Cracked Paint? How to do...

paraclete1 · Post by **paraclete1** » Sat Sep 10, 2011 10:40 am

I've been wanting to do a garage dio with painted weathered walls. I know that mixing two different types of paint, one over the other, can result is cracks and peeling, but I don't remember what the types were.

I'm sure I can search it on the internet, but I was wondering if anyone here has tried this already and if so, what did you use and how did it turn out? And do you have any pictures of the product?

Thanks in advance for any assistance.

irishtrek · Post by **irishtrek** » Sat Sep 10, 2011 2:30 pm

I take it you want to have cracks in your paint job?? If so then first paint with enamel paints followed by laquer paints before the first coat can cure all the way through.

paraclete1 · Post by **paraclete1** » Sat Sep 10, 2011 3:43 pm

Thanks, nothing I read said about doing it before it dried, but it makes total sense. That's a key piece of information.

irishtrek · Post by **irishtrek** » Sun Sep 11, 2011 3:23 pm

Back a few years ago I went and used a small can of light-medium blue enamel on my big PL refit and a couple of hours or so later I went and sprayed some acrylic laquer on the neck and in less than a minute the cracks appeard!!

photoguy · Post by **photoguy** » Sun Sep 11, 2011 3:48 pm

While I do not recommend Apple Barrel craft paint for airbrushing, they DO offer a Crackle Medium you can mix with your acrylic paint. Paint your base coat as normal, mix the medium with your second color, and as it dries, it shrinks and cracks apart revealing your original base coat.

paraclete1 · Post by **paraclete1** » Sun Sep 11, 2011 4:38 pm

I'll have to experiment with all this. Sounds like any of them might work for what I want to do. Thanks guys.

irishtrek · Post by **irishtrek** » Mon Sep 12, 2011 3:16 pm

You're welcome!!

eeun · Post by **eeun** » Tue Sep 27, 2011 11:41 am

I unintentionally achieved this effect by painting old Pactra acrylics over a thick coat of hairspray. I didn't let the hairspray dry much, which may have been a factor.

ajmadison · Post by **ajmadison** » Fri Sep 30, 2011 4:53 pm

Quick and dirty description about paints.

An enamel is a paint that cures from a chemical reaction allowing the tints in the paint to reach their final color. A lacquer is a paint that dries from the evaporation of the carrier. Because an enamel cures, it can be "stretchy." A lacquer becomes a monolithic layer and can actually contract somewhat as the carrier evaporates. Often (but not always) an acrylic paint is a lacquer, and enamels are petroleum based (like Testor's Model Master and Humbrols).

So most of the time, I've not wanted interactions between paint layers, so the conventional wisdom is to allow paint to thoroughly cure before applying the next layer, e.g. waiting between main paint finish and the application of weathering. IIRC, this meant waiting at least 3 days for a lacquer (usually an acrylic) and 5 days for an enamel (e.g. Model Master).

Usually, not following these rules causes cracking.