Hot Wire Foam Factory All Purpose Foam Coat

Article number: 31910253
Availability: In stock (5)

All Purpose Foam Coat

Rock hard concrete-like coating that protects and beautifies your foam projects!

Easy to use - simply mix with water. It's tough yet still sandable. It is inherently fire resistant. Can be used outdoors when sealed with any outdoor paint, or mixed with Boost liquid fortifier, or Bounce liquid rubberizer. Apply thick with a trowel or thin with a paintbrush. Sets up in only about 15 minutes. Extend the drying time by adding up to 50% latex paint with your water before mixing into the dry foam coat.

Dollar-for-dollar, our Foam Coat covers 4x as much as Rosco Foam Coat, is at least as strong, and has a longer shelf life.


  • Paintable
  • Sandable
  • Fire-resistant
  • Adheres to polystyrene foams
  • Applied with paintbrush or trowel
  • Many decorative surface textures can be created
  • Soap and water clean-up
  • Compatible with our Boost liquid Fortifier and Bounce rubberizer
  • Made in USA


Used For:

  • Coating Styrofoam, white beaded EPS, and extruded XPS foam
  • Adding strength and a fire-resistant surface
  • Theatrical and studio props and backdrops
  • Holiday props, like Halloween tombstones and yard props
  • Art and craft projects



Thickness: 1/64" 1/16" 1/4"
3lbs: 36 sq ft 9 sq ft 2.25 sq ft
25lbs: 288 sq ft 72 sq ft 18 sq ft

MIXING: Settling may occur in shipping causing a gritty texture that does not stick well. Remix if there is separation in dry mixture. Remove or break up any clumps. Use when temperatures are between 40°F (4°C) and 100°F (38°C). Mix in a clean container with clean water. Use 1 part cool water per 3 parts of powder (for example, 1 cup of water per 3 cups of powder). Add water to powder and mix until Foam Coat turns to a smooth paste. Add more powder or water as needed for your application. A drier mix is stronger. If you add Boost or Bounce, a wet mix is stronger. Do not over mix, or separation can occur. You can add powdered or water based cement pigments while mixing in the wet ingredients.

APPLYING: Fill big cracks and holes by applying pasty mixture with a trowel. If using extruded foam (ie Blueboard or Pinkboard) roughen surface with coarse sandpaper. Apply with a paint brush, stucco brush, trowel or hopper gun. Use thinned mixture to texture large areas. For best strength apply at least 1/4” (6mm) thick. Multiple coats may be applied. Brushing or spraying a thin first coat, called a scratch coat, will make the next coat much easier to apply. Try texturing surface as the coating sets.

CURE TIME: Working time of 10-20 minutes. Reaches full strength in 12-24 hours, depending on temperature and humidity. Add up to 50% latex paint to the water to extend drying time to 40-50 minutes.

FINISHING: Remove dust before painting. This product goes on smooth and can be sanded. Can be used outdoors if sealed with paint. Add Grit texturizer to create a rock-like surface effect.

CLEAN-UP: Clean tools and brushes with clean soapy water before coating hardens. If you add Boost, don’t leave any residue as it will be impossible to clean after it dries.



Additional Info:

WARRANTY: HWFF Inc./dba Hot Wire Foam Factory warrants this product to be of merchantable quality when used or applied in accordance with the instructions herein. The product is not warranted as suitable for any purpose or use other than the general purpose for which it is intended. Liability under this warranty is limited to the replacement of its product (as purchased) found to be defective, or at the shipping companies’ option, to refund the purchase price. In the event of a claim under this warranty, notice must be given to The Hot Wire Foam Factory in writing. This limited warranty is issued and accepted in lieu of all other express warranties and expressly excludes liability for consequential damages. MSDS available.


⚠️ California Proposition 65 Warning: This product contains crystalline silica, a chemical known to the State of California to cause cancer, birth defects, and reproductive harm. While mixing the dry ingredients use a dust mask or respirator with an RPE of 20 or 40. For more information, go to or HWFF's information page: California Proposition 65.


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