I did a couple of repairs recently to boards that had bad cases of stress cracks. Both were longboards and both had dozens of stress cracks lining the entire front third of the bottom of the board. Deep brown streaks presumably from water seepage. I wasn't really sure how deep the cracks were...whether it was really possible to do much about it without stripping the glass of down to the foam, which wasn't going to happen.
Here's what one of the boards looked like in the stress cracked area:
The repair involved sanding off the hotcoat, and as it turns out the cracks were mostly in the hotcoat and so was a lot of the brown color. Sanded down to just touching the weave and the cracks mostly disappeared and so did a good bit of the dark brown. Glassed a layer of 4 oz cloth over the sanded area for good measure, reglassed, hotcoated, sanded. Board looks a lot better.
Same board after repairs...tried to duplicate the shots for comparison. Its still got some beige left, the cracks are pretty much gone, and after four hours of work, the board is probably a lot better off for it.
Last edited by mitchell; Sep 22, 2013 at 04:45 PM.
Wow... good job man! Went a lot further than I would have. The remaining brown is probably in the foam. Looks as if it may have soaked up a little water. You have to remember that foam is just like a sponge and as soon as it gets the chance to touch water its going to soak it up. You can dry it out but its still going to remain yellowish brown. The sun also does quite a bit of yellowing damage... but in your case it looks like from water. Next time you have a custom board built if you don't want it turning on you have them paint the blank. It will cost a little more, usually bout a $100 to do so.
If you notice a lot of the new epoxy boards like firewire etc... paint their blanks. Its because of the cloth they use. Its super strong but they can't get it to finish bright white so they have to paint it. Nobody would buy a brand new yellow board! I have built boards with hemp cloth and it was super strong but also had to paint it because I just couldn't get it bright white. You can bleach the cloth beforehand but it weakens it immensely.
Also there is a new cloth being used which is bullet proof if layered right, problem with that cloth is its super tough to trim and its very, very shifty... hard to lay on board. A few board builders use it and though it finishes bright white you can see the weave and how wavey and crooked it got when glassed. So once again, they paint it.
Looks as if those cracks are a result of the nose getting buckled. Kind of like as if the nose went into the sand bar, unless it was a really serious wave. Fortunately its a tough board and didn't break, just got some stress cracks.
thanks for sharing, my lb looks just like that and I been trying to decide what to do. now I know.
It's a great idea to sand down to the weave or strip the glass - hopefully the board was dry where you put the patch of glass that I see you put in, otherwise, it might still crumble inside (if you had enough sense to sand down to the weave, you probably had enough sense to dry the board). It would be a shame to have to do the repair again 3 years from now but I would guess you'll be good to go for a long time either way! I just glassed a whole new bottom and wrapped the rails and my board looks great, but I am relying on the quality of the underlying glass which is sometimes questionable.
how do you glass such a large area without letting resin spread all over the board?
Just taped off the area to be glassed with 3inch masking tape so the little bit of resin i drew out of the cloth accumulated on the tape or dripped over the rails. The board was dried out. Lightly glassed, performance longboards seem kind of susceptible to these stress cracks... I guess they tend to flex quite a bit and I'm sure it was slammed into the sandbar or involved in some mayhem... not sure, it's not my board.
Last edited by mitchell; Sep 23, 2013 at 02:36 AM.
I used to sand through the hot/gloss coat to weave and brush on a bit of styrene followed up by basting the repair with resin and the laying glass down while wet. Styrene thinned out resin enough to penetrate the cracks and glass strengthened the repair. Usually didn't matter though...damage is done. They'll likely return with the next hit on a sand bar, beach, etc.
Repair looks great Mitchell...regardless of the water damage...