My friend tried to repair his EPS epoxy longboard (Global) yesterday. He had buckled the deck surfing a hollow beach break. I’m surprised the board didn’t snap in half like the other 2 guys who tried to longboard that spot.
Anyway, after removing a 2in strip of sandwich material across the deck from about mid rail to mid rail and some crumbled-pinched foam (leaving a 1/2in deep V). He attempted to tape of the rails and fill the entire thing with RR2000 epoxy and Q cell mix. (I think Q cell, a filler of some sort anyway) After curing he discovered the epoxy had melted through the underlying foam!! If you poked your finger through the crust you can see bottom of the board.
I told him the large amount of resin created to much heat, but I’m no expert. I was wondering what the real swaysperts think. Greg L. should be up by now. Seriously though, I would appreciate any help. I’m going to start shaping eps/epoxy and know there will be repairs in my future.
Of course the best repair is to jam more foam in, shape it smooth, then glass it. However I have repaired larger holes in many boards with a filler/resin mix. If that is his preferred method of repair, he needs to go at it in layers, not all at once. Also, the mix should not be pourable, but packable (with gloves on), if it flows at all it will be a huge pain to sand or shape to the previous form. Learn now that almost all “shortcuts” end up taking longer in the end.
Certain Chinese blanks will react with some epoxies, I’ve seen them melt just like PE hit it. Q-cell, cabosil or other fillers will also cause epoxy to exotherm really hot, so it could have melted. The best way to do repairs like this is with pour foam since there is no heating, and it’s PU so there’s no reaction with any type of foam. What was formerly a buckle will likely be two pieces now after the melted foam is removed.
Thanks Pete
Looking forward to the planner mods. But that’s another thread. I’m a bit confused on the PU pour foam. I’ve never heard of it and I thought you could only use epoxy with EPS? Could you explain a little more?
It’s polyurethane 2-part foam (2lb density). You mix equal parts and have about 40 seconds before it goes off. While it’s still in the liquid state it will run into the nooks and crannies of a repair. It also bonds to everything. Eva uses it a lot, you can see it used on repairs at her site www.boardlady.com. You can get it from AeroMarine.com.
You can still repair that board. Saw out the piece width-wise where the melted foam was. Splice in a new section using polyfoam and Gorilla Glue, shape the foam, and glass it like you would a snapped board. There’s lots of info in the archives on ways to align the two pieces. Bond the foam splice to one side first and get it to the approximate contours before bonding the two halves together. Gorilla Glue must be clamped, so use a long bar clamp with foam or wood adapters for the nose and tail. I only use poly when replacing eps foam, just my preference but it is a lot easier to work with.
Seriously though, I would appreciate any help. I’m going to start shaping eps/epoxy and know there will be repairs in my future.