Repair of rotten sandwich deck

[ulferlingsson]

A serious problem existed with the Ensenada 20 I bought in allegedly "sailable condition": A soft spot on the deck nest to the mast. There was de-lamination on the underside, in the cabin. This fix seems to have done the trick:

1. Drilled small holes on a 1 dm grid.



2. Injected an epoxy that is sold for the purpose. Some holes took nothing, others swallowed many loads of 10 mL each. As epoxy came out from other holes, I sealed them with tape.



3. Press it together (a jack was used to get the pressure). I had to do it in sections since the first epoxy started curing before I was done.



I also drilled a few holes on the outside and managed to get some more epoxy in that way. In total perhaps I injected 4 dL in 0.5 m2 deck. It was enough to make it stiff again, but for good measure I added a layer of fiberglass on the underside. Since the top gelcoat was severely cracked I also brushed crevice-filling epoxy over the deck. Add paint and it looks and feels like new.

[sailingdog]

I can pretty much guarantee that you didn't really fix the problem by doing this... and it will make properly repairing it much more difficult down the road.

[SaltyMonkey]

Absolutely agree w/ sailing dog. To properly repair a problem like this requires cutting off the top layer, cutting out the rotten core, drying it out, filling in with new core (balsa or ply), glassing in with epoxy and mat, fair, paint.

The ejection method sited not only doesn't work effectively, but it was done wrong. Sometimes people do it on the deckside, but it takes a few months for the moisture to evaporate through the holes, and the rot is still in there. Looks like you just locked it in by going underneath. Moreover, it is not evenly spread throughout the voids in either case. The voids will always be there

However, doesn't look like this boat is for a transi, and may sail locally, so you may be fine for your required sailing purpose.

[ulferlingsson]

(smiling)

[tommays]

While i am sure you got epoxy to stick to something like the inner skin its on the unlikely side you got the inner and outer skin to bond to a wet core

I can say for sure it does not scale up to large boats well and if you look at Git Rot Penetrating Epoxy its for dry-rotted wood NOT wet

[LandLocked66c]

I agree with these guys. I'm re-coring my sole currently.

http://www.sailnet.com/forums/gear-m...has-begun.html

[ulferlingsson]

Meanwhile I am walking on my deck. The problem I had was that the deck was too soft; it is no longer too soft; thus the problem is gone. If it again would become too soft, and the same repair does NOT work again, then there would be reason for concern. But that day that worry. Don't invent problems if you don't have to!

[eherlihy]

This is an interesting concept. However, it flies in the face of the experience of many of the members here, and manufacturers recommendations.

See http://www.westsystem.com/ss/assets/...lacingcore.pdf

and this link where the owner documents the established procedure for turning this

into this
then this
this
and eventually this

[ulferlingsson]

I didn't invent the method, I found it on the web, and the product is from West Systems if I'm not mistaken. It is worth noting that it was a local problem on my boat, perhaps related to a too weak deck to begin with; the starboard side is very strong since the galley is there, but the port side has no support at all. My first thought was that it was the sailing forces that had ruined the deck, not rot. And I still haven't seen any evidence to the contrary (I put in in the thread heading since I assumed there might be some degree of rot, too).

[hellosailor]

Well, it is possible that both "sides" are right. Consider a soft deck. it is "soft" because as you put pressure on it, the water and softened core squish over a bit. Now add enough epoxy all around that area, and you have "clamped" all the squishy stuff into one place. Something like slapping plaster around a balloon, now the balloon seems quite solid.

Until the deck core degrades a bit more, or the epoxy lets go a bit and the soft stuff starts squishing around past it again.

If it lasts a year...great, you're sailing. But I wouldn't be surprised if it starts squishing again at some point in the future, and then needs to be recored. Unless you first remove all the moisture--nothing will properly and permanently fix a soft deck core.

If the product is from West Systems, call them. They'll provide free technical support and they'll know exactly what and how it can or can't work on.