Injectable delamination repair.....

Oscar · Post by **Oscar** » Thu Mar 19, 2009 7:39 am

I know this horse is beyond dead, and I apologize for bringing it up....

BUT, somewhere I remember reading about this procedure/product and I either didn't bookmark or can't find the bookmark.... :-(

It was a product specifically designed to inject into areas of delamination. It drew out moisture and created a new bond between fiberglass and balsa.

I have 25 foot trimaran that has various areas of thin laminate. Specifically the floats/ama's have had water in them too long (PO had it on a mooring). Problem is I can't get to the inside, and if I remove the outside skin I may loose the shape of the hull. (Some sections are 5 foot long.)

Anyone? Thanks.

Case · Post by **Case** » Thu Mar 19, 2009 9:52 am

You're probably thinking of various epoxies. Straight epoxy is used. There are also special "Rot Fix" epoxies. Lots out there, several brands are available. The most popular is "Rot Fix" made by System Three.

You comment on "this horse is beyond dead" is... apt. Injecting will not work if the balsa underneath is compromised. It actually makes repair work harder in the future - you gotta deal with epoxy when removing rotten balsa wood.

Suck it up and cut away the skins, replace the balsa, reglass. Honestly, if the boat may not handle this, it may not handle sailing in the first place! So, I am doubtful the boat is ready to blow up the instant the laminates are cut...

Pictures could help.

- Case

Oscar · Post by **Oscar** » Tue Mar 24, 2009 12:22 am

Ah yes....visuals....

About 20% sounds "soft".....the rest sounds hard.

Post by **Tim** » Tue Mar 24, 2009 6:18 am

If that core sample is indicative of even 20% of the entire area of your amas, then it seems you might have a far more serious problem than can be addressed with epoxy injection. But one core sample doesn't tell the whole story, necessarily. Still, at a minimum, the area you've shown requires a more significant repair than epoxy injection.

Do the scribbles on the hull in your photo indicate the approximate extent of the damage surrounding the pictured core sample, at least that you've been able to so far determine?

Epoxy injection is for filling small voids that form when skins separate (debond) from core within. For this purpose, it works well, as long as the voids are relatively small and not too numerous.

But the core sample you're showing indicates wet, black, rotten core--never a situation where epoxy injection is appropriate. So if this is what the bad areas are like, I'd suggest you need to consider "real" repairs involving opening the skin to expose and replace the core.

It's clear you can't get to the areas from the inside, leaving you with no valid option but to repair from the outside. It is possible to do these repairs effectively and maintain the hull shape when all is said and done, but depending on the scope it can get rather involved. It's probably not a repair for everyone to undertake. I don't know your background, skills, or inclination, so can't comment on whether or how you should proceed at this time.

Oscar · Post by **Oscar** » Tue Mar 24, 2009 9:37 am

Do the scribbles on the hull in your photo indicate the approximate extent of the damage surrounding the pictured core sample, at least that you've been able to so far determine?

Yes, and there's a few more area's like that.

After further research and input from people like yourself I am now indeed convinced that injections are out.

It's clear you can't get to the areas from the inside, leaving you with no valid option but to repair from the outside.

Actually, I can get to the inside. I will remove cutouts of the deck and glass those back in later, in fact building up the deck with a few extra layers.

This is how I will proceed. I will post pictures of the progress.

Quetzalsailor · Post by **Quetzalsailor** » Wed Mar 25, 2009 9:33 am

Are the two amas identical? Are the hulls identical and the decks opposite hand?

This is not a very big boat, nor is it a 'class' boat; You do not have to repair it to meet some class' rules for shape. I wonder whether 'simply' building new hulls would be easier and likely to be better in the long run. Cast new amas off of the better of the two, if they're identical.

As for maintaining shape: You can block the hull in shape with temporary support, frames, stringers. You can work relatively small areas, presuming that there are any. You can temporarily 'tag' the inner and outer shells together, to maintain shape, with gobs of filled epoxy installed through more of the core-drilled holes.

My old 1968 Newport Flying Dutchman was terminally plagued with dusting, deteriorating urethane core between relatively light 'glass lamina. I got a few more years of putzing around time out of the hull by grinding the face and the foam off of delaminated places and laying in solid glass.

Oscar · Post by **Oscar** » Fri Mar 27, 2009 9:53 pm

They are identical... the only difference between port and starboard is that the hardware is mounted on the outside rail of both.

Yes, I have thought about using them as a "plug mould".... been dreaming about carbon fiber. It is a class boat, but the only one in it's class around here. Would never sail a class event..... But there is that minor issue of budget...time as well as money. Maybe down the road.

As the boat will be dry sailed and stored under a hard roof I think I can get many more years out of them with some minor work now. They will be properly dried on the inside between sails.

Meanwhile I have finally removed all the bottom paint....what a pain. Now working on getting the paint off the topsides. And, rolled them outside to bake in the sun.....free heat. They are drying fast.

Removed the beam hinges, all the hardware on the first one. Then cut two plugs out of the deck for airflow and access. The round port will be replaced by a rectangular hatch, that hole has been cut as well. (Not shown yet on this picture.) I can now get to every inch of the inside....
The inside layer is porous. The balsa is only 1/8" It should dry fairly quickly. Where it has delaminated I can probably remove the inside layer with a pair of scissors to scoop out and replace the bad balsa.... Some of the other hollow ringing spots are still tight. Drying and rolling on CPES then sealing with epoxy on the inside should get me back in shape in those spots.