Repairing a surfboard...tips?

Been there once. My string ripped through one of my thrusters years ago.

Seems like you have the right materials. Major difference in working with epoxy vs poly is curing time and sanding. It usually takes 24 hours for it to cure hard enough to sand. So be patient. Also, any loose fiberglass and foam must be sanded or dremel (my personal tool of choice for ding repairs) before applying. Open that crack up slightly more with some sandpaper or a dremel and drizzle resin into it and layer it up with cloth. Its easier than it seems. Do it in small amounts and make sure your mixtures of catalyst and resin are exact. Build up the new material and sand it flush with rest of board. Epoxy is harder to sand than poly so dont be scared to be too aggressive with sand paper grit, but stay cautious, and be patient, because of epoxy this repair can take place over a few days to a week if you want it done right only because of the curing time.

Just go for it.

 

First, be sure your blank is polyurethane if you bought polyester Ding All resin. If you bought epoxy Ding All, you can use it no matter what. Usually, but not always, epoxy resin is used to glass over polystyrene (EPS) foam. If so, you MUST use epoxy resin. You can use polyester resin to repair an epoxy or polyester lamination, but only if the core material is polyurethane, and NOT polystyrene. You can tell polyurethane foam from polystyrene foam by looking at it closely... polyurethane foam will be crispy and crumbly; polystyrene will be little beads (EPS) or tough and kind of rubbery (XPS).

Put your board on the rack bottom up, and level the damaged area. Remove any loose fiberglass and sand. Tape off the deckside slice with masking tape, wrapping the tape around the tail rail and ending at the bottom edge of the rail. This prevents the resin from running through the slice and dripping out the other side. Mix your resin and hardener and some filler material... either q-cell or microballoons or cabisil... to make a thick paste that barely flows, and pour it into the slice to fill up the gap to the level of the flat bottom. Don't use too much or too little. Just fill the slice level with the bottom of the board. Let it cure. Remove the tape, sand the area around the slice, and laminate a patch over the bottom side slice that wraps around the rail to the deck side. Let cure; fair the edges of the patch. Flip the board and do the same to the deck side, wrapping the patch around to the bottom. Let cure; fair the edges of the patch. Tape off the bottom edge of the board, deck side up, so the tape hangs off the edge and forms a drip edge. Paint a hotcoat over the patch; let cure. Flip. Do the same to the bottom, taping off a drip edge, and painting a hotcoat over the patch. Sand smooth. Done.

 

I've never had good luck snipping up fiberglass cloth to thicken up resin. It's hard to describe what you get from doing that, but stringy jell-o might not be too far off, and the problem is sometimes it just wont flow at all, so you might have a hard time getting it down into that crack.

q-cell is the right stuff for that job, and if you go to a surf shop with that does real board repairs, with a few bucks, and a ziplock baggie, my guess is you'll come out with a half cup of q-cell, which will last you this repair and the next half dozen. If you do get some, handle it carefully...its nasty stuff and gets airborne easily.

if getting to a surf shop is not convenient for you, my guess is there are plenty of "home substitutes" for q-cell, but i've never tried any of them so i wont speculate.

 

Q cell. Only way to fill it. Just don't mix it too hot.

Greenlight in Manasquan has the Free ding repair classes on Saturdays, might be good to go there first...

 

Q-cell and microballoons/microspheres are hollow glass spheres used to make resin more viscus while making it lighter and easier to sand. Cabosil is also a thickener, but adds strength, so it's harder to sand. All of the above also make the mix whiter so the repair matches better. Chopped strand is harder to work with, like Mitch said, and makes it harder to sand as well. You can get filler material at you local surf shop/ding repair guy, like the guys above said, or you can order it online. West Marine and other boating supply places carry it, but it's really expensive there. You can do the repair without it if you have to... you'll just have a clear repair. Just don't over-fill your hole so you have nothing to sand before you laminate. The only substitute I've tried it talc, but don't worry about that...

A hotcoat is a coat of catalyzed resin painted over the laminated patch. It seals the repair and gives you something to sand when faring out the repair and blending it into the surrounding area. It's referred to as a hotcoat because it's usually catalyzed "hot" and kicks quickly. Use just enough to make the weave disappear... not a big, thick puddle that you'll have to sand all off anyway. Taping around the repair helps keep the resin where you want it. Pull the tape once the resin starts to gell.

