I finally picked up a blank at home depot. It was 2"x2’x8’ and less than $10. I am pretty sure it is EPS; it wasn’t crunchy like the pink, thick-skinned stuff. I checked out there website (http://www.polarcentral.com/) and found some specs on their “R10” foam, but couldn’t find any reference to R10 on my new blank. Has anyone had any luck with this foam or know what density it is? it lists R-values of 8.7 and 7.7 at 25 and 50 degrees on the packaging. I suppose I’ll end up weighing it once I find a scale, but any experience would be appreciated.
Thanks Benny,
That thread was one of the threads that got me hooked on swaylocks when I first started lurking around here. I was hoping for some specifics on my particular foam since I am guessing each Home Depot has different stocks running through all the time. Are you thinking it is 2lb EPS and no vent required?
I love Home Depot!
The insulation sheets of EPS is about 1# density.
The manufacturer I am getting it from and most of the ones I have seen on the net make 1.5 - 2# densities for ‘geological’ uses. i.e. they usually use them as ‘fill’ in construction.
I discovered the local company (mtl canada) after seeing an overpass being built near my home town. They were building the ramps for it out of big blocks of EPS, later covered over with tarping and some other surface before the dirt and ashphalt came along.
Everything I’ve ever seen stocked at Home Depot is 1#. Johan, that even includes in Montreal when I visited my sister! Same stuff as at home…except buying all the crap I needed to rewire her house but labeled in French was a bit of a challenge. 
Some HD’s let you order other densities, some pretend they don’t know what you’re talking about. You might have to visit a few different ones.
I don’t use Elmer’s or any other white glue any more, just foaming polyurethane glue like Gorilla or a cheaper alternative.
That thread brought back some fun memories…I can’t believe it was only a year & a half ago.
“some pretend they don’t know what you’re talking about.”
Hi Ben -
I don’t know if they’re pretending or if they’re just idiots. I took a
2’ X 4’ panel of the stuff off the rack and showed it to the guy at the special order desk. I asked if they would please call the place clearly labeled on the plastic cover sheet (Insulfoam - Chino or Dixon, where ever they got it) and check it out.
“Yes, I think you can special order it.” “Yes, they make it in 2 lb density… see the ‘TYPE IX 2#’ on the outside plastic?”
It took awhile but they came around.
The best language courses are the real-life crash courses. 
And I still don’t know all the ‘technical’ names in french for carpentry/electrical/renovation and I am half french! The plus side is that most of them know the english ones…most of them. Nothing like those conversations that go: ‘You know the thing that does such and such and goes…’
I was able to get a ‘floatation’ billet from the HD in Montreal. I think it was 1.5# , but it has blue ‘veins’ between all the beads … water proof or algae proofing?
Sounds like the HD in the US are better. I had to go direct to the manufacture to get the 2# ‘virgin’ white. Probably cheaper though.
Peace
On the polar guard website they have some fairly detailed specs on their R-10 foam. I noticed the compressive unit was listed in PSI. It would be pretty cool to dial in your vacuum pressure to match the compressive resistance exactly. Make your blank 10% (or 5%) too big, and PU glue your pre-formed outer shell. The max temp for curing is also listed. I’ll have to check and make sure the density matches by weighing the blank that I have.
Sorry, the specs didn’t paste very well, when i tried to paste them in. Still kinda interesting if you can find them through the frames at this site: http://www.polarcentral.com/polar.htm