Whelp, 6 months into enjoying my first Compsand and here’s a nice delamination. Right where you’d expect it to be, under my knee from duck diving (I should know better). Seems there is quite a bit of delam. Deck moves about 1/8" or more from finger pressure. Looking for the repair method. It is water tight right now so I’m half tempted to slap some traction on there and call it good. Only thing is I don’t care for traction tops.
Any ideas out there?
Any body else run into this?
I was thinking it could be:
didn’t let it cure long enough in the bag
the concave deck makes that area higher than normal, soft foam
not enough re-enforcement (4 under, 4 over the balsa all the way around)
I had to put a “scab” in where I had a hot wire burn through
if you care about the board, dont traction pad it, it may get bigger and encompass the whole pad . . . then you’ll really have fun.
fix it . . . depending on the size you can poke a hole in it, and pump it so it sucks in resin (make a pool of resin), and gets the air outside. If it stays down, great, if not, get a weight, cover it in wax paper or slick plastic (I used hard drive static free plastics), saran wrap . . . and put it on the bubble to squeeze it down while it cures.
if its a large delam like several inches in diameter, it be easier to dremel slice the edges open, resin and stick the cloth top down and then put a thin layer of glass over the whole area.
causes . . . hmmm maybe one of the compsand ninjas can answer that . Spackle is the creeping evil and if its laid too thick . . .
Usuallys the delam is created from air expansion due to heat. The expanded air will find the path of least resistance which will be where your core has been compromised (ie feet or knee compressions). Depending on your resin use on the inside lam and the amount of spackle used to seal the blank will determine the nature of the delam. Most of the time the delam is from the eps seperating or shearing apart not from the eps separating from the inside lam. Excessive spackle and a 1:1 resin to glass ratio could have adversely affected your bond to the eps.
everything christian said, for sure. venting is a pretty big deal, especially with a light core.
also, I wouldn’t recommend the “resin shot” idea, as it’s quite likely that the resin will simply slip into your light foam core.
Expanding polyurethane glue, like Gorilla or Elmer’s Ultimate is ideal for this kind of repair though. Drill a couple of holes, squirt that stuff in there, put your vac bag over the whole board and pull a light vacuum to get the skin back down in place. A large syringe and large bore needle is the best application tool as you’ll be able to inject the glue specifically where it needs to go. As the glue cures and expands, it will bite into the foam a bit, likely stiffening the board some, but not alot, and give you your adhesion back. Also, as the repair will be on the deck, once you’ve shot the glue in, get the board upside down as soon as possible to minimize glue seepage into the core; you really just want it between the break, and nowhere else.
Thinking of drilling/routing a hole in the bottom of the board, directly beneath the delam and pouring either 4# or 8# pour foam in there. Just kinda take a pencil or something and push the deck away from the core a bit, let the liquid get in and around in there. The same way you do a leash loop through a fin box on a long board. I’m thinking all the expanding foam will come right back up my access hole.
What about that? It would be stomp proof then for sure. In fact, that stuff is supposed to be waterproof, so just a quick sand and coat of epoxy and off I go.
On that fish it probably will not matter much which way you do it. But if you were doing a lightweight performance board you would want to use one of the other methods. That pour foam will expand all through your core and lock it up nice and tight. Fish were designed to be less flexible so it may even be an improvement.
I’m thinking all the expanding foam will come right back up my access hole.
I have no experience with pour foam, so take this with a grain of salt… but I have heard of a similar ‘experiment’ with aerosol expanding foam, where the expectation was that the excess foam would simply flow out of an opening. It didn’t work, the foam still expanded more or less in place, with disastrous results. I’m not sure how much pour foam expands, but I suspect that if you got it under your skin it could easily expand out more than you want, then stay that way once set.
Its a bit tricky to establish, but you want to see if the underside of the delam is straight glass, skin material, or whether there’s foam attached. In some cases theres a tear in the EPS foam, not actually a delam. This tear is more likely if the delam is a result of non-vented foam. For this example its a bit of a mission depending on the size.
I’ve found a crescent -shaped blade slash kinda sideways into the bubble more effective than drilling for getting inside there. Try to preserve the inner glass layer as best possible. Over a small area the factor of resin drainage as mentioned by Great White, while valid for super-lite freaks, won’t disturb you too much when you just wanna get that ding fixed.
Non-stick plastic under a weight or back in the bag, depending on the size.
The cleanest De-lam repairs I’ve done have been a slash along the skin/rail join line, the blade just sliding along the rail horizontally, open it up, resin in, and either bag it or seal the slash with tape and connect a vac to the vent for suck-down. Using the vent will only work if you have no other breaks in the lamination.
And Grundy’s about right on the pour-foam…jam something that expands under the skin and you may get a hump, and more delam…
If you have a major dent, like serious volume of missing foam, the skin will have to be lifted away. Spackle the void with a mix of EPS beads and resin. Shape this back and re-cap.
Kit, was that the board that you made out scraps and leftover wood. I hope not - it was one of my favorites! On the topic of air damage, I saw Christian’s repair from compressor damage and it looked really good.
Yeah, thats the bitsa board, looks great but was a bit too extremely thin in the rails, for me at 85 kilos. More in the width, to 20 1/2" and it would be fun.
It’s just taking a breather, 'scuse the pun. I’ll have it back in action sometime.
Speedy,
I hear you with the pressure!
I had it as low as possible, but because I was blowing it into a hole I drilled specially, I managed to blow air between the skin and the sealed EPS, so it went BOOM immediately!
dont feel too bad WM, i have delammed a couple of sunovas over the years, its just wear and tear, though it did take longer than 6 months to do, they have both gone in the same area, under that front knee/foot area. I am in the process of ripping the deck of a 6’6" and re doing it.
