EVA & Other Foams

EVA & Other Foams

Is EVA foam the same as craft foam? What about "fun foam"?

Yes, craft foam or "fun foam" sheets ("Foamies" is a craft foam brand name) is EVA foam. "Puzzle mat" tiles often sold for garage and playroom floors are generally EVA foam (although some brands have a plasticized layer on the outside that make them unsuitable for crafting).

Can you paint EVA foam?

Yes! Many different types of paint and pigment will adhere to EVA foam.

However it is best to prime or heat-seal EVA foam before painting otherwise the foam will soak in more paint than needed, resulting in a spotty finish and a lot of wasted time and material.
Heat-sealing can be done with a heat gun. This will cause the cells in EVA to shrink and tighten, making it less likely to soak up paint. CAUTION: Too much heat will cause the foam to shrink visibly and harden/burn.

EVA is often primed with materials such as Plastidip, Flexbond, and sometimes even white glue.

How do you smooth EVA foam?

There are several different ways to smooth EVA. The first thing is to be as careful as possible when joining edges. Seams can almost disappear if attached slowly and carefully.

Ragged edges can be sanded and shaped with the sanding drum on a rotary tool.
Gaps can be filled in with Foam Clay or thickened Flexbond.

Smoothing large areas can be done by heat-sealing with a heat gun (heat-sealing will cause some shrinkage of the piece), covering the foam with a thermoplastic such as Worbla, or priming with several coats of a primer such as Flexbond or Plastidip

How do you shape foam?

Foam can generally be shaped using a heat gun. Warm the area that you need to shape, making sure that the foam doesn’t get too hot and melt. Then shape the foam to the desired form and hold it there until the foam cools. You may need to repeat this several times to realize complex shapes. Always remember to wear heat-resistant gloves when handling the hot EVA foam. Heat shaping EVA will cause the pieces to shrink and harden to a certain degree.

Heat shaping L200 will cause L200 to expand and become softer.

How strong is EVA and other foams?

The strength depends on the thickness, shore hardness, and density. Daley Kreations carries two types of EVA foam; Hard-lite and Form-lite. Hard-lite EVAfoam has a shore hardness of 60 and a density of 200kg/m³. Form lite EVA foam has a shore hardness of 45, and a density of 125kg/m³. L200 foam is generally much softer and more prone to tearing than EVA foam.

What is the difference between Form-Lite and Hard-Lite EVA Foam?

Hard-lite EVA foam has a shore hardness of 60 and a density of 200kg/m³. This makes Hard-lite more suitable for durable props and making very sharp and angular details. The higher density is also excellent for shaping with a rotary tool such as a Dremel. 10mm thick Hard-Lite feels comparable to wood. Form lite EVA foam has a shore hardness of 45, and a density of 125kg/m³. This makes form-lite the better choice for complex curves and pieces that need to remain slightly flexible such as body armour. Form-Lite is comparable to the density of "fun foam" sheets and floor tiles.

What is the difference between L200 and EVA foam?

L200 is a closed cell foam similar to EVA. It has a long history of use in the SFX and movie industry. It tends to come in larger sheets than EVA, however it is softer and more prone to tearing. This can make it ideal for breast plates or abdominal plates that may need to flex to remain comfortable to wear. It can be covered in thermoplastic, shaped, primed and painted in a very similar manner to EVA foam.

The biggest difference between L200 and EVA is that EVA shrinks when heated and L200 expands. Therefore a common trick in EVA foam smithing such as cutting a line and then using heat to cause the cut to expand and look machined will NOT work with L200. Cuts or scratches in L200 can actually be sealed with heat.

Do I need special tools to cut foam?

No! A snap-blade style box cutter and scissors are all you need to cut either EVA or L200 foam. The scissors are best used on thinner foam sheets (1mm-3mm) and the box cutter is best used for the thicker foam sheets (4mm-10mm). Cutting foam will dull any blade or scissor quicker than normal (make sure you’re not using your fabric scissors!). They will still cut paper, cardboard, etc just fine - but it's best to keep a large stack of blades on hand when cutting foam and to switch them out frequently.

A hand-held sharpener is very helpful for extending the life of your foam cutting blades or scissors.