Not curing long enough was my first guess.
Not that you'd want to do this to a new board, but couldn't you try the hair dryer trick to maybe warm up and pop those dents back out? I think it was McDing that suggested this technique (although, not in this thread).
Send me your dinged, damaged, and yellowed.
Never tried to use a heat gun on a glassed board and don't know that it would work. I have used heat guns and blow driers to raise dents in unglassed blanks. The technique consists of making a pass or two over the dent with a heat gun. A blow dryer is better because it doesn't get as hot. The other trick is the old woodworker trick of applying a folded damp cloth on the dent and then running a household iron over it. The heat and steam raises the dent. The problem with the heat gun is that if you hit it too much the foam will burn or turn brown like toast. So be careful. This is the reason I like to keep an old "Goodwill" blow dryer around the shop. Doesn't get as hot. You've got me thinking. I may try this on a glassed board. I would think if you were careful, it might work. These little tricks with the blow dryer and iron, don't work on EPS.
Thanks for all the replies. I won't be able to ride it for another week at least due to lack of waves so I think only time will tell. If there's no more unexpected dents next time I surf, it was most likely cure time. If there is, the blank is most likely to blame.
@monkstar1 I've read about this hair dryer technique, and I've pondered it, but I've also seen some warn against it as it could lead to delam or further damage. Heat is generally an enemy. I know with the technique you apply localized and indirect heat while rapidly waving the heat gun or hair dryer over the spot, but it seems a little sketchy...
Has anyone ever had success with this technique other than taking small dents out of shaped foam before glassing?
Yeah I think you just need to let it cure a week. There is one brand out of the big three that is softer than the other two; I won't name it on a public forum, even though I think I have done so in the past. Do your research.. Hint; Who has the closest conection historically to Soft Clark Foam?
It's been many years since I'ved used PE, but I've been told before that the obvious VOC smell means the resin is still simmering and hasn't reached it's "full-as-it-gets" hardness. Like the others have said, if the shaper took a bunch of thickness off the deck instead of the bottom then the core might be sensitive to pressures.
As Lowel says, try an iron and a damp cloth, the temp won''t get over 212°F/100°C, If it does anything, great, if it doesn't, no harm-no foul. I have done that in the past, mixed results. Sometimes it worked, sometimes it didn't.
As you say, it's kinda sketchy applying a lot of heat and if you have a delam starting under those dents, crushed foam, well, it won't be just starting any more. Better to have the dents. Throw some deck pads on it, call it a day.
hope that's of use
I haven't made a PU/PE board for years, but I remember seeing a 2 week wait for poly resin.
9 days from shaping to riding doesn't leave much time from when the board is finished being glassed till you used it.
As a comparison, I've made 2lb EPS core with 3 layers of glass on the deck, and after the first surf, I've had dents.
That's the nice thing about UV. Ride it th same day you make it. I have shaped a lot of Arctic and Millennium in recent years. A few US Blanks as well. While there are differences in all three foams and the way they shape; cell structure throughout these blanks is consistent. The old "don't take too much off the deck" problem is a thing of the past and primarily a Clark Foam issue. Some of the lighter formulas do dent. The lighter the foam, the weaker the cell structure. Millennium's red is their lightest foam(they make one lighter for Pros). The original Red would dent pretty easily. But a couple of years ago they reformulated the red foam and now it is great. They describe the newer Red foam as less crushable. Most of the Shortboard blanks In Millennium Foam I sell are Red. One shaper buys Red longboard blanks for a "Comp" model longboard he shapes. Artic's Yellow and Orange are also very good lightweight foams. But typically; If you go to a lighter foam blank it is more likely to dent.
I'm only guessing but if you're wearing 7mm booties it's pretty darn cold out. If the board isn't being glassed above a consistant 60+ degrees F it might not be curing hard enough. Plus a gloss coat on top of the hot coat is often disregaurded but I've never had the dents when I do it and I only do 10 or 12oz of fiberglass. I'm 195lbs with 3mm booties and our fall/winter air temps are in the 40s and 50s. I'd be real nervous about a hairdrier too, I've seen them make bubbles bigger than softballs when gas gets trapped inside. Did that one myself on a repair job... dremel time...