Repair Delamination

Anyone got advice on how to repair delamination?

I am thinking of drilling a grid of small holes and using a large syringe to inject epoxy. Then quickly roll the board around, tapping it up and down. Then "popping" the delaminated section up/down. All to get the resin spread out as far as possible. Then weight the board with bags of potting mix or salt and hope it sets back in full contact with the foam.

be careful with what epoxy you use ,
i did a rushed repair the night before a race with West 206 and ended up with a big cavity instead , there is nowhere for the heat to go and you will be pumping in alot of resin.
normally it has worked fine for small repairs.

looks like a big delam ;
maybe consider cutting and peeling away the delam skin and sticking it back down with epiglue or similar, then you can be sure that you have proper coverage.
a mate did this with a sup and it went ok .

yep, be interested to hear from others who have done this.

Depends if we are talking PVC layer delam, or only the outer glass......? If the latter, it is much easier as you only need to get a small amount of resin between the two and then hold it down.
Former far more common unfortunately.

Then, is the shape still the same (vee, concave?) or has it curved outwards. If the latter it will need weighting.

Remember styro sucks up like a sponge so lots of resin injection and the board upside down will not achieve a lot. If its a PVC layer delam we need to inject lots of holes, tape over them and then placed right way up so the resin spreads out over the whole bottom laminate instead of just disappearing into the middle of the board. (if you deconstructed this method later you will see lots of pillars of resin soaked styro with not much bottom adhesion at all. Holes to the bottom is a much better result.
Now that is fine if the bottom shape is unchanged, but if it needs to be pushed back against the core then we need to vac bag it (can't weight the bottom whilst its right way up..... so a dilemma.....

And yes super slow hardender..... do it in the evening .... let it sit couple days to be safe

also a lot depend on the condition of the core. Some of the repairs I've done, the core has broken up, leaving bits floating around inside. you can't just cut it off and glue back down, or inject and weight either, the bottom shape would be haywire. The whole section needs the core routed out to remove damaged foam, new foam inserted and shaped, it's vaguely possible you could reuse the old laminate, but I've never managed it, always had to make a new one.

^^ I don't think that's a logo on the bottom

www.seabreeze.com.au/forums/Windsurfing/Foiling/Foil-board-Repair-Job-The-new-nose-you-all-need?page=1

^^^ Not for an area that size. You can't maintain the rocker it will be wavy due to the pressure

However as this is a foil board the bottom is not so relevant, and its knocked about too, so maybe in this case

I've done a delamed deck with the drilled holes, epoxy and sandbag thing (concave deck so I needed to press it back down). It was late autumn and used slow hardener so that helped. A few years later, things are still okay although I'm more careful to let it vent on warm days. Like yours, mine was a foil board that had had a few misadventures. My foam seemed to be in good shape and it didn't take that much epoxy. Drill the holes shallowly so you aren't injecting epoxy deep into the foam instead. It travels pretty quickly along the surface. I think I did holes 8-10cm apart. Board isn't nearby but I'll check the distance if you need that info. mark_australia's tip to turn it upside down is great - wish I had had that option as I needed to press the deck back down and lacked a vacuum at the time.

If you feel the foam is in good shape, no harm in trying, I'd think. It'll quickly become apparent if you need to peel the whole thing off and start fresh.

Cut the delam out and reuse it if the core is solid, replace if you have to. Here is inexpensive vacuum pump
www.harborfreight.com/25-cfm-vacuum-pump-61245.html
compositeenvisions.com/product/vacuum-bagging-starter-kit-947/

Add a gauge and a relief valve. Put these inexpensive pumps outside the shop when running, they burn/vaporize oil. Pass the hose through a window or door. A collector pot is nice but not essential for repairs. Don't suck water out of a wet board unless you have a collector pot. When you first turn on the vacuum you can let the pressure drop to 25 psi for a period of about 15 minutes (depends on board volume) then you need to use the by bass valve to keep the pressure at 10-15 psi for the remainder of the cure. The preasure will not crush the foam at first but eventually the vacuum hauls all the air out of the blank then it crushes. Using full vacuum for 15 minutes helps compact the lami and get better resin ratios but don't multitask and forget!

That board cost thousands, spend a hundred or two and do it right. You will get a better result and so will the next person that gets that sweet board.

Then, just drill and fill with pu glue or whatever.
I did it to try out a board, worked well. I set something super heavy on it (but ideally you want to respect hull shape!) And did it in 3 steps. The whole hull pretty much. Board had sit on a roof for years...

Sand foam flush then use some kind of waterproof filler then paint

Good luck!

I think you will have a beautiful resin-soaked blanket sculpture

No seriously, hope it works out but very hard to get even pressure all over

Good news.
the Phoenix rises again!
Delamination repaired
But now I have a small amount of cleaning to do. Table cloth worked well as peel ply. (Wish I thought to order some a week ago!).

Just one blob of hard epoxy to remove. All the rest "bleed" into the material and peeled off easily. Except a few small sections where it has stuck.


A hand pressure test across the hull shows no more movement! I just hope it is watertight.
Oout of 400mL of resin probably added 300g weight. On top of prior repairs probably the heaviest FMX ever.
Happy for 2 hours work.