Hi, Bought a used board. There is a small hole on the back of the fin box, probably someone ran aground with the fin. How can I repair it? I was thinking of putting some epoxy and then putting the fin in with peel ply on and letting it dry. Has anyone tried it? I will taket another picture tomorrow but is in the bottom left side. I d'ont want to change all the box.

Are u taking about where the bottom meets the box? The missing green bit?
if so I'd leave it - a PB is about 6mm thick there, so it's sound from what I can see

plus you won't get resin to stick to it well and your fill will likely fall out

Select to expand quote

Mark _australia said..
Are u taking about where the bottom meets the box? The missing green bit?
if so I'd leave it - a PB is about 6mm thick there, so it's sound from what I can see

plus you won't get resin to stick to it well and your fill will likely fall out

Agreed,

I took more pictures. There is hole in the back side of slot, I have a stick in the picture. They try to repair with epoxy I think but was not a good result. And The box have a vertical crack line (in the carbon). Close to the screw hole is still original carbon , on the side left and right is epoxy. The back side have lika I said a cracking hole also. My plan was to cover the screw hole, put some extra epoxy in the box especially close to the cracking hole and fit inside a fin with peel ply.

Is the hole a problem if the power box is set in high density closed cell foam?

I would push down hard on the repair with a screwdriver to see if its solid. Make sure it's really solid. Any movement and it will need to be removed and a bigger repair. If it is solid, then I would do a leak test. Plug up the fin screw hole on the deck side with a bung. Do up the vent screw. Turn board upside down and fill fin box with water. Place board in sun. You will see bubbles if its leaking. If its leaking, I would paint a thick layer of resin on the affected areas with a small brush. Repeat leak test. If all good, push and pull on the fin hard in all directions and take it for a ride. Repeat leak test. If there is no leak, it's probably OK.

Not worth the risk. That's likely had a fin hit bottom, causing a crack in roof of the box. Replace it as the previous repair didnt work.
water finds a way .. and you don't want a 15kg board

Yip....board needs a new box.

Select to expand quote

Mark _australia said..
Not worth the risk. That's likely had a fin hit bottom, causing a crack in roof of the box. Replace it as the previous repair didnt work.
water finds a way .. and you don't want a 15kg board

Yeah. Big expensive job.....But if it's not leaking and just looks ugly ? Yeah, I know, it will probably fail. Out with the box.

I would probably try to repair from the deck. Open a "window" on deck, scrap foam up to box, repair over with fiber, fill and lam over.

Now that's thinking out of the box! I like.

Proper way is to route it out and replace it. Likely a lot less work that what you are considering and guaranteed success.

I leave to a company who will fix that so I d'ont have a problem and more issues