.

CurtD

My Feedback: (1)

Actually, a good grade of lacquer thinner works fine with butyrate. It does cause the butyrate to dry pretty fast so you probably will want to add some retarder, especially if you are painting in warm weather (above 80?). The finish on my Pitts M12 was done with Randolph and Certified nitrate and butyrate dopes from Aircraft Spruce's Griffin, GA store. I'm close enough (2 hours) to drive and get it.

Don't try to use any kind of alcohol-based thinners with dopes, either nitrate or butyrate. They won't mix and all you'll get is a big mess.

cal.45acp

hey guys, I've been searching for a alternate to dope, I am trying rust-oleum right now (thin with acetone), red devil used to make polyureathane in colors it was nitro-fuel proof (at least in the 10 to 15% range) and worked great but, I can no longer find in stores. All advice or experience will be appreciated Thanks cal.45acp

mikenlapaz

Any current tricks or suggestions on thinners for either of the dopes nitrate or butyrate?

Can butyrate be applied over painted surfaces? Water based - oil based - polyurthanes

beltmann

Hello everyone. I recently restored some u-control airplanes that had been in the garage for twenty-two years. No major problems other than punctures in silk and silkspan. Eight dollars for touchup dope is too steep. Enter wallmart. They sell cheap finger nail polish for eighty-five cents a bottle. Mix about fifty fifty with clear dope and thin with acetone for spraying. I have flown these airplanes all summer on ten to twenty five percent nitro with no problems. Dope is great because covering stays tight the life of the airplane.

makmov

My Feedback: (1)

Lacqure and Dope thinner are indeed the same.

A mix of



Isobutyl Isobutyrate

Acetone

Methanol

Toluene

Lactol Spirits (Solvent Naphtha Light Aromatic)

Cyclohexane

Heptane

Methyl Cyclohexane

Jim Thomerson

I bought a gallon cheap laccquer thinner at the hardware store. Did some spraying with Aerogloss clear, and tried to clean the gun with the laccquer thinner. Created a greyish gell and had to clean up with Aerogloss thinner. Aerogloss is not made any more and changed formulas several times over the years. So check out any dope/thinner combination on a test piece. The fingernail polish idea deserves some thought. I'm using Randolph and Certified clear dopes and some Sig and Aerogloss colors.

douglas racer

Trying to set a record for the oldest resurrection of a thread and get some advice at the same time, may I ask, is lacquer glow fuel proof? I soaked the firewall of my latest creation with lacquer rather than dope. Comments? Thanks.