Polyurethane dilema

I use the Deft brand of Lacquer based poly U. Works great.

I use long setting epoxy, thinned with a little alcohol.

Ed, I use Minwax Poly U for my glow engines. But I used thinned expoy for my gas engine.

On 8/21/2003 5:17 PM Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

Poly urethane IS NOT FUEL PROOF - it is FUEL RESISTANT. Poly is USUALLY good to about 15% nitro. For GASOLINE engines, many people just use latex paint with water base poly.

According to the Minwax technical support folks their polu urethane (both water based and oil bsaed) is NOT resistant to gasoline. Ed

I've had polyu slough off after being soaked with fuel (line fell off).. back to epoxy.

Sure sounds like its time to head for the automotive paint supplier and look into a two part clear cote. Take something already painted with you and I bet they will spend all the time needed to chase down what you need. It may be a little more expensive, but, it's a little late to be concerned about price.

JR

You have to be careful using a generic term like polyurethane. Although they have similar charcteristics, the single part and multi part versions are very different. A catalyzed polyurethane will be VERY gasoline proof. Same with two part acrylics.

How does one get gasoline on their model anyway? Be careful!

Ed Cregger

And very deadly, if sprayed without using a "forced air, fresh air" breathing system. It will attack the liver, and the effects are irreversible.

FYI: I just ran a test today. I painted Minwax oil-based Polyurethane on a piece of wood yesterday and let it dry over night. This morning I put some gas oil mix (50:1) on it and let it sit for 5 minutes before wiping it off. The Polyurethane held up fine.

What I was referring to was the dangers of the paints. Occasional use, like once a year, isn't all that harmful if done with good ventilation.

It will be even better if it is allowed to fully cure for about 3-4 days.

Agreed

Everybody, don't listen to Paul. Bad advise. Use all the correct procedures when dealing with poly paint. It is not worth one minute of shorter life.

And even better with a second coat.

And don't smoke, drink, drive a car, ear meat, walk down the street, or any other hazardous activity. There are so many things we do that will kill us so much more often. Oh, and don't fly model airplanes! That is dangerous, too!

So you don't have any problem with inhaling Cyanide? O.K., go ahead. That is what you are getting, with multi part Poly paint. Me, I try to avoid one of the most powerful toxins.

I'll bet you was your hands with MEK, also.

Everyone else out there that has a brain, stay away from breathing that stuff. It only costs about 20 bucks to rig a fresh air mask; money well spent.