I started to remove the material around an impact crack that I thought was going to reveal the full carbon layer was broken and would require new cloth. But after removing the raised pieces in a small area (~1 sq cm) it looks like it’s just the top layers of epoxy. I think that would mean the top layers of epoxy delaminated from the cloth?..which seems odd but maybe water separated them? At first I thought the cloth looked fully intact but if you expand the pic you can see some fibers are
cut (circled in red). There’s a very small spot that seems like the EPS foam was dented, so some flex in the cloth at that spot (less than 1/2 sq cm). You can see some other cracks in the epoxy layer that I’ve yet to remove any material. Is it worth trying to repair this using only epoxy (carefully remove material around remaining cracks trying to avoid cutting fibers and sand) and not make it the bigger job of removing more material and laying one or two new layers of carbon cloth? On tail of board.
Wet out the glass with epoxy. Within the cure window of the first application of epoxy, fill the weave with another application of epoxy mixed with 20% microballoons/Q-cell, depending on where it is. After it cures, sand and apply another clear coat of epoxy if you want it to look prettier.
With all kind of repair, the golden rule it to do it good and do it once. I would not try to half-ass it. You are gonna end-up having to re-do the repair and that suck. Plus straigh-up epoxy will crack or peel-off.
Here what I would do :
If the lamination as some flex, you need to remove-it and the loose foam too.
Replace the foam with microbaloon or expanding foam
Sand the foam flush and all the area with crack. If the crack have no flex, no need to sand away the cloth.
Laminate over the whole thing with a small patch of 6oz FG over the microballoon/foam and a bigger 6oz patch over the whole repair.
I agree the best approach is to tackle it the right way the first time. Despite that, I need to build my experience on repairing so I don’t mind if I have to redo it. I’m as interested to get some learning on how much these boards flex. It’s literally a couple strands that “appear” to be broken. It feels like there’s a reasonable chance the surrounding intact fibers will hold the tail without flex, so I’m probably going to give it a try without removing and replacing cloth. We shall see…decided it’s worth the learning experience.
But know that the problem is not the tail flexing but water making its way into the foam making the board heavier and degrading the foam until it no longer support the fiber and thus making the problem bigger than it innitialy was.
Thanks. I appreciate the help and the insights.
Going to ask a question to help with my learning…
I thought it would be flex caused by not removing cloth and properly refilling the foam dent that would potentially cause my repair to crack which would then lead to water getting in.
Just hoping to understand why it’s not the potential flex that would lead to a crack that would then lead to a water problem.
If you have time to explain if I’m missing something that’d be great. No worries if not.
I hear you though on the water… it’s very much my concern. I’ll be watching closely for any cracks in my repair to develop and then I’d move to a cloth patch repair.
Thanks.
PS - the size of the foam damage seems to be about the size of a small pea. I’m hoping I can force enough epoxy behind the cloth to backfill the small dent and remove any potential for the repair not to act like the original layup.
I misunderstood. It’s indeed the flex of the board that is going to expand the cracks. I tought you were worried about noticing a flex difference in your board.
Its that flex that is going to make the crack work and lead to water intake. Rotten foam will make the matter worst. If you just fill it with epoxy, the epoxy is going to crack too. To me, the “V” crack on the left of you red circle look like the cloth is also compromise there and will also take up water.
If it was my board, I’ll do a proper repair and forget about it. I hate having to watch after a ding. Plus the ding is close to the leash plug, I would not want it compromise.
If you still want to just put epoxy. Watch the repair after your sessions, watch for it bubbling or for salt-cristal depot. If you want to do a proper repair, I didn’t saw how small it was. No need to replace foam. Just sand-it, laminated-it and fill-it.
Newbie question… By “bubbling”, do you mean bubbling when the epoxy is first applied? Does the bubbling mean there is moisture in the board that is evaporating through the curing epoxy? I just did a small repair and the epoxy was forming large bubbles when first applied. I know that I mixed it too quickly but the epoxy was not bubbling in the mix cup. It was only bubbling when I applied it to the repair. I didn’t think water could be a factor because I had caused the damage on land and had not put the board in water since. Now, I am wondering if water got in through another route.
If you were repairing with a layer or two of carbon would you still add a layer of glass on top? Ive repaired a bunch of boards and typically just layer some carbon without glass, but from your post it sounds like I could get a cleaner result with another layer of glass.
The thing with EPS board is that when there is a difference of temperature between the inner board and the outer environnement, there’s also a difference in pressure resulting in sucking or pushing water/air in or out.
Typically, when you get into the water with just a small hole or crack in your repair, the water is sucked into the board. When you get out of the water and the board heat up, it pushes the water out that can create bubble or salt residue.
In your case what I suspect is that your working environnement was way warmer than your board. So as your board was heating up, it pushed air (or water) out creating bubble in your epoxy,.
Absolutely! Just to aide the wet out and serve as a sacrificial sanding layer before hot coat or paint. I would typically do the carbon patches largest to smallest, then a larger layer of 2oz glass covering the whole repair, then when all that’s cured enough that it’s firm but still Tacky do a round of fairing compound
I found a pretty good method that fast and can look good. I use a few layers of carbon - enough to leave plenty to sand back as I fair it in.
I masking tape an area around the repair, then sand back whatever finish is there around the problem area - to the raw carbon underneath. Mix up some epoxy and cut some small patches of carbon to cover it, largest patch first, then smaller last. Wet it all out pretty wet.
Here’s the fun part - I use clear packing tape over top of it all, wrapped on tightly. Use long strips that sticks to the masking tape area and put it on tight to level out and squeeze the repair. Sort of like a very simple vacuum bag, but without trying to use peel-ply or breather.
If you don’t get air bubbles under the clear tap, its a quick job to pull off the packing tape, masking tape and sand it smooth because it is already pretty clean under the tape
