Hull Repair

[Cal]

My DS2 sat on its anchor at low tide and got a three inch cut port midships, below the water line. Ground back the cut and found the fiberglass fractured. I can't reach this from inside the hull and there is open space behind the hole.

I am thinking straight West epoxy and layered fiberglass patches, is there a better way? Should I spray some door/window expanding foam inside to provide backing?

Thanks,
Cal

[GreenLake]

Cal,

grind back to where the fiberglass isn't fractured (if you haven't done so already) and leave the edges with a very shallow bevel - one in