Fin Box repair

[TallDude]

Here is a board I recently salvaged from a dumpster. The badly damaged areas I cut out and glued in a piece of EPS with Gorilla Glue. It's natural foaming (as it cures over night) fills all the voids. It sands crispy like you'd expect glue to. I like it. Too many melt down problems with epoxy that gets too thick (mass = heat squared with epoxy).

[createinquiry]

Jumping off talldude's advice bevel the edge.  Foam in those yolo boards is sandwiched between two layers of ply/veneer. Beveling that edge will give you something other than paint, filler, or sticker to adhere to.

[scottg]

Just in case anyone is still watching this post, I have another question about Gorilla Glue.  When I took out the old EPS, I took it down to the top of the board.  All the way down to the fiberglass as you can see in the photos above.  Will the Gorilla Glue adhere to that OK?  If so, I can do my work this afternoon instead of having to order more epoxy and have it delivered.  It would save a lot of time and money.  But I don't want to do it if it won't work as well.  I have fast set epoxy here now, but I have been pretty well scared out of using it on this project after this thread.

[scottg]

Will the Gorilla Glue adhere to the fiberglass that is on the inside top of the board or is epoxy going to be a better solution there?

[createinquiry]

I use the white gorilla glue regularly and it will adhere to the bottom surface of the deck without problem. It will also expand, so don't worry about getting a good fit/finish on that chunk you are gluing in until after it is glued into the board.

One of the small bottles will be more than enough.

[PonoBill]

Gorilla glue sticks to about anything. Don't forget to follow the instructions and spray it with water. Nothing happens until you do. For filling areas like you have I frequently use blue construction board. It's got a higher compressive strength than EPS (about 25 PSI for common lumberyard blue board vs. less than 10 for common EPS) so it's a little stronger when well bonded. Nothing like Divinycell with 200-300 PSI, but readily available, cheap, and sands well.

[scottg]

I just found out about the blue board.  I wish I had known that before I went out to the only place in town to buy incredibly expensive, small pieces of EPS.  BTW, what about the pink XPS?  I do not know if the blue board is XPS, but will the pink board work?  I happen to have a large piece of the 2" stuff.  It seems so much stronger.  Any drawbacks?  I am so glad to hear about the Gorilla Glue.  I will be done tonight!  I still needed a few more pieces of EPS, so if I can use the pink board from Home Depot, then I will have everything I need.  And if I can use that stuff, there is a film that encases the board.  Should that be peeled off?

[Dwight (DW)]

You can use the blue stuff. Whole boards made from it are not considered good though. Risk of off gassing.

I've seen EPS board with foil backing at Lowes. Probably Home Depot too.

[TallDude]

I get my scrap foam from a local Building Materials Supply. They sell stucco finishing products, and have a foam shop where they hotwire architectural exterior trim shapes for me. They have the most common weights of EPS. I can by blocks from them as well. They have a huge strap pile, and they give me all I need for free  I like free.... I have a couple friends who, like me are contractors who shape and build there own boards. We all get our supplies cheap through our construction suppliers.

[scottg]

I like free too, but thanks to the suggestion of getting EPS at Home Depot, I was able to get everything I need within a mile of my house, (minus the small pieces of core-cell, I am going to wrap the new box in.  Got a free scrap place for that kingly stuff TallDude???) and for the most part, pretty cheap.  As you might have gleaned, I am on a tight budget.  The board was $350, and pretty dinged up.  But I might end up on the water for under $500 total.  That was the only way I could do it.  It might be a duck, but it is light, fast, floating and hopefully strong and water tight.  I hope to be back out on the water next week!

[peterwSUPr]

I've been using core-cell for kiteboards, for quite a few years, and more recently paddle blades.  There is a shop in Toronto www.noahsmarine.com who cell smaller pieces of corecell.  I'm not sure how it might work to ship to the US, but shipping in Canada was not bad if buying a few sheets.  If you only need smaller bits they could probably cut a piece into some smaller sizes for shipping.  Looking online there is not a huge supply of off-cuts currently http://www.noahsmarine.com/items.asp?Cc=COREC-SECONDS but the A400, T550 and T600 might be in the target density for our purposes.  The A1200 would be about twice the density of what I'm using, and it probably bulletproof!

Peter

[Dwight (DW)]

Sign shops sometimes have PVC foam board. I saw a video from inside the Bark factory and spotted plywood being used instead of Corecell.