I want to build a wood kit using acrylic paints. I know there's something you can put on the wood first to act as a "shield" to prevent it from warping, but what is it? Also is there an acrylic paint I can use to represent old, gray, rotting wood?
You can paint all the surfaces and then press the items between wax paper. If you only paint the 'exterior' surfaces, you'll almost certainly get warping. You can also seal the items first with varathane or urethane, and then paint them. You can also use wood sealers prior to painting.
So would Thompson's Wood sealer work? It is quite thin and looks like it could be applied with a simple spritzer or sprayer.
If you're going to use Inida Ink wash, then you don't need a sealers. Your best bet is just lots of interior bracing. Superglue thick strips vertical to the grain and you should be fine. The wood will warp in a few places initially when you apply the stain, but will dry flat. Here's an example of a building I scratchbuilt 20 years ago, no sealer needed. Just India Ink wash and lots of bracing:
Lots of bracing will prevent it from warping. I learned this early on with wood kits.... brace where it won't show.
