Snapped my Stewart CMP epoxy. Was super light, and I had it out on a thumping beach break day. Pretty clean snap, and the pieces mate together very well. However, I normally work with poly and not epoxy. Any suggestions on what would be a good adhesive to glue it back together. I am unsure of whether gorilla glue would be good, considering it is going to expand and possibly tweak the rocker.
I mix a brew with epoxy resin and Q-cell. Can make it quite thick so the slow setting epoxy is less likely to escape through gaps in the tape. A runnier batch afterwards will get into and remaining gaps. Be careful if the volumes of the spaces are too large as the resin will get hot and can destroy surrounding foam.
There are probably a lot of answers to that question - I would use epoxy resin, paint both sides, clamp them together. I think it was SDRepairman who used pour foam as an adhesive, he said it is very strong, if you tried to re-break it it will break somewhere else.
One thing I would make sure of 'tho, regardless of what glue you use, is that everything is clamped into place so nothing can move once the two halves are glued together with the correct rocker. I think sharkcountry had a pic posted awhile back of his broken board clamping system, you might try the search function and see if you can find it.
If you repair it, it will definitely not be light anymore; more like poly board weight. You probably won’t like the stiffer feel either. Use clear gorilla glue or pour foam and clamp it per the info in the archives about repairing broken boards. The glassing minimum length would be the width of the board centered on the break, 2 layers each side. You can see the repair steps here: http://www.boardlady.com/snap.htm but bagging it isn’t necessary. Lengthwise clamping is mandatory when using a foaming glue, and use perimeter clamping to maintain alignment and rocker (archives).
I’ve never used any expanding type glue or resin so can’t comment on them. When using regular resins I find you can get enough tension with the brown packing tape along the rails to not require any special clamps. Of course a flat or curved surface is needed to put the taped board onto and spend plenty of time to get all your curves alligned. Always a good idea to try and get a view from a distance away to get a true sense of whats going on.
Using epoxy to bond the two halves together is a recipe for disaster. EPS breaks are a huge bonding surface with lots of nooks and crannies to fill, so with epoxy there will be melted foam and the bond (which you will base all further work on) will be crap. On poly boards, it’s a different story and a thick resin filler works best since you’re not concerned with melting foam.
I’ve seen so many cases of melted EPS in fin boxes, leash plugs, etc. on production boards that it is ridiculous. The reason for this is that they’re using the same router templates for installing these embeds as poly blanks which allows for too much resin. If you can’t see the melted foam, well nobody knows. However, a big pull on a leash plug or a fin hitting a rock will show the story. Take a 1" hole saw and bore some holes in a piece of EPS scrap at various depths then fill with epoxy/filler and you’ll see what I mean. While I’m on this rant, for dedicated EPS use the best way to supply finboxes, SUP handles, leash plugs, etc. is to have them pre-set in HD foam so that you only need a simple rectangle or round template to route and can use a foaming glue or minimal epoxy filler to set. It’s a faster and easier install as well.