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Michael Dobony wrote:
On Sun, 22 Feb 2009 13:24:53 -0500, wrote:

Michael Dobony wrote:
On Sat, 21 Feb 2009 17:25:51 -0500, wrote:

Michael Dobony wrote:
On Sat, 21 Feb 2009 12:41:25 -0500, Ed Pawlowski wrote:

"Michael Dobony" wrote in message
.. .
We are trying to paint some pinewood derby cars with Kryon paint. If we
let the paint set for over 24 hours we get an alligator finish on the
cars.
Any idea what is happening here?

Mike D.
Depends on the particular formula, but it is often better to repaint either
before or after after some specified curing time. What does the can say?

One can I just looked at says "Recoat before 24 hours or after 7 days"
Another says recoat any time.

Also., putting on coats too heavy makes it worse.
We are doing light coats and it says to recoat within 1 hour or after 24
hours. There is no problem with doing the recoat within 1 hour. The
problem is when waiting for more that 24 hours. This is on top of 2-3
light coats of primer.
Any chance the primer was not cured? Dried paint in hot sun?
Yes, the paint was dried in the hot sun. That might be the problem. Why
would this cause problems? It seems that it should dry faster and harder
in the sun and give a better finish.
That is almost surely your problem. The surface dries hard (too
fast)and doesn't allow evap. of the solvents underneath.

This would explain a layer dried in the sun, but doesn't explain why a
second layer would instantly bubble up before being put in the sun.

The top layer formed a skin, then the solvents trapped in the earlier
layer expanded but couldn't pass through the dry skin.

SOP is to paint each side of a house before/after the hottest sun
exposure, for the same reason. Temp guidelines on paint labels are
there for good reasons - too cold, it won't cure; too hot, the surface
is complete but traps the lower solvents.