Making Polyurethane Foam at Home: Hard and Flexible Varieties
Two-part urethane mixtures let you create either rigid or soft polyurethane foam. Rigid foam serves purposes like insulation, temporary flooring, theatrical props, and components in coolers and aircraft. Flexible foam is common in packaging, cushions, and mattresses. Safety gear such as eye protection and a respirator is necessary because the chemicals are somewhat toxic.
By Parker Campbell9 steps
Baby car seats often use urethane foam as padding.
Polyurethane foam is available in rigid and flexible types. The rigid version is used for applications including temporary stages and flooring, wall insulation, theater props, coolers, and boats and airplanes. The flexible version is found in packaging, padding, seat cushions, and bedding. Either type can be produced from two-part foam mixtures. Because these materials are semi-toxic, eye protection and a respirator mask should be worn to safeguard your eyes and lungs while handling them.
Step 1
Select a mold appropriate for the foam you intend to produce. Rigid foams are generally employed for items like wall insulation, theater props, and boat siding. Whatever object you wish to create with the foam, use a mold shaped for it.
Step 2
Apply mold-release spray to the mold. Let the spray dry for 24 hours prior to introducing the foam liquid.
Step 3
In a large, disposable container, combine the two foam components in an equal 50-50 proportion. Use a stirring stick to blend the two mixtures.
Step 4
Within 15 minutes of mixing, pour the liquid into the mold. The foam begins to set within that same 15-minute window.
Step 5
Leave the foam to cure overnight. To allow proper curing, keep the mold in a room at approximately 70 degrees Fahrenheit. Curing will not occur properly at colder temperatures. After 24 hours, remove the foam from the mold.
Step 1
Prepare the mold for the foam by completing steps one and two as described above.
Step 2
Combine the two parts of the urethane foam mixture at a ratio of 28 parts hardener to 72 parts urethane foam liquid. Blend the two parts until they begin to expand.
Step 3
Pour the foam into the mold, leaving a small amount of space for expansion. Full expansion should occur within 15 minutes.
Step 4
Let the foam cure for 24 hours at a temperature of at least 70 degrees Fahrenheit.
