View Full Version : Coating Poster/Foam boards

07-31-2009, 09:42 PM
I'm trying to find a way to coat posterboard and foam boards so I can either waterproof/protect it or paint over it, whichever is easier. Any help would be appreciated, because I'm not the smartest arts n' crafts guy.

07-31-2009, 10:03 PM
waterproof or paint it... try clear enamel. Several coats of it should work wonders.

If you are using a hyper absorbent material, purchase a small can of thompsons wood sealer and apply a couple coats of that, then a coat of clear enamel. That should do what you want it to.

07-31-2009, 10:50 PM
Clear enamel... okay I've seen spray cans of that stuff but I thought it was only for wood and metal and such.

08-01-2009, 06:08 AM
If you're attempting to spray paint foamboard, make sure you use several coats of gesso or something similar before you do so. Otherwise, the spray paint will eat through the foamboard :/ Not a pretty picture, trust me. If you're on a tight budget, get a product called Mod Podge. It works as a base and a sealer and can be found for relatively cheap in simple arts and crafts stores.

08-01-2009, 11:47 AM
I'm guessing several coats are recommended for mod podge too. Ok thanks

11-02-2009, 03:57 PM
As Meitachi said, you could use gesso, or paper mache will work as well, I think. While I've never used gesso, paper mache tends to do basically the same job, only requires a bit more sanding afterwards to get that smooth surface... =) On the bright side, though, it can be made out of water and flour... xP Nice if you're on a tight budget like me... =)

11-02-2009, 06:08 PM
Just a word of advice: if you're going to use the paper mache method, know that using flour and water isn't always a good thing. If it's for a prop that you're not planning to keep for a long time, then by all means go for it. But, if it's something that you're planning to store for a longer period of time, the flour will grow mold. Bleagh, I know, but that's what happens if you use flour in making the 'glue'.

Amethyst Angel
11-02-2009, 10:29 PM
You can coat the foamboards with thin plastic styrene sheets. (You'll have to paint over it with enamel since acrylic won't stick to it well.) You can find more info on this method in my tutorial:


(Although all pics and links may not work well now since I'm transferring domain name and data right now. Sigh.)