| All the engineers I've talked to, even at ITW Foamseal, say, that the 2 pounds per cubic foot stuff is "designed" only for Noise Harshness and Vibration. I had a long conversation with Art Goldman at ITW, and he was very insightful. But he said, it's possible on cars that are already fairly stiff, it "may" help, and the 2pcf foam may not get challenged to the point of breaking it's bonds or cracking. I'm not ready to try that on my floppy convertible just yet--the 2pcf ITW foamseal, I mean. I am still afraid the amount of flexing will challenge the foam too much. So, higher density foam would be the answer. ITW even tried it in the aerosol cans.... The main reason no one puts higher density stuff into aerosol cans is it can mess up the density of the heavier foams. The OEM machines that apply this stuff to cars, use pumps, not gasses, to push the two liquids together. And everyone thinks there's no after-market for it. (speak up if they're wrong, here--let them know!!) That said, all the engineers I spoke with: all of them-- said that the minimum pounds per cubic foot foam they would trust for structural enhancement was about 8pcf. It has a tensile and compressive strength 5-10 times higher than the ITW foamseal. The difference between say 45 psi and 250-450 psi read SAE article 2001-01-1609 and 1999-01-1785
Art mentioned a project where an OEM convertible could not even be made without a B pillar piece being injected with 25 pcf foam!! I asked him, since the canisters won't work, how Joe Blow DIY guy would apply heavier density foam: 1] buy two 55 gallon drums (!), one resin; the other: catalyst.
2] mix smaller amounts up in a container with some mechanical mixer, like a drill/paint mixer.
3] as soon as humanly possible, get it into the frame rails, via some holes and funnels. The heavier stuff expands slower. How this actually gets done, is another matter. Not impossible, just not as easy as squirting it in with a nice injector system. Mike Kojima still insists, as do many of you, that your cars are stiffer as a result of putting the ITW foamseal in your cars, and I'm believing it. Remember his article states that foamseal will make a rail 40% stiffer, but he mentions also that there's foams that can increase the strength to 300%. I also believe, after researching this, that greater structural benefits, and potential for much greater durability exist in sticking with the SAE articles' and OEM's choice of higher density stuff, especially for a car as floppy as a convertible. Now, I just gotta figure out how to get those 55 gallon drums ;-) _MWS
Crash Test Dummy(tm)
"taking it on the chin so you don't have to..." |
