PF40 Low Density Polyurethane Foam

It's completely rigid. If it is 'hit' it will dent and stay dented. The way to think of this type of foam that helps people the most is that it's similar to (albeit higher density and therefore stronger) Oasis - the type of foam used for dried flower arranging. Therefore, although it would absorb impact from a shock, it would deform and stay deformed.

Our Pattern Coat Primer product is excellent for sealing foam and lower density modelboards. On lower density foams you might also choose to use a scrim of glass cloth to add some more strength to your pattern first. When using the Pattern Coat Primer, a typical thickness would be around 0.5mm.

No, it's expanded polystyrene foam (like styrofoam/blue foam) that you can cut with a hot-wire cutter. To cut PU foam you will need a blade of some description.

Polyurethane is a highly chemically inert material meaning that the vast majority of solvents and household chemicals will not dissolve the PU foam at all.

We are not aware of any easily available solvents or relatively safe to use chemicals that will dissolve the PU foam. If you did need a foam that is more readily dissolved then expanded polystyrene (EPS) such as Styrofoam might make a better choice.

Although perfectly possible to cut the Low Density Foam by water jet, it is more common to use other more simple manual methods. But for more precise applications, the foam works well with all CNC cutting and routing operations where the foam can be easily machined to a shape or pattern

No, this foam is not rated for fire protection.

The PUF40 foam is closed cell so won’t soak up liquids however the open surfaces are quite textured and so would normally be coated with a product like our Pattern Coat Primer/High-Gloss or even an Epoxy Laminating or Coating resin to give a much smoother finish much like in our ‘How to Make an Accurate Composite Pattern by Hand’ tutorial.

Generally this is a closed cell foam and therefore water uptake would be extremely minimal, especially over modest periods of time. However, it should be pointed out that the foam is not not intended for use directly exposed to and permanently submerged in water.

This foam will have thermal insulating properties due to the very high air content (like most foams), however a dedicated insulation foam, such as some expanded polystyrene based foams, would work much better in terms of insulation efficiency