Styrofoam is an easily crafted material that you can use traditional wood working tools on to shape and mold to achieve nicely detailed sculptures. Unfortunately, it’s also fragile with small pieces easily broken from even a moderate amount of pressure. To add a level of protection to finished Styrofoam creations you need to coat the material with a thin hard coating. Once dried the coating creates a shell that adds strength to the Styrofoam, keeping it from harm due to normal wear and tear. Though there are several protective coatings available on the market, you can DIY a coating yourself using latex primer and joint compound.
Things You'll Need
- Latex primer
- Plaster joint compound
- Cup or small bucket
- Wooden stirrer
- Fine-grit sandpaper
- Tack cloth
Mix a latex primer and plaster joint compound together in a cup or small bucket depending on amount needed for coverage, using equal portions of each. Mix the two thoroughly with a wooden stirrer to for two to three minutes until you have a coating that you can brush over the Styrofoam.
Test the mix on a scrap piece of foam by brushing a thin layer of the material over the foam with a paintbrush. Watch the foam for about five minutes, looking for signs of melting. If the foam remains whole, then the mixture is safe to use on the foam object that you intend to cover.
Brush the mix over your Styrofoam object using the paintbrush for even coverage. Cover any portion of the Styrofoam that you wish to add a hard protective cover to. Allow the coating to dry for about two hours.
Sand the hard coating using fine-grit sandpaper to remove any of the brush stroke marks left form applying the mixture. Wipe clear with a tack cloth and finish as desired. The coating takes a water-based paint easily, acting as a primer for the Styrofoam.
Tips & Warnings
- Substitute some latex caulking for the joint compound to add flexibility to the mixture.
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