Baking Enamels and Water slide decals

[jallenfuzz]

I have been baking my enamel paints and using water slide decals and finishing them with clear coat enamel.  Has anyone baked on an enamel after putting a decal on the pedal? Will this work ok or will it ruin the decal? Any advise will help.. Thanks

[R O Tiree]

In my experience (maybe I've been using the wrong stuff?) the decals go brown in the heat.

[jallenfuzz]

That's kinda what I thought might happen.  I wanted to get some feedback before I tried it.

[jallenfuzz]

Did you try an enamel clear coat over the sticker when it turned brown?

[R.G.]

RTFM

[GGBB]

I routinely bake the enamel clear coat after the decal is on without any problems - despite what the "manual" might indicate (which it usually doesn't).  The key is heat - don't go too hot - I set my toaster oven at 200F - the actual temp is probably lower.  Another thing that helps is to shield the enclosure from the element using aluminum foil (or in my case an old foil pie plate).

[jallenfuzz]

I'm not sure where this manual thing came from... Nothing I'm using came with a manual.. Anyway thanks, I think I'll give it a try.. With some foil

[R.G.]

Problems with multiple coats of paint are often caused by incomplete drying of underlying coats.

Bake the base layer at a very low temperature, not over about 170-200F (76-93C), until it's really got all the solvents out of it. Low and slow is best for baking non-catalyzed paints. Some enamels will be OK and even self-level somewhat if baked at higher temperatures, but this process has to be specified on the manufacturer's data on the paint.

Then put on decals. Let them dry very completely. They are composed of an underlying layer of either sugar or starch water soluble glue, the color printing, and an overcoat to carry the color. Commercial decals are color on top of the overcoat, print-them-yourself decals are color held by a top coat of clear. The layers are still there when they're applied. Any remaining water in the glue layer will blister or cause other issues if they're baked too fast either before or after another top coat. Leaving the item out in the noonday sun to heat gently and let the water diffuse out from the center of the glue layer is good, but a very mild oven can be used. Get the decals truly dry.

Then top coat. Clear enamel is better than lacquer, as the lacquer solvents will eat enamels. Again, air dry, then very gently drive the remaining solvents out with a low temperature bake.

Any browning is probably oxygen reacting with the top layer of the clear coat. Some enamels can take this, some can't. The can, if nothing else, should tell you the conditions to use the paint. The manufacturer ought to tell you the best ways to use their paint. If they don't, this tells you something about both the paint and the manufacturer.