Urethane foam - any differences in

[Rob Patrick]

Last year I broke down and bought a real foam gun - the type that uses the replacable cans of foam. Man what a difference it makes over those crappy cans they sell at HD and Lowes.

I need to buy some more foam for a project and have noticed a wide price range - for example, at fastenmsc.com a 32 oz can of Enerfoam is $18 but a 29 oz can of TriggerFoam is only $9. I've also noticed that HD now sells Hilti foam, but I can't recall the price per oz.

My question - is there any reason to go with a particular brand of foam? My gut reaction is that urethane foam is urethane foam (like a chemist friend likes to say, "it's just molecules") and since the connectors that attach the can to the gun all look to be the same, it doesn't make sense to buy expensive foam. But then again, I don't know what the long term effects are - does cheap foam break down over time or something?

What are your thoughts? Any reason not to go for the low-cost foam?

Thanks Rob

NOTE to reply directly to my e-mail, take off the underscore and everything after it.

[Joe Bobst]

Let's say it again: the better stuff costs more money. There are many possible urethane foam formulations all of which vary wildly in their performance and properties.

Of course it does. Heat and moisture will cause some formulations to revert partially to their unreacted state, i.e., they turn to goop. Others will oxidize, turn to brittle chunks or powdery crumbles. The idea that there is only one kind of foam is way wrong, so if your project needs long term survival don't waste your time on marginal projects. HTH

Joe

[Rex B]

|Last year I broke down and bought a real foam gun - the type that uses |the replacable cans of foam. Man what a difference it makes over those |crappy cans they sell at HD and Lowes.

I've been thinking along those lines, did not know there was a step between the cans and a high-dollar pro outfit. What is it that you bought?

I would like to insulate the fiberglass spa recessed in my deck. I can access it from below. Would this thing be suitable fro spraying a large surface area, or is it a caulking thing? Rex in Fort Worth

[m Ransley]

I have heard they sell foam in maybe 20 lb containers at HD but am not sure of size or quality

[Oscar_Lives]

Many different types of polyurethane foam.

TDI MDI polyether prepolymer rigid semi-rigid flexible high resiliant water blown solvent blown CFC blown