FlexFoam-iT 4 Five Gallon Kit 72Lb (799796)
FlexFoam-iT! 4 Tuff Stuff is self-skinning and has relatively high tear strength for low density foam. It is also stiffer and slightly harder to compress vs. other FlexFoam-iT! products. FlexFoam-iT! 4 Tuff Stuff was developed for fabricators that make foam props for the Halloween industry. These props are on display and within reach of the public. They have to be lightweight and able to take abuse from general public handling. Components must be weighed using a gram scale in order to successfully use this product. FlexFoam-iT! 4 Tuff Stuff is faster than other foams - at room temperature, you have about 25 seconds to mix and pour. This foam starts to rise almost as soon as you start mixing Parts A & B. Mixture expands about 10 times its original volume depending on mass and mold configuration. Tack free time is about 20 minutes.
HELPFUL TIPS FOR CASTING FLEXFOAM-iT URETHANE EXPANDING FOAMS:
Thorough pre-mixing of both Part"A" and Part"B" in their original containers prior to measuring out.
Specifically, failure to pre-mix Part"B" prior to dispensing will cause the ingredients in the system to remain unbalanced. Storing and working with materials in cold environments will cause the components of Parts "A" and "B" to separate (i.e. vinegar and oil). If these components are not brought back to proper room temperature and reconstituted this will cause failure in their cross-linking when mixed together.
Thorough mixing of Part"A" and Part"B" combined.
Once combined together, Part"A" and Part"B" must be evenly and thoroughly blended scraping both sides and bottom of the mixing container. A double-mix pour technique, time allowing depending on product blended pot-life, will assist in the most successful mixing technique. Often with the foams, users will work quickly as materials generally have a short pot-life before expansion occurs and neglect a thorough mixing procedure.
Use of silicone-based release agents in molds where foams are cast, will cause collapse of the foam cell structure.
Mold configuration; if the mold is 'closed' and not capable of allowing gas to escape during the expansion & cure process of the foam, the de-molding procedure will result in the gases escaping from the cured foam causing collapse of the casting. Using a mold where the gases are allowed to escape during cure is important.
If the casting comes out of the mold collapsed; often it can be compressed which will cause it to re-inflate.
Cold molds can also contribute to foam collapse; sometimes materials will be kept at proper temperature, however, if the material is poured into a cold mold, that may cause cure-issues and collapse of the foam casting.
HOW TO IMPROVE THE SURFACE FINISH OF FOAM CASTINGS USING BACK PRESSURE