Working with Foam: Part 1

Part One: The Basics

Hello there!  My name is Ryan, and I am the brains behind Buster Costumes and Props.  I want to take you on a journey through the exciting world of foam building!  From where to get foam, what tools you’ll need, all the way through assembly and finishing.  I am by no means an expert, but I hope that sharing some of the knowledge I have gained through trial and error will help you in your crafting exploits.

Foam Types and Where to Purchase

Since this is on the KC Cosplay page, I am going to plug a local business that we are very lucky to have.  That business is AM Foam.  They are located in Kansas City, Kansas and are a large foam and rubber warehouse.  I have been using their cross-link foam and it is definitely my favorite foam that I have worked with.  Besides the quality of the foam, the other big advantage is that if you are local to Kansas City, you can go pick it up, so there is no reason to pay the outrageous shipping charges that accompany buying the large rolls online.

Keep in mind too, you will need to know what thickness of foam you need for your project.  I use 1/4″ for most of my armor and helmet projects, however on some of the larger scale foam projects I have coming up, I am using 3/8″.  If you are building something that needs to be more durable, like a shield for example, a thicker foam is recommended.

Note: much of this is simply my opinion from having worked with these types of foam before.  Your experiences may vary.

Polyethylene Cross-Link: 

This is the foam I enjoy working with the most.  The main thing I notice working with this versus L200 is it seems to be more durable even at the same thickness.  Holding the two side by side, you can feel a difference.  The one downside that I would say is that the polyethylene cross-link requires more heat to get to a point where it can be shaped.  Not a big deal really, simply a difference.  You can purchase this type of foam at AM Foam in Kansas City, Kansas in various thicknesses.



L200 is another type of cross-link foam that is very popular with builders.  It’s very similar to the foam available at AM Foam; however, just in a “feel” type test, there is a difference, which I described above.  This foam is available many places online. I ordered mine from, as they offer free shipping on orders over $75.  Shipping costs on foam can be outrageous, since they come in quite large rolls, so free shipping is a nice perk.


Foam Puzzle Mats:

Foam puzzle mats are a fairly cheap and much more widely available option, so they are very popular with builders.  They are generally thicker than I like to work with, and as such, they are more difficult to get nice, clean cuts through, as well as being harder to heat and shape.  It is great for making weapons and other items that need substantially more durability. Generally, it also has a “diamond plate” type texture on one side.  These mats can be found at many places, but they are usually cheapest at Wal-Mart and Harbor Freight.  I didn’t have any laying around so this is a stock picture of what they look like.


Equipment Mats:

I have never worked with these, so I can’t comment on the ease of use.  From what I have seen, they are thinner than the puzzle mats and have a texture that is much more interesting looking.  I have seen it used by Mass Effect armor builders specifically, as it bears some resemblance to the texture found on the in game armor.  I have only seen it for sale at Wal-Mart, though I am sure it is available at any place that sells exercise equipment.


What Tools Do I Need?

Alright, so at this point, hopefully you have selected or even purchased your foam and are ready to start with building.  You may realize at this point that you don’t have any tools.  Chewing through foam with your teeth won’t produce the clean lines you will want, so we need to go shopping.

The Most Basic of Basics

Hobby Knife:

As I said before, chewing through the foam isn’t ideal, so you will want to cut it with something different.  I recommend a hobby knife.  They are fairly cheap and the blades are easy to come by.  These will give you clean cuts, which will make your job much easier once you start gluing.  The most popular brand of these is X-ACTO.  They are available at every craft store (Hobby Lobby, Michael’s, etc.) as well as general merchandise stores like Wal-Mart.


Hot Glue Gun: 

This is the most cost friendly solution for gluing foam.  You will use it for hill and valley cuts, as well as connecting pieces of foam.  Low temp is generally preferred as it dries more quickly; however, I use a high temp to reinforce my seams from the back, as it is easier to apply a large amount to a large area.  These are available in all the same places I recommended for the hobby knife.

Glue gun isolated on a white background


For marking lines.  I don’t think a picture is necessary.

Heat gun:

One of the main benefits to using foam is that you can heat it, form a shape, and once it cools it will hold that shape.  You can use a hair dryer, but it makes it a much more tedious process than necessary.  You can get a basic heat gun for $20 or less at Harbor Freight or Wal-Mart.  As the name implies, it gets extremely hot, so please exercise caution and common sense when using one.


The Not-so Basics

At this point you are probably saying to yourself, “wow, working with foam is so cheap!  I am gonna run out and by this stuff right now.”  Do that.  I’ll wait.

I am going to assume that you are back from the shopping trip now.  Congratulations on your new tools. Do you still have money left over?  Do you like making your life easier and your costumes and props better?  If you answered yes to either or both of those questions, this section is for you.  These are some of my recommended tools that aren’t necessary, but you will appreciate owning.

Foamwerks Cutting Tool: 

This thing is awesome.  I love it.  It is a great alternative to a hobby knife.  The handle design gives great control and comfort and also acts as a storage area for additional blades.  The cutter itself is built in a way that will allow you to make perfect 45 degree cuts every time and when used with a straight edge, will give great normal cuts as well.  The downsides are that no one carries them locally, that I have found, and that replacement blades have the same issue.  They have to be ordered online.  I got mine from Amazon.  Edit: One of our readers let us know that Joanns fabrics carries them locally, however they are double the online price.  If you are desperate, sounds like a solid option.


Hot Knife: 

This is similar to a hobby knife, except that it gets extremely hot which assists in giving your cuts a more finished look.  The downside to this is that the replacement blades tend to be pricey.  They are generally available at local hobby stores like Michael’s and Hobby Lobby.


Knife Sharpener:

This will allow you to sharpen your hobby knife blades as well as blades for your Foamwerks cutting tool.  The money you spend upfront on the sharpener will pay off over times with using less blades.  These are available at Wal-Mart and generally any place that sells pocket knives.


Rotary Tool:

A rotary tool is something that anyone that builds anything should own.  Its usefulness and versatility is unparalleled in the tool world.  Specifically for working with foam, they come in handy for sanding down uneven edges as well as other miscellaneous tasks.  They can be found at hardware stores.


Contact Cement: 

Contact cement is a nice alternative to hot glue for joining foam pieces together.  Not everyone likes it, but I personally love it.  How it works is that you brush it on to the two pieces you are joining together, let them sit for a few minutes, and then push them together.  I have found since I started using it that my seams look significantly better due to them not having any thickness like hot glue seems have.  Another benefit is that you can heat the foam to shape it after gluing.  If you do that with hot glue, you stand the chance of having the glue become liquid again and losing its hold.  There are downsides to it, however.  The biggest one is the time it takes for the cement to get tacky after you apply it.  Hot glue is a very short working time, but with cement it’s a much longer wait before attaching pieces.  Another downside is the price and availability.  It tends to be significantly more expensive than hot glue and it isn’t available at nearly as many places.  I have found it locally at Home Depot and you can buy it online.  Many people prefer Barge brand cement, which I have purchased through Amazon.  I am indifferent between brands and haven’t noticed any big differences.


That’s it for Part 1: Be sure to check back for Part 2, where I will cover basic armor building techniques with pepakura!



Filed under How To's

4 responses to “Working with Foam: Part 1

  1. Rachel Dow

    Joann’s has those Foamwerks cutters…for roughly twice as much as online.

    Liked by 1 person

  2. Personally, I’m a huge fan of the Versa-Tool you have pictured above. The knife is very accurate and the heat provides really smooth edges on cuts.

    Liked by 1 person

  3. BeardedDalek

    I use multipurpose scissors from Harbor Freight, which look almost like pruning shears, to cut foam, as well as just about everything else. Like all scissors, the edge is somewhat less smooth than a disposable blade or hobby knife, but you will be sanding it anyway. Also, I rate a heat gun second only to the rotary tool in importance with foam. I find they work far better and on more materials than a hair drier.


    • kcghostbusters

      Holy moley, how did I forget to put a heat gun in that tool list?? I blame my editors. Honestly though, thanks for pointing out that oversight.

      As far as scissors go, I have used scissors, but I definitely prefer hobby knives. The better cut means little to no sanding.


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