seems like the last few boards I have shaped have pressure dings in them. most just cracks in the hotcoat in a round "bulls eye fasion"some boards have 6/4 oz decks some have 4/4 one has 10 oz pressure cracks in all…should I use heaver glass?slower ignition?wait a month to surf them(yea right).also what is your favorite pair of sissors?
You might be surfing it too hard man. Pressure cracks are inevitable…maybe try using epoxy?
I’m assuming these are normal small pressure cracks and not huge cracks running up and down the board glass.
these boards are being surfed in small shoulder high surf…no air drops…nothing crazy…
If its just minor cracks coming from minor surf, you might wanna try a slower ignition with the hot coat. It might make it slightly more stable, although I would guess it’s completely how the boards are being surfed and has nothing to do with the actual construction. That’s just my guess though.
I’m kinda having the problem with a new longboard that I made. There are pressure dings all over the deck now and I’ve surfed it for about 12 hours worth of surf, mostly in waist high or under. I let the finished board set for over 3 weeks before the first surf. I also saw one on a quad I did, after only one surf and looks like the heel of my foot. I don’t think that I surf that hard, is that I’m setting the hotcoat off too fast?
Littlegrommy, Most likely, you’re shaping too much foam off the deck. Or…you are glassing the deck too light.
Most polyurethane foams are softer toward the center. I find it best to take most of the foam off the bottom when rockering or foiling the board. That leaves the hardest foam on the deck.
Doug
are the cracks indentions in the foam or shatters in the glass? kicking the hot coat resin too hot can make it brittle and could cause shatters in the glass from pressure. try using uv resin and it could stop the problem.
it could be from the cloth your using also. it could have been knocked around in shipping or something, that can caused the fibers to shatter. when this happens sometimes you cant see them until you fill coat and hot coat, they look like spider webs in the glass.
also ive seen spider web shatters in the glass from sweat dripping from my forehead when its hot, or condensation dripping from my respirator when its cold.
any of those things can cause problems. but it could be that you just rip too hard, in which case try using deck patches. good luck
there are indentions in the longboard, but not the quad. when i sand the hotcoat i’ve tried to take a lot of it off, then put a speed spray on afterward. may it be that i’m sanding too much of the hotcoat off? and on the quad i did take alot of foam of the deck.
by sanding off too much hotcoat you weaken the fiberglass considerably. if they are just small spider web like shatters try painting them with styrene before hotcoating. they are hard to see w/o some sort of filler resin but hold them under the light at the right angle and they should be visible.
Las Olas,
I’ll have to respectfully disagree with you on the hotcoat issue.
I used to leave my hotcoats thick, thinking that the board would be stronger that way. But I actually got more shatters and stress cracks (especially on the bottom) with a thick hotcoat.
After reading some good posts on Swaylocks regarding resin, I changed my methods. Here’s what I learned:
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Resin is not strong all by itself. A fiberglass (or carbon fiber, Kevlar, etc) mat has to be part of the equation to get adequate tensil strength. That’s one of the reasons I was getting stress cracks: too much resin, not enough fiberglass.
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3 layers of 4oz. cloth is stronger than 2 layers of 6oz… 3 layers of 4oz. has a higher fiberglass to resin ratio.
I started glassing the bottom of my boards with 2 layers of 4oz. and the decks with 3 layers of 4oz with a 4oz. deck patch. This method has worked out well, along with shaping as little as possible off the deck in order to retain the strongest foam in the stomping area.
I usually sand my hotcoats to the point where I can start to see the weave of the lamination. We call it the hotcoat, the Aussie’s call it the Filler Coat. It seems that filler coat is a better description of what the purpose is: to fill the weave with resin. Of course I always add a Gloss. If you leave a sanded finish on the hotcoat, it has to be a little thicker.
Doug
hey doug,
couldnt agree more. i was thinking that the shatters were in the weave of the cloth and that he was trying to remove them by sanding through the hotcoat and into the cloth to grind them out-thereby weakening the fiberglass. also i was assuming that there was no gloss coat. perhaps that is not the case, in any matter, thank you for clarifying that- i dont want to confuse anybody.
Foam is more then likely the problem. You can apply as much glass as you wish but you can only make a marshmallow so stiff, but a brick is going to be stiff with just a little glass over it.
also something to consider is that small wave surfing kills boards! all the effort to generate speed is denting the sh!t out of the deck. i should know, i grew up surfing in south florida. your so amped when there are little waves you try and surf like occy in 1ft dribblers= beating the poor board to death.
anyways, try putting on a stomp patch next time…should help alot.
Thanks guys, a lot to consider on my next board. Maybe the next board will get that 3rd layer of glass.
One more question. On both boards I glassed the bottom with a color pigment and wrapped it around the rails. Then on the deck I did one layer of glass with a different color (to where the bottom color wrapped around the rail). Then glassed the other layer over that wrapping around to the bottom with clear resin. Could that give any problems, like I’m having? I would think that would be stronger am I right or wrong?
I reckon the cracks are from too thick a layer of hotcoat resin. Not many boards around now that get that onion ring effect when hit, unless there are some serious layers of resin on the board.
There is nothing wrong with the way you have done your lamination with the pigments.
Three layers of 4oz is pretty drastic (depending on the density of your foam).
My latest shortboard is surfblanks blue foam with 2 x 4oz deck 1 x 4oz bottom holding up really well.
Daren
I think your just kickin it too hot
the faster it kicks the more brittle it gets
slow kick will give you a more flexable resin
I had started to have it kick a little faster than before, because it was not “walking” out even. So should I now decrease the hardener?
I would say yes slow it down a bit
Do you meen Tipping out"
I put my sand coats on and try to leave it thick
so I got less chance of a sand through
I use UV cat
pour and brush it on
Tip it out
when its leveled 5 to 10 minutes
I stick it in the sun
On a gloss coat I will use both types of cat
and try to get a thin coat
tip out
let gell 15 to 30 minuites
pull tape
get it in the sun to set the resin
no ones complaned as of yet
your not using gloss resin as sanding resin?
it very brittle
I guess “walking out” is the same as “tipping out” Let the resin flow out? I’m using hotcoat/sanding resin. I don’t do a glosscoat. Would you use a speed spray after a glosscoat? Seems like that would take away from the shine of the Gloss, is that true? I’ve been trying not to put the hotcoat on too thick cause I didn’t want the extra weight, I know I’ll get some replys about the weight not be a big difference. It seemed like there were some replys about a thicker hotcoat won’t add any extra strength anyways.