Structural damage repair

[SteveG58]

Hi all. Can anyone give me advice on the feasibility of a catamaran hull repair? The damage was caused by grounding. No external damage is visible but internal damage is apparent in that 2 cross members /ribs have been damaged. For that to happen there must have been significant deflection. Would that not also result in delamination over this area? It is a balsa core construction. She was sailed back to home port covering over 200 miles after the grounding without obvious issues.

The rest of the boat is in good condition. Estimated value of the boat is approx $80k.
Many thanks

[CheoyLee39]

I am surprised you have not received a multitude of well informed and other replies yet, lol.....
Mine certainly belongs into the latter I don't have a Catamaran and have not had an issue along these lines. And I was not there at your mishap. However, if you have no hull damage as such and were able to sail happily home then I would suggest you may not have a huge problem long term.
As you mentioned it was a grounding and not a solid sharp impact, hence no external damage.
I am guessing it was a grounding on one side. Catamarans purely through design and build would have reasonable flex. And obviously this is the cause of your internal ribs becoming damaged, although you did not specify the damage.
I would be inclined just to contact someone who has professional knowledge of cats and repair, pay them for a few hours to inspect and advise you without telling them that you may or may not want them to repair. Then make a realistic estimation yourself out of that. If the thing tracked home okay and has no external visible damage you may well be able to repair it yourself .

[barnakiel]

Check for water ingress in the balsa and for de-lamination of the core in the impacted area.

If no water ingress and no de-lamination then it may well be worth it.

b.

[SteveG58]

Thank you for responding. No water ingress. Will check the core delamination. I have spoken to a local builder and it appears quite possible!

[barnakiel]

De-lamination is repairable. Monohulls get flipped upside down by the boatyard then normal skin removal, new core, glue, new skin, etc. The boatyard that fixed Great American III and IV has nice pictures of similar fix on monos.

b.