Ahoy fellow swaylockians. So one of my homemade boards has a whole bunch of stress cracks on the bottom after my latest session. I was surfing a shallow beach break break but the waves were not that big. Are there any building mistakes that could cause a board to crack like this? Any tips so that my future boards will be less likely to crack like this? It is pu foam and Uv Poly resin. Also the blank was from an old 60’s longboard that was trashed so I shaped this out of it. Hence the brown spots and water damage. Also the foam was outgasing on me hard when I was glassing. Blowing bubbles right thru my hot/glosscoats. So the board was never really watertight considering all the pinholes. Thanks y’all!
gotta quit bustin airs like a brazzo!
Haha good point Huck. My air game has been pretty mental lately! Not
maybe its that huntington hop thing?
3 stringers, man, oughtta be bulletproof! How thick is the board?
It took a pretty hard shot to make those cracks. What was the glassing schedule?
heavy 6’8 Single fin so no hopping haha. I was riding in a pretty punchy kinda shore break so it very possible it hit the hard sand bottom pretty good. but I’m still surprised at how cracked it was so figured I did something stupid when building it that jeopardized its structural integrity. It is 2.75 thick and glassed with all 7.5 oz volan. If you notice on the second pic the center stringer is actually two different pieces of wood joined together underneath the blue resin band. The balsa in the original T-Band was rotten in the front half so I cut out the stringer in the front half and replaced it with with a piece of 3/4 cedar. The resin band is there to cover that joint. Do you think this could have anything to do with it? I figured that the outboard stringers would keep the board from flexing too much but maybe I’m wrong.
Well people have been snapping and buckelling boards like that for a long time so I wouldn’t take it personally.
If you did do something wrong it might be that you added too much MekP. But other than that though just understand that theses things happen.
yes
I have a 9’4" PU/PE high performance long board that has stress cracks like that all over the bottom, way more than your board. I don’t know how they got there, but the board has been in solid overhead surf quite a few times. I haven’t used it for several years due to the cracks, but it’s a really good board. I made a copy of the rocker and outline and have made a couple of similar, but shorter boards.
The board was custom made for my brother, so I don’t know what the glassing schedule is. Maybe from thicker layers of sanding and gloss resin?
sounds good ya’ll. i’m just gonna keep riding it!
Hey Sharkcountry,
I did some research a found that too thick a hotcoat or glosscoat can make a board brittle. yea Perhaps thats the issue with our boards.
I am curious about the whole outgassing thing. Is that normal for a PU/PE strip and redo? One would think that a 50 year old piece of foam would be ‘done’ outgassing. Could that leave moisture or maybe some reaction between old foam and new resin as the culprit?
you don’t see this kind of thing so much with epoxy resin, more of a poly resin thing methinks.
Yea the outgassing thing was really strange. I stripped the old board, cut out all of the rotten bits of stringer and then it sat in my basement for about a year. Everything was super dry as far as I could tell by the time I got around to shaping and then glassing it. I even glassed it on falling temps. The intial hotcoat was a bubbly nightmare. I sanded it all down and re-hotcoated and was still bubbling up like crazy. tried to plug the pinholes with superglue once it dried but air was even getting blown up through that. It was really crazy and a huge pain in the butt. If you notice there is one orange spot on the resin band which is where one of those massive pinholes is. Just kept blowing bubbles through my pigmented resin band. Eventually I was able to fill some of the major pinholes with superglue before glossing the board but air was still getting blown up through my glosscoat. Eventually I said “screw it” and just started riding the thing. Still a mystery to me
If you don’t mind, why don’t you post up a pic or two of the whole board before she goes completely to pieces.
another one. I don’t know why they keep coming in sideways.
(moderator note: cuz you’re on the sideways part of the planet. or maybe just the file was too big - resized it for you)
It looks as if you have a very flat deck on that board. Flat decked boards bend a lot easier, which leads to snapping.
Domed decks don’t flex as much.
The deck is very flat. That is good to know. Thanks Sammy.
Cool stick.