There are quite a few different ways to seal EVA Foam but depending on your specific project the way, that you want to seal EVA Foam may change quite a bit. So after reading this article, you will know how to seal your EVA Foam and how to decide which method to use.
So how do you seal EVA Foam? In short, there are a lot of different ways to seal EVA Foam the two most well known and widely used methods are using either Plasti Dip or White Crafts glue (wood glue) to Seal EVA Foam. The White Crafts glue can simply be applied to the Foam in multiple Layers, if necessary, and it will Seal EVA Foam enough to be painted. Plast Dip seals EVA Foam much better but is also a little more complicated to apply.
How to use White Crafts Glue (Wood Glue) to Seal EVA Foam?
Probably the easiest way to seal EVA Foam is using White Crafts glue or wood glue (its almost the same).
You can get wood glue, white crafts glue, or an other alternative to wood glue from any crafts store. White craft glue includes Mod Podge, wood glue, PVA glue, and more. The glue dries transparent and seals the Foam underneath well enough so that you can paint it.
To seal EVA Foam with white glue simply use a brush to apply the glue on your foam project. Try to cover every part of the foam. Don´t worry about the white color the glue will dry transparent.
You don´t have to apply the glue very thick. Just start with a thin layer and if you feel like the first layer wasn´t enough simply add another layer after the first layer has dried.
Once you have covered every inch of your foam let it dry for a few hours.
Once the glue has dried you can easily start painting it as you like. Depending on the color, that you are using, it may not stick to the glue seal so you may have to use a primer before painting the foam. But most colors will stick to the glue seal without any problem.
This method is probably the easiest method to use and it will work well for most projects. But you have to seal the foam after you painted it or your paint job may suffer.
The only big drawback when using this method is that the foam can wrinkle when it is being deformed in any way. So if the Foam is being bent or twisted then wrinkles can appear on the surface of the foam and it will almost impossible to get rid of these wrinkles. So I would recommend using this method only on pieces, that will never be deformed in any way.
How to Use Plasti Dip on EVA Foam?
The short answer is yes, you can use Plasti Dip on EVA Foam. It is a very good way to seal your EVA Foam project. EVA Foam, that has been sealed with Plasti Dip, is very robust and water-resistant. Most Prop makers and Cosplayers use Plasti Dip to seal their projects because of its reliability and robust seal.
I almost always use Plasti Dip to seal my projects.
It is, in my opinion, the best way to seal EVA Foam but it is also a little more complicated to do.
You can buy Plasti Dip in every hardware store or car repair shop. Plasti Dip is sold in spray cans but you can’t simply spray the Plasti Dip out of the box.
Before you use Plasti Dip you first have to heat up the can. But don´t put it in the oven! Simply get a pot and heat some water on your kitchen stove until the water is boiling hot. Then remove the water from the stove and wait for about a minute. The water will now be hot but not boiling anymore. You can also hold it under the hot water tap for a few minutes instead.
Now put the Plasti Dip can in the hot water and let it sit in there for about 5 minutes.
Before you apply the Plasti Dip on the Foam surface you should heat seal the surface. You don´t have to do this but it is good practice.
Then shake the can very well and carefully apply the Plasti Dip layer by layer to the foam.
Try to only spray Plasti Dip in a well-ventilated area or outside! It is slightly toxic and you should not breathe in any of the fumes.
Here is a very helpful video on how to Seal EVA Foam with plastic dip form Kamui Cosplay if you are interested.
The awesome thing about sealing EVA Foam with Plasti Dip is, that you can use it for any kind of Foam project. It doesn´t matter if you squeeze it, bend it, twist it or if you deform it in any other way.
If you see wrinkles appearing on the surface on your project as a result of being bend or squeezed, then you can simply hold a heat gun or a hairdryer to the surface of the foam and the wrinkles will disappear.
Do You Need to Seal EVA Foam?
In short, it is not necessary to seal EVA Foam. But sealing EVA Foam will protect it much better from damage, water, paint chipping, and more. So it is recommended to seal EVA Foam with either Plasti Dip or White Crafts glue.
I had a lot of projects, where I didn´t seal my EVA Foam and it was just fine. But those where primarily projects, where the foam was stationary or only decoration on a bigger prob. So the Foam would not be moved, deformed, or something similar.
But if you use EVA Foam for a costume or a prob, that will be carried around and may even fall to the ground a couple of times, then I would highly recommend sealing your foam.
Sealing it will protect your Foam from damage, paint chipping, and more.
I would highly recommend sealing your foam with Plasti Dip if the foam can be bend or deformed or with white glue if your foam is mostly solid.
How Do You Seal EVA Foam After Painting?
In short, if the EVA Foam was sealed with Plasti Dip or with White Glue before it was painted, then it does not have to be sealed afterward. The paint will stay on pretty well. But if the Foam was not sealed before it was painted then it should be sealed with a clear coat. A clear matt acrylic sealer or matt varnish will be more than enough to protect the paint job.
Sealing EVA Foam is quite important so you should seal it one way or the other.
I personally either seal the Foam with Plasti Dip before painting it. This will let the paint stick very well to the Prop and it will protect the foam from almost everything, that you can throw at it.
Or I paint the Foam directly and then I seal it after painting with a layer of clear matt coat or with a layer of matt varnish.
Matt varnish will make the prob water-resistant but it will also make the prop quite rigid. That is why varnish is only good when the Foam Prop is not being twisted or deformed.
How Do You Harden EVA Foam?
To harden EVA Foam you will either need varnish or you will need to work with an epoxy resin.
Varnish is normally used to seal wood. It drys rigid and transparent.
You can get varnish in matt or in gloss. So depending on your project you can choose either one. I usually prefer matt varnish because it fits most of my projects best but the choice is really up to you.
You can buy varnish in any hardware store.
Apply the varnish with a brush to your EVA foam. Try to cover every corner and don´t use too much varnish. A small layer will be more than enough. Once you are done applying it leave it to dry for a couple of hours. Depending on the kind of varnish, that you used, the drying time will vary slightly.
Once the varnish has dried your Foamr Project will be rigid. But if you apply enough force the varnish will eventually crack under the pressure. So if you want to make your EVA foam really hard, then I would suggest using Epoxy resin.
Epoxy resin is a two-component mix, that has to be mixed in a ration of one to one. You need to buy a transparent epoxy! So read the label of the epoxy carefully before buying it.
Once you have mixed your epoxy simply apply it evenly to your EVA Foam and try to spread it with a brush.
Only use Epoxy in a well-ventilated area or outside because it is slightly toxic and the fumes are not very healthy.
Leave the epoxy to dry overnight and once it has dried your Foam prop will be very hard and robust. The hardest part is getting an even coat of epoxy on your prop. It is not easy to work with epoxy and because it is slightly toxic you should also only use it with a mask and some protective gloves.
But if you want a really really hard prop, then epoxy resin is the way to go!