I don’t get it–and I’m confessing that I thought XTR was just Dow blue foam–extruded polystyrene–too dense to take hold of epoxy lams for very long–delam city…but everyone is super-excited about the perf of these blue boards over there.
What’s difference between “XTR” vs. Dow blue XPS?
Anyway I found a guy that will sell me Dow blue sheets in 4" x 2’ x 8’, so I’m wondering if I should be thinking about blue board vs white–I like blue, I like denser foam, less water penetration…
Is XTR just roughed up the way I’ve read people describe , or is it differently lammed/cured/coated/vac’d/pressure-cooked/nuked …
supposed to be a different formula but has the same gassing problem.
Javier has a patented system of sticking super hot needleds into the finished hotcoated board that allows the foam to breathe directly to the surface. Since XPS doesn’t absorb water direct exposure isn’t a problem and the free channel tot he surface supports out gassing. The hot wires seal the resin aloing the micro channel. It’s a very complicated, expensiveand time consuming process that he spent alot of time perfecting… They supposidly have the same flex if not beter than a PU. Just taking an owner’s comments…
If you glass Blue XPS it will breakdown and eventually delam and nothing really like to stick to it anyway although Drew’s making them down in Florida.
I current have two boards with 2" blue down rail bands instead of solid balsa surrounding a EPS core so we’ll see how they hold up compare to the two with 1.75" of corecel for railbands instead of wood. bending foam is easier than bending wood.
the evironmental laws in europe are different and here they use co2 as blowing agent. would this elimenate the bubble issue?
i just went through alot of epoxy glossing posts and was wondering if those xtr delam issues have been caused by the same mistakes as glossing, dirty hands and so poisening the epoxy?
Has anybody pre-heated, or pre-hot needle penetrated an XPS blank. I’m making the assumption that the XPS outgasses when it gets warm. Maybe there’s a way to accellerate the exhausting of the blank before it’s glassed or shaped.
I don’t know…poke some small holes, put it in a hot box for a few hours?
I’ve tried the Dow blue sheets, I wouldn’t waste my time or cash on them again, they have always delammed and it doesn’t get very hot here.
There was a thread on here a while back though and someone was using the blue foam from dock billets which is the least dense type of blue foam they make. they were pretty stoked with the results if I remember correctly. I’ll try to look it up.
I have a friend who have made quite a few boards from blue dow foam, no delams yet. It’s kind of hard to shape though, but has a nice surface when done. No need for any inserts for any boxes, the foam is rock hard. What I don’t like is the way it bends just a little bit then snaps violently.
From what I understand the bonding issues are related to some kind of nonstick additive(teflon, silicone?) so the foam doesn’t stick to the form when they make it(it’s extruded after all). The foam will contain a small amount of this which creates problems with epoxy bonding. if the XTR is blown without this additive because of a different production process/machinery, less problems. However, there is still the problem with blowing agent being caught inside the closed cells, since this is a blowing agent it has the potential to expand alot more than air when it get’s hot, thus the potential for outgassing is huge.
What I don’t get is how small holes in the lam is going to help unless the entire lam is punctuated. How close are the pinholes they make? This is closed cell foam after all, so how does the gas get from one cell to the other to the holes?!?!?!
What I don’t get is how small holes in the lam is going to help unless the entire lam is punctuated. How close are the pinholes they make? This is closed cell foam after all, so how does the gas get from one cell to the other to the holes?!?!?!
The holes are 2" apart. I love my XTRs, they have more response than a PU/PE, a little bit stiffer but more drive. Feels more “lively” than an EPS too.
Hi Surfstar 101! Thanks for the pics. Very interesting to see, I’ve never seen photos of those vent holes before. Where are they placed on the board? The ones in the photo look like they’re on the bottom of the board?
Could You please post some more pics of where the vent holes are placed on top and bottom?
I’ve made one blue dow foam board and it delamed in the bottom of all places. But I think it was because the i had it in the sun on a warm summer day.
Before that the board was fine for a year and a half.