Hi Bob,

The only problem that I know of in this case is if the Aerogloss hasn't gassed off.  Lacquers cure by evaporation (for lack of a better description) and if still gassing off, the Krylon *might* not adhere as well as it should.  I would describe the condition as getting bubbles of "gas" trapped under the Krylon, which wouldn't necessarily be noticeable to the eye.....  Krylon is a mechanical bond, the Aerogloss is a chemical bond.

Bill <><

You are aware that Krylon will turn into a gooey mess as soon as it gets any fuel or even exhaust oil on it. I have used Rustolium over dope (Brodak) several times without problems but I did let it dry for several days.

Bob,

to your Reply #2...

Epoxy cures as a chemical reaction. That's why we have two parts to mix together. Epoxy (and Polyester, which used to be popular - but MAN does it smell!) could cure under water, once the two components are mixed, and it skins over enough that water deosn't affect the surface. Epoxies combine into stuff that is chemically different from either the Hardener or Epoxy it started from.

Laquers are a plastic, or plastic-like, solid material that's dissolved in a solvent. The laquer dries as the solvent evaporates out of it. It doesn't go into a chemical reaction any more than salt or sugar dissolved in water does. You let the water evaporate out of a sugar or salt solution, you're right back to the same solid stuff. Ya, it might be clumped together, but it is the same chemical it was when you mixed it into water...

For solvent to 'gas off' from dope, remember the surface skins over pretty air and water tight in just a few hours at most. The solvent is pretty much trapped inside the surface, but it still works its way through and evaporates into the surrounding air. I've cut into doped models up to 20 years since after them, and still found a clear smell of the solvent!

You've probably seen articles mention to wait several weeks before buffing out a doped finish with rubbing compounds or whatever. As the solvent works its way out of the dope, the finish hardens. Most of the hardening takes place within a few weeks with most of our dope materials.

One of my buddies, Jerry Day, used Krylon Orange on his TF Tutor. With some care, it worked ok, but when he broke it, and needed to patch the silkspan, the troubles started. Clear dope to apply a patch to the wing caused wrinkling of the Krylon. He ended up spraying some Krylon into a jar, and using that to apply the patch dry, which worked fine. After drying, then water shrink. I don't know what the next step was, but possibly he used clear Krylon to start, or clear dope. Personally, I'd avoid Krylon.

Another buddy, Mike Haverly, has been using various dopes (Certified, Randolph, SIG, and Brodak) with Dupli-Color color spraycans from the auto parts stores. Under or over, no problems. Lots of colors available in Dupli-Color, too. Most recently, he's started using 2 part automotive clearcoat for the topcoat.  Steve

As to the Duplicolor Automotive Lacquer:  My son, Aaron's, last trwo planes have been totally color painted with Duplicolor over whatever substrate we used at the time.  Mostly Sig Nitrate, Duplicolor filler/primer and then the Duplicolor colors.  Topped off with NAPA Econo 2 part clear.  One is a Satana the other is an Oriental.  No problems after a year or more!

I also used the Duplicolor "Metal Cast" paints (lacquers) to do a Candy Apple Red finish on my Tomahawk.  Aaron did a power on inverted landing (not his fault!) which tore a little covering and knocked off the fin/rudder.  Used Sig Lite coat to apply the patches, reprimed, and finished like original, no problems.

YMMV!

Bill, is that automotive Duplicolor fuelproof by itself?

Seems to be a *little*, but I haven't trusted it altogether.  I used it without protection on the fuel tank of the Tomahawk.  It hasn't "come off", but my fingers got some red on them one time!

Funny you mention Duplicolour paint Big Bear.  Tonight I was standing in an Autozone store, wondering if the Duplicolor Grey primer/filler was a lacquer based primer suitable for stunt use.  Was looking for the Sherwin Williams primer but neither Advance nor Autozone carry it around these parts.  I guess looking at Napa is next on the list.


Steve

Hi Steve,

The "standard" Duplicolor is lacquer.  They make big cans of Acrylic Enamel, but the label is different, and it says Acrylic Enamel ingood sized letters on the front.  Otherwise it is lacquer.

All their primers (AFAIK!) are lacquer based.

Sig Lite Coat will go over Dulpicolor with no problems.  This allows infinite trim color options if you're doing a dope finish!

Bill <><