Zor

I am now all confused.
I understood it was the addition of the thinner that causedyour dope to gel.

Zor

byjoe

My Feedback: (3)

You are right. I found that after it gelled(about 40% did)I put the gel in a jar with acetone. The acetone dissolved the gel,I then poured it back in the 50/50 jar and it was fine to use.I now use acetone too thin the nitrate ,then add Sig thinner with no problem.

smithcreek

My Feedback: (25)

Interesting. I can't imagine what went wrong using both sig products. I've used both in the past. I wonder if it's possible they mislabled some thinner and shipped it out? By the way, Randolph nitrate thinner works well with sig nitrate dope. Available from Aircraft Spruce, costs much less.

buzzard bait

What TFF said about thinners is correct. I don't understand why Sig thinner should have been a problem for any kind of dope. I'm not surprised that a little acetone solved the problem.

Nitrate can be thinned with cheap thinners, like lacquer thinner. Butyrate needs some more expensive solvents in the thinner. The reason we use butyrate on models is usually for fuel proofing. Butyrate is harder to dissolve. If it dissolved in cheap thinner then it would dissolve in fuel too. But a thinner formulated for butyrate will also work for nitrate. The reason Randolf sells two kinds is probably because the nitrate thinner is cheaper, so why use expensive thinner when you're putting down nitrate?

By the way, if you are trying to fix up a really old plane, my experience is you can use anything on top of an old finish. I've even put nitrate on top of old Aerogloss, to do a patch, but it was originally painted in 1966. I think the compatibility problems arise because it actually takes years for butyrate to completely off-gas. Before that happens, you can't put anything but butyrate over butyrate.

Jim

buzzard bait

Also, the link I posted a year ago on this thread giving a source for colored NITRATE dope still works. Here it is again...

http://www.freeflightmodels.com/index.html

Zor, I bought mine from them many years ago, but not the 1950s. Probably the early 90s. The current website still lists it. This is for pigmented nitrate dope, not dyed. Aerodyne has always been a good company in my experience, so check with them if you are looking for colored nitrate. They don't list it in the usual "Tennessee Red" or "Miami Blue" colors, just red, blue, green, etc. Maybe they get pigments and mix themselves.

Jim

Zor

I do not see anything about colored nitrate dope at that link.
The link seem to open a site from the year 2004.

Zor

buzzard bait

Checked the link again and saw nothing about 2004. Clicked on Building Supplies at the top of the page, then Paints and Related Products, and the colored nitrate is the first thing listed, with all the colors they carry. I did that just now.

The home page lists an email address, [email protected]

Why not just write to them? If they are still in operation you'll get an answer. I had good dealings with the Heinrichs in the past, but it's been awhile.

Jim

byjoe

My Feedback: (3)

I plan to use Rustoleum primer over the nitrate and Rustoleum paint. I found acetone cleans brushes better than thinner.

Zor

Hello Jim,

I have no reason to write to them.

I thought the link was going direct to the dope page(s).

I have covered all my models with fabric and dope and I do not need any colored nitrate.

I findit interesting that their butyrate only shows clear dope.
It makes me wonder if they have simply mixed up the two words one for the other.

People like Leaven's Brothers, suppliers to the full size airplane refinishers, have nitrate only in clear and the butyrate in many colors. They will even make a colorto match a sample.

Zor

buzzard bait

No, it's not a mix up. It's a small family business. They aren't trying to compete with Sig. They fill a small niche and that's all they are trying to do.

makmov

My Feedback: (1)

Bit strange they make colored Nitrate and clear Butyrate, usually it is the other way around. It does seem odd. Not that there isn't colored Nitrate dope but it is very rare and limited in color choices, Nitrate is almost always clear.

Wagon1

Just wanted to toss out my experience with Brodak. Called in my order, and had my dope two days later. $8 for the 4 oz bottles. Hard to beat.

summerwind

Jim,
thx for posting the link to Aerodyne............i forgot all about them.
few people realize the value in being able to buy colored nitrate..........colored butyrate is as common as McDonalds, but never do you find colored nitrate.

buzzard bait

You're very welcome Mike...and now as a confirmed free flighter I imagine you might be using them!

I was glad to find it years ago. One thing I think is nice is the aluminum nitrate, which you can use as a UV resistant base coat for anything. Maybe with nitrate white on top, and then paint anything else over it.

As far as the other colors, I haven't used any since I was a kid. I guess the advantage is it goes on nicer than butyrate and doesn't take a decade or two to stop shrinking. I know diesel guys liked them. Fernando Ramos used to talk about it in Model Builder. Maybe when I build an old time glider some day I'll use their colored nitrate.

Nice to hear from you. From the other comments, you'd think I was telling people the sun was going to rise in the west the next day!

Jim

summerwind

Nitrate doesn't fade things either like Butyrate. now if someone would just bring back the Aero Gloss fuel proofer for sealing nitrate, life would be good.

smithcreek

My Feedback: (25)

Could you use aluminum nitrate to fill the weave instead of clear?

buzzard bait

SC, I'm not sure if it would be a good idea to try that, but I think you mean "seal" not "fill". People who know way more about paint than I do distinguish between "filling" and "sealing". So first off, clear will seal the weave, but it does not really fill the weave. Or at least it would be a very slow way to do it. That's why some people add talc to dope...to fill grain or weave. There are other fillers people use.

As for sealing, it takes a few coats to do that, depending on the material. But it only takes one or two of the silver to make a base for color coats. So you start with clear and then switch to silver.

By the way, a lot of recommendations say to put white over silver before switching to other colors. I have noticed that putting red directly over silver cause the red to look dark.

Bottom line is start with clear. The final coats will be the desired color, possibly with clear coat last. In between, some people like silver and then white, and my only point is that those can be nitrate.

Jim

smithcreek

My Feedback: (25)

I do almost all my models in fabric and paint, so I'm always looking to keep it light. I only "fill" the weave where I'm looking for a smooth surface to simulate metal. Otherwise I just "seal" and put on as little paint as possible. I'll have to get some silver nitrate and give it a try as the initial nitrate "seal" some time.

From what I understand the two colors that absolutely must have a white base are yellow and red dopes. They are transluscent and without the base of white take many coats to cover. The first time I used red I did not know this. I had penciled "R" and "L" on my elevator halves during construction assuming the paint would cover them. It took about 6-7 heavy coats of red to finally cover enough so they didn't show through. Made the plane tail heavy.

buzzard bait

I do the same thing...seal but only fill where I want a metal look.

That makes sense about red and yellow. I remember painting clear doped wood with red and I couldn't believe how many coats it took.

I remember that Aero Gloss Fuel Proofer too. I wonder what it was.

Jim

Blue Baron 29

Hi, Speaking of Fernando Ramos, does anyone know how to contact the former writer for, "Model Builder", magazine? Thanks, Mike

buzzard bait

No idea, but Bill Northrup might know...

http://www.geocities.com/aerohydro/mfm/northrop.htm