Paper dixie cups or cut off water bottle bottoms work fine for mixing small amounts of resin. Follow the manufacturer's instructions on how much catalyst to use. You can eyeball ounces of resin and count drops of cat. If you're using filler material, mix it into the resin first, then catalyze.

 

a tip- specially if using epoxy- the stuff is super runny... use alot of masking tape, even when preping/sanding the area- mask it out, like LBcrew mentioned... the repair will look much better. Use the tape to create a cup on the bottom to catch excess resin and to keep the resin inside the ding when trying to fill it- gravity has its way sometimes... dont worry if you end up with alot of resin built up when trying to keep the resin inside the ding, you can sand it off. AND- like LBC mentioned- MAKE SURE you take OFF the masking tape right when the resin starts to cure- I like to wait till right after it gels- then your a knife to score the area and take off the tape- otherwise it will create a mess. Don't cut/sand too much of the area away before filling- there is a balance- when you take out too much is could create more problems. First fill the ding with your choice if filler- its so small, I would just use resin, plus it gives more strength. then sand it down to just below flush- then add a layer of fiberglass, then sand careful not to sand away all the fibergalss, then hotcoat with a paintbrush, still masking out an area everystep of the way. sanding could be the most important part to making it look good.

 

the blue ding all bottle is for epoxy and the yellow is for poly. Make sure your using the right stuff or your foam will melt! Determine for sure if your board is EPS or poly. I forgot to mention the cabisol as a filler, but don't use it as a top coat.

 

I've got a question about delamination.

I've got a longboard that is old and has a area about 12'x 16' inches that's delaminated .
Looking at injection as the easy option. Going to make 8 small holes and fill it untill it oozes out the other holes then put a weight on it overnight then sand and finish. Or just cut out the delam and fill it then apply new cloth resin and poly
Never tried the injection method and let's face it I'm a marginal repair guy at best. Kind of a cave man. I know you guys got the goods so let me know what you think bout that. Remember I'm lazy and expect good results

 

The method that I was taught is to attack the delam one side of the stringer at a time.

First use a dremel type tool and cut through the glass along the side of the stringer where the delam is occurring.

Then carefully pry up the glass, which shouldn't be hard since it's delaming, and use compressed air to blow out any loose pieces of foam.

Next, set the board up on it's rail so you can pour catalyzed laminating resin down into the cleaned up delam area.

Pour it in and squish it down as far into the board as you can. Set the board flat again and press on the glass to squeeze out any excess. You don't want to have a bunch of resin between the foam and the glass for weight and strength reasons.

Wipe off any excess resin and take some wax paper and put it over the cut you made with the dremel (be VERY careful to make sure it's wax side down). The wax paper will simulate the wax additive in sanding resin and will help the laminating resin cure.

Last, use some sand bags, bags of dirt, whatever you have that's heavy and will take the shape of the board, and weight it down and leave it for a day.

When you have both sides done, put a patch of cloth over the incision on the stringer and seal it up like a normal ding.

 

Thanks. I'll do just that. It's better than buying a board and it will give me some experience.

 

If its on a part of the deck where you would be standing, the injection method isn't something I would do. If you think about it you are just introducing a 1/2 thick (the foam is almost always caved in under the delam so there is usually kind of a basin in the deck that will take more resin that you think to fill) big pool of hard resin under the glass, and this will just create a hard object to hasten adjacent delamination.

The method above (cut semicircles, lift flaps, apply lam resin, apply weight to flatten, then patch over is) is better.

IMO, the best solution is just cut out the bad glass entirely, mix lam resin and q-cell into a thick foamy milkshake and fill the low spots, sand flush, then apply a patch over the filled around with two layers of 6 oz cloth, then hotcoat. It might sound harder than the lifting/laying the flaps, but actually isn't much harder and might increase odds of success.

 

Thanks for the advice. That's a more specific solid approach. This board has several areas to work on and I'm not sure how deep I want to get into it but I need to d cide soon. It's almost surf season