Just a little warning for those making home depot foam boards

I just cut some of the deck skin off my home depot foam/epoxy board to see if I could maybe just throw a new deck on it, to cure my catastrophic delam issue. I was really suprised to see that the glass hadn’t delamed off the foam at all. In fact, the only place where I had a bonding/delam issue was where the two sheets of foam were glued up with elmer’s glue-all.

I’m 99.95% sure that I wouldn’t have ran into any any problems had I laid up my sheets of foam board with epoxy instead of elmer’s.

Just something to think about.

I suspect that can be a problem, but out of 4 kiteboards I made in ‘01, two are still being used, one I own, the the last one broke in half on a big landing…well over 20’, prolly waaay bigger than that.

Used Elmers to glue up 3 layers of 1/2" styro, then discovered non set tacky glue.

Haven’t made another yet.

Seems the weak styro is weaker than Elmers.

Did you let the board set a day after shaping?I shaped a H.D. board two weeks ago. Where I shaped into the glue line the glue was still tacky. So I let It dry before glassing.No problem with delams. Gordon

I forgot… I actually let the Elmers sit around for about a month and a half, before starting to shape. Was inventory season, so everything sat in the back warehouse.

Quote:

Did you let the board set a day after shaping?I shaped a H.D. board two weeks ago. Where I shaped into the glue line the glue was still tacky. So I let It dry before glassing.No problem with delams. Gordon

I let my blank sit a week before cutting my outline, and the glue was still tacky when I cut it out. That should have been my first hint. Elmer’s only dries where the air can reach it. If you have a board outline, drying from the outside edge to the inside, it is pretty much sealed on the inside once the outside edge dries. I know eps breathes a little, but a month of drying would probably be safest.

Oct/Nov timeframe we had a discussion about Elmers glue drying. One suggestion that came out of that was to let the glue tack-up on both sheets for about 5-10 minutes before sticking the sheets together. This is what I did on my glue up blank, but then life got busy and I have not cut the template so no it has dried for more that 6wks. Hopefully it will be a good bond. In the future, as per Bert’s suggestion in the vacuum/sandwich construction thread http://www.swaylocks.com/forum/gforum.cgi?post=183391, I’ll use epoxy and ultra light weight glass. His experience was adding the glass actually reduced the weight. If you have not read his thread it is worth while even if you are not going to vacuum bag.

Adding microballoons to the resin between layers will also help your bond. I was reading about the Elmer’s trick and I thought there would be issues with the glue not drying right. Epoxy will solve that. Thermoset resins(glues) do not need air to dry. You know, nearly all of you live in close proximity to the places that make the foam for Home Depot and you can get it in the right sizing so the glue up is unnecessary. It’s also cheaper to get it direct and I’ve never run into a minimum order size from any of the companies I’ve bought from. I know HD seems convenient but come on guys, look in the phone book under insulation. You’ll probably find a place.