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wierd interaction of decal solvents and enamels

Posted: February 3rd, 2017, 2:09 pm
by rob_van_riel
I thought that enamels were pretty much impervious to decal solvents, since the latter have been described with fair precision as "glorified alcohol" (it's a bit more complex, but who cares). However, I've had two cases in the past week of enamels being damaged this way.

The first was Humbrol gloss black, which went all crackly after a generous application of MrMarkSofter. That's one of the hotter solvents, so I shrugged it off, but a few days later, XtraColor turned matt after being exposed to Microsol. Still thinking alcohol and enamels didn't interact, I mistook the matting for residue, and tried to wipe it off with 70% ethanol, which exposed the underlying primer :shock:

To make things extra wierd, this self same bottle of Microsol had never caused trouble in the past that I'm aware of (I might have missed something, of course).

Now that I'm aware of this, the next question of course is what to do about it. Do I need to wait more than a few days for the enamels to cure? Multiple layers of paint to build up a thicker, stronger layer of paint (and no miniscule gaps in the coat for the solvent to seep under)? Is there something that can be used as a barrier coat?

Help?

Re: wierd interaction of decal solvents and enamels

Posted: February 3rd, 2017, 3:03 pm
by 59North
Hi Rob. Indeed, I have also experienced the frustration of having decal solution 'melt' the enamel paint coat, or at least, stain the paint.
My solution to the problem, was to not let the solution pool. I only use Walthers Solvaset (hot), brushing it gently on the decal only. I'll leave it on for a few seconds, and then use a cotton bud to even more gently blot the pooled solution up. Once done, the solution must be left alone until completely dry. Procedure repeats are most likely. This is the technique I used on my recent P-26 build, which had a complicated decal scheme.
I also let the final enamel coats set properly with time, which usually means 24+ hours.

Re: wierd interaction of decal solvents and enamels

Posted: February 3rd, 2017, 3:14 pm
by rob_van_riel
59North wrote:My solution to the problem, was to not let the solution pool. I only use Walthers Solvaset (hot), brushing it gently on the decal only. I'll leave it on for a few seconds, and then use a cotton bud to even more gently blot the pooled solution up. Once done, the solution must be left alone until completely dry. Procedure repeats are most likely.
I'll give that a try, see where it goes.
I don't intentionally let the solvents pool, especially not away from the decals, but non-level surfaces and gravity tend to conspire against me in this respect :roll:
I also let the final enamel coats set properly with time, which usually means 24+ hours.
I tend to measure curing time in days rather than hours, with a whole day the bare minimum, so I'll probably be exeeding your drying times as a matter of course.