The All Time Best Way To Make a Urethane Foam Sculpture

November 5, 2018

I previously posted an interview (https://www.aeromarineproducts.com/frank-holder-artist-sculptor-of-foam/ ) with Mr Frank Holder of Greensboro, North Carolina about his innovative urethane foam sculpture technique, bending partially cured foam and shaping it to form beautiful organically shaped sculptures. After lots of Q&A about his process (he’s a very patient man, thanks Frank), I produced a Frank Holder-like foam sculpture. It was incredibly fun! While I won’t be giving Mr Holder any competition with my attempts, I will absolutely be making more of these. You should try this technique. This how-to post will help you discover a new and interesting artistic expression!

Materials needed:

• AeroMarine Products #2 Density Urethane Expanding Foam
• Plastic containers and plastice utensils for measuring and mixing the foam
• Plastic painter’s drop cloth
• Large foam board (I used foam insulation panels)
• A few pins or thumbtacks.
• A block of wood to use as the base
• A nail that will extend through the wood base and stick out an inch or two
• AeroMarine Products 300/21 Epoxy Resin
• Epoxy Colorant
• AeroMarine Products fumed silica
• Gloves
• Dust mask
• Small ship brush
• A bread knife
• sandpaper (I like 60 grit)

Optional Stuff:

• A dremel or other power sanding tool
• AeroMarine Products 400/21 Epoxy Resin. The 300/21 works fine.  However, the 400/21 is just a little more viscous and goes on thicker for the final seal coat.
• AeroMarine Products 5 Minute Epoxy Resin. You can use either this fast setting epoxy adhesive or the 300/21 epoxy to fix the foam to the base or another type of glue.
• Urethane Colorant. If you want just one uniform color to your sculpture.

Your work area:

• Clean, level work surface, covered in paper or plastic for easier clean-up. Because of the size of this project, I had a clean, plastic covered space on the floor for the first part and my usual plastic covered work bench for the second part.
• All materials comfortably within reach.

Project steps:

• First, I swept the floor where I was going to be working and laid down a plastic drop cloth. Then I set my foam insulation board on the plastic. Next, I pinned another plastic drop cloth to the foam board, covering the entire board but leaving all the excess plastic to one side. That is because I need to fold the plastic over the board once I pour the #2 foam.

• Next I measured out about 12 ounces of each side (Part A and Part B) of the urethane pour foam. If you are using urethane colorant, mix it into Part B. I went with yellow because it seemed like a nice base color. Mix Part A and Part B together, stirring vigorously for about 30 seconds.

• Once mixed, pour the foam mixture onto the plastic and foam board set up. Pour in a straight, even line. You can tilt the board to even out the pour. It should look like a long surf board.

• Give the foam a minute or so to rise and expand. Once it stops expanding, start poking it with a gloved finger. You want it to not come away on your glove, but stick to it a little bit. Once it reaches that point, fold the other half of the plastic over the top of the foam.
• You want to slowly and gently bend the foam, starting at one end. If you go too fast, the foam will snap, so slowly and carefully bend the foam into your desired shape.
• Once you have the foam maneuvered into the shape you want, hold it there. You’ll need to hold it for 5-10 minutes. Timing is everything! If you let go too soon, the foam will try to spring back into its original flat shape. The foam gets warm as it cures. When you can tell that it’s starting to cool off, you can start relaxing your grip and test to see if the foam will stay put.

• Once you let go, let the foam harden up for another 20 minutes or so.
• Next, we need to mount the foam onto the wooden base. First, hammer your extra long nail through the center of your block of wood. It should stick up from the wood an inch or two.
• I held my foam several different ways to figure out how I wanted it mounted to the base. Once I knew, I just pushed the foam onto the nail.

• Before I permanently mounted the foam to the base, I wanted to carve out certain areas of the foam. I used a bread knife with great success. I carved away at it slowly, frequently putting ithe cured foam back on the base and standing back to look at the shape. Where I wanted a hole in the foam, I slowly twisted the bread knife into it and then carefully expanded the hole to the size I wanted. The actual cutting and sculpting of the foam took me several days. It’s good messy fun, so be sure to wear a dust mask or respirator. I would work on it for an hour or so and then come back and look at it for every angle before starting to carve again. Mr Holder plans out the shapes he wants in advance. Since this was the first time that I tried this, I had no idea where I wanted to go with the sculpture. Thus, I went slowly and looked at it often. Once I was happy with its shape, it was time to affix the urethane foam sculpture to the base.

• To permanently mount the sculpture to the wood, I used AeroMarine Products 5 Minute Epoxy dribbled into the hole the nail made in the foam.  AeroMarine Products 300/21 Epoxy Resin would work as well. Once the epoxy is set, you can start apply epoxy to the exterior of the foam sculpture.

• If you colored the foam, you could go with a simple clear coat or two of AeroMarine Products 400/21 Epoxy Resin and be done. The 400 Resin is thicker than the 300, so it sticks better to vertical and sloping surfaces. I like to do things the hard way, so I decided to do several coats of differently colored, thickened AeroMarine Products 300/21 Epoxy. My tactic was to apply a coat of one color, let it cure, apply the next coat a different color and sand it down so the the layer underneath showed through in different areas.
• To make the epoxy for coating the sculpture, I measured out about 8 ounces of the 300 Resin and mixed in a tablespoonish amount of epoxy colorant. Then, I mixed in about 6 ounces of fumed silica to thicken the resin. Next, I measured out about 4 ounces of 21 Hardener and then mixed it into my colored, thickened resin. *The reason we mix everything into the 300 resin side first is because it can take some time to get all the additives smoothly blended together.  If we add the hardener and resin together first, we start the clock on the pot life, which is about 20-30 minutes with our epoxy resin.*

• Once it was all mixed up, I used an inexpensive chip brush to apply the epoxy to the foam sculpture. I let it cure for 24 hours and then applied the next coat of differently colored and thickened epoxy. After the second coat, I sanded, both by hand and with a dremel with a sanding disc. I did this for 5 coats, sanding in between to let the coats underneath come through. Make sure you are wearing your mask/respirator for any sanding because it gets very dusty. After 5 colors, I called it good even though I probably could have gone on for a few more. Time constraints and many other projects pretty much dictated that it was time to wrap it up.
• I applied two final clear coats of AeroMarine Products 400/21 Epoxy Resin to seal it all up, letting the first coat cure for 24 hours before applying the second.

• I think it turned out pretty nice for a first try! Next time, I would do more color coats and thicken the epoxy a bit less so it would be easier to sand down to the next layer.  I would plan out my colors and the order in which I apply them as well. I would also have someone help me with the bending of the foam, so I could get a more elongated shape. Next time!

So that’s how you can make Frank Holder style foam sculpture! Check out his website http://www.frankholderart.com/ and his Instagram, @frankholderart, to see how much better he does it. Try it for yourself! It’s incredible fun, not too difficult for a beginner to do and you can always give us a call if you have any questions, toll-free (877) 342-8860 or email us at info@aeromarineproducts.com. Good luck with all your projects!

« Return