I have a stripped polyurethane board that was pretty rotten, mostly around the fins and tail. I was able to remove the worst of it, but I’m wondering how to fill the voids left over. What’s a good foam filler for the voids, Especially the voids where the fin boxes would go. There are a lot of options I keep finding and I’m not sure which to trust most. I’ve been looking at Qcell, microballoons, and Totalboat Silica Thickener. I’m also considering cutting and fitting polyurathane foam itself and gluing them into the holes. also I’ve seen a lot of guys coat blanks in drywall spackle and things like that, what are the benefits of that and what makes it “necessary”.
Also I have some polyurathane pourfoam left over from a boat I just built, Could I use this to secure the fin box voids?
Pour foam is an excellent bonding / filling agent for pulled-out fin boxes, but you have to secure them in position first as it exerts a lot of force when expanding. I shim the boxes with thin strips of polyfoam until right, put in pour foam then clamp deck to bottom using wood strips. May be better to do that post-glass. For the big chunks missing, saw out and replace with new foam and bond in with pour foam (secure these pieces also). Using resin will leave a rigid glue line which won’t shape easily as the pour foam joint. It isn’t good for filling big voids which will be glassed over since there’s a lot of holes from the out-gassing which have to be filled. Pour foam is very temp sensistive, so don’t use below 70F.
I think I agree with McDing: lovely fence material.
My real original trade is boat carpenter, it’s what I apprenticed at. And you get some boats that are beyond economical repair, not of enough historic or sentimental value to fix at any reasonable cost, as any boatbuilder runs across, I’d imagine you have too. And it’s hard to tell the owner it’s just not worth it.
Considering the constraints you’re operating under, old shape as changed after you took the old glass off and the ruined foam that went with it, probably a lot of questionable foam left that you’d want to get rid of, the list goes on.
For the amount of work involved, I suspect you would be way ahead just going with a new blank. Between glass and resin and lots and lots of fillers, your expense would be lower with a new blank. And then there’s the joys of whatever very limited shape you are stuck with doing with what’s left of this chunk of foam…
Reshapes almost never turn out well. This one, probably worse than most.
I’m making fun, but I just repaired a brand new Channel Island that had a side fin box broken out of it with a chunk gone the size of the void on the right side of your board. I should have stopped to take a before pic, but only have pics of the finished repair… I will post them up later. He got the board for free because the previous owner didn’t think it could be repaired. Lowel
Yeah I know: The critics will say it never had a chunk gone because I failed to take a ‘before’ pic. I fitted the piece of foam, hand shaped and filled as necessary. Then covered with 4oz, hot coated and sanded. Sprayed with a white latex primer I get from S&W, then put another 4oz over that’. I used Vectot Net under the 4oz to strengthen and distract from the repair. The bottom was double 4oz with white primer. I used a full tail patch, not footballs… the center fin was busted out too. I put it back in the same whole with filler and 4oz. Lowel
Looks good McDing! I’m gonna cut out scrap foam and fit it lin place like a lot of you suggested. Also this is my first time doing something like this of this magnitude. I know I’ll mess up along the way but I’d rather mess up on this than a brand new blank, or a nice board that needs a strong repair. I’m looking for experience here, not perfection
Ok. Experience is good. You can glue in the pieces of foam with white Gorilla Glue or just about any kind glue. Yes S&W still has their liteweight Spackle. I actually used some on the above repair. Just always be sure that it is 100% dry to the core. Sands and shapes easy.
