People mostly got this wrong, but Styrofoam is a brand name for an expanded polystyrene, a petroleum-based plastic that is made up from styrene monomers. So, for people who are a bit of a “perfectionist” themselves, you can call it EPS foam, instead of Styrofoam.
But I guess, due to its perfect marketing strategy and how they advertised their product, it is now accepted by society to be called Styrofoam.
If you are having trouble picturing it, just think of it as a lightweight white colored thing that floats in water and is one of the perfect alternatives for making artificial snow.
Since styrofoam is originally white in color, people somehow paint it and oftentimes use it as props. However, painting a styrofoam can be quite tricky. Just an additional information, paints and coatings mostly contain acetone or solvents such as benzene, toluene, and tetrahydrofuran which are things that dissolve polystyrene, making it lose its original structure. Styrofoam is actually 98% air, so when it dissolves, all the air inside escapes, making the foam to almost nothing.
Rest assured that in this article, we’ll teach you on how to paint your EPS foam perfectly so you can use it to whatever you like and it won’t dissolve to nothing.
Uses of EPS Foam
First off, let’s discuss the uses of it and why using it is somehow important. If you are in the food industry, you would know that EPS foam is a good food packaging. It holds the heat in and it’s a good way to evenly portion the food that is supposed to be served.
Also, in the construction company, it serves as a cushion for things that have edged corners. Due to its resistance to impact, EPS foam became one of the most useful protective packaging. Like any other plastics, EPS foam can be molded to whatever your imagination is, making it versatile.
How to paint styrofoam for craft projects
If you are planning to use EPS foam to create your perfect crafts, use acrylic paints as it will not dissolve the styrofoam and it does stick well to the EPS foam. Acrylic paints are actually not that hard to find. They are mostly sold to any paint store and you can even buy them online. So the possibility of buying this is easy. You can also buy them in small quantities which makes buying it efficient.
If you can find any craft stores in your local area, you can buy several branded regular craft sealants. Buy a couple of these as they will be important in painting your EPS foams. Apply the sealant first to the styrofoam area where you wanted to paint. You can use whatever brush you have. Apply a small amount consistently from time to time to get an even finish on the surface where you wanted to apply paint. Let the sealant dry first before applying any paint to avoid any certain damages. If it’s dried already, you can then use your paint brushes to apply the first coating of the color you want. A foam sponge, foam brush, or any paint brush that has a soft-bristle are the perfect ones to use. After applying the first coating, let it dry completely before applying the second coating. Usually, it does take 20-25 minutes before it will be considered completely dry.
This type of painting styrofoam is used for personal crafts and for DIY purposes, so it does not apply to industrial or commercial approaches. For industrial approaches, the EPS foam requires a hard coating so that preferred paint can then be freely applied.
Rigid hard coating for EPS foam
If you did not know, EPS foam coatings are actually manufactured industrially. There are actually a lot of solutions that are in the form of a two-component, semi-rigid, 100% solids, polyurethane polyurea hard coating. These are applied as sprays to accommodate reaching hard-to-reach surfaces, which these solutions are commonly applied.
Primer for the rigid hard coating
Like any other coating, a primer is a must before applying the coating.
In the primer’s case for the hard coating that was mentioned earlier, the water-based acrylic latex rubber coating is a perfect primer as it is formulated to completely dry faster than any other primer.
The primer does a couple of things to the EPS foam that is why it is considered the perfect partner for it, like limiting the air bubbles in the hard coating and restricting air bubbles to escape from the EPS foam surfaces. You can actually check reviews on different sites on people who have tried it.
Do you need to use both the primer and rigid hard coating?
If you want to have a smooth surface, then the primer is a must. In any other cases, using the Rigid Hard Coating will be fine on its own and will do a satisfactory job.
One of the advantages of using a primer is its flexibility over different ranges of temperatures, since it can perform well on sub-zero temperatures and it also has high tensile strength.
Long Lasting Solutions
Considering you wanted your crafts or EPS foam to last longer, it is a must to follow the manufacturer’s instructions. For example, for a primer, you need at least a minimum thickness of 7 mm wet or a 6 mm dry. By following this instruction, you can achieve the maximum benefit from its tear strength and tensile strength properties.
Keep in mind also that the primer also needs sufficient time to dry off before you can spray on the rigid hard coating. For the cure time of the primer, you might need 24 hours at a 72 degree fahrenheit to achieve its best result. In high humidity conditions or cooler temperatures, or even a thick film of primer, you do need a longer time to cure.
For the rigid hard coating, you do need 20 and 30 minutes to set it. Once you have done it, you can then apply the paint you want to bond with the EPS foam.
Assuming you have followed every instruction from the manufacturer and have reviewed every tutorial on how to do it, then I believe you’re ready to go and do your DIY crafts. So what are you waiting for? Go on and buy those materials.