Hello All, I just picked up a 9' G&S Peak Performer that has half a dozen stress cracks about 2' back from the nose spaced several inches apart from each other all the way across the bottom of the board. The cracks do not "appear" to go as deep as the cloth, and they do not go into the rails, and the lines of the board have not changed due to the stress cracks.The deck has a few heal dents, and minor dings, but it has no water stains, and other than the stress cracks looks fine.
I suppose typical of newer production boards it does not have a heavy glass schedule, which I am not too crazy about, but it is what it is.This is a polyurethane foam board, and I believe polyester resin.I wrote to G&S asking about the materials and glass schedule, but have got no reply so far.
I want to fix the stress cracks before they become a more serious issue.I have thought about a number of fixes, but would like someone with more experience than myself to share any advice that they are willing to.I want to make a good durable fix and some options that I have thought about:
1.Grind/sand out the cracks down to the glass and fill with polyester resin (perhaps epoxy??) hot coat and gloss.
2.Grind/sand feather edge cracks and glass in a layer of 4-6oz cloth, hot coat and gloss.
3.I’ll probably get hate mail on this option and it is probably way more work than it is worth,…. but I am not in love with the light glass schedule.Sand deck and bottom of the board most of the way down to the cloth and add a layer of 4-6oz cloth with Epoxy Resin…..
I would appreciate any constructive ideas/advice that any of you can give me on this repair.
If the board has a poly lamination then I wouldn’t suggest an epoxy patch due to adhesion issues. In your place I would stick with polyesther or vinylesther resin for the patch.
Would you recommend just sanding out the damaged polyester and filling back in with polyester resin only, or sand down the entire area and adding a layer of cloth? When stress cracks occur, does this damage go all the way through the cloth even though it does not appear to?
It looks like if I only repair the cracks (no cloth) that I should stick to polyester, as the mechanical properties of epoxy being more flexible (more elastic) the board might be weak (behave differently) in those areas (hinge) due to the epoxy. Now if I sand the resin down over the entire area with the damage and add a layer of cloth it looks like I could go with polyester or epoxy.
Most of you guys have a lot more experience at this stuff than I do, so you guidance is appreciated.
In my experience (which isn't a lot), cracks that form in the case you have described are usually in the gloss coat, assuming you have a gloss coat of course. Because there are no reinforcments in a gloss coat (cloth) When the board flexes there is nothing to hold it together. Its a bit like concrete without reinforcments, any movement and it cracks. Also, have you ever seen the spider web look on a glossed board after it has been dinged? same principal. If you sand the cracks out and re apply poly, you will end up with more cracks as the board flexes again. Epoxy does have a bit more flex but thats not to say it wont crack either. If you puy down a layer of cloth, you still need to fill coat it, sand it and apply a gloss coat to blend in with the rest of the board. Again assuming it is glossed. Then you are back to where you started. Unless there is any damage to the actual lamination, I wouldn't worry to much about it. Surfboards are not made of steel. They do tend to take a bit of beating and they hold up quite well considering. I remember when I finish my 9'2" longboard a few years ago. First wave I pearled it, popped up and my brand new board smacked me on the head and put a ding the size of a tennis ball on the bottom. 5 years later, its still there and it now my go to board.
IMO the lack of replies is because no one fixes stress cracks :-)
If you really like the board and feel it will ride better with more weight, go ahead and re-glass the whole thing. Keep in mind that your finish work may not be as good as the pros, so the board may lose some value. Doesn't matter if all you want to do is ride it...
If you re-glass whole or patch, paint the cracks (sanded as deep as you dare) with pure styrene right before before you put cloth on. You could also bend the cracks open a bit when you put on styrene, need a helper for that.
I may go ahead and just sand the polyester down to the cloth at the stress cracks, apply the styrene to the cracks and poly; then gloss coat it and see how the repair holds up.
If the cracks re-appear in the same locations I may have to take the more drastic additional layer of cloth route.
If you sand the cracked area down to the cloth/weave, then you’ll be sanding away the cracks, too. So, the idea of styrene as a filler is moot. As others mentioned, the cracks are most likely in the gloss coat and not in the glass itself. The simplest fix is a light sanding and apply a coat of sanding resin that’s been thinned out with styrene. The down side of that approach is the more you thin the resin the weaker it will be, and you’re going to have cracks recurring. Kind of defeats the whole thing. If the cracks really bother you, then do a patch with lightweight cloth. 2.6 oz or so. Do you know how to do that?
Sammy, most DIY'ers aren't going to lean on it near hard enough to sand out all of the stress cracks. That's why I suggested hitting it with styrene before adding cloth.
I know how to do the cloth work, not professional but can do a reasonably respectable job. The stress cracks are 3-5" apart, would you sand down to the cloth only in the area of each crack and put a piece of cloth wide enough to cover the board but only long enough to cover each individual crack, or would you grind down to the cloth over the entire damage (all of the cracks) and put one long piece of cloth?
I think that I can grind most of the way down to the cloth, just not into the cloth, to do the resin only approach. But at the same time, if it is only going to crack again at the same location I would rather go the cloth route....
Am I peeing in the wind to expect the resin only approach to be a good long term fix?I appreciate all of your input.
Based on feedback of several much more enlightened individuals than myself, I used a 5" orbital sander and by using the sander slightly on edge sanded all the stress cracks, holding the sander on a slight angle cut a slightly concave troth about 1 to 1 1/4 inch wide through the gloss coat, and just into the underlying fiberglass cloth. I mixed some laminating resin for slow cure, applied some liquid styryne in the cracks and brushed a thin layer of laminating resin over the crack/troughs.I then laid 2 strips of 4oz cloth in the troughs; bottom 4oz strip about 1/2" wide by length of trough, and top 4oz strip about 1" wide. I allowed this to cure and lightly sanded these layers somewhat flat, and then gloss coated.
The board has seen a fair amount of water time since then; up to about 7’ waves and no stress cracks have re-appeared.This feedback is just to say thanks to all the people that offered advice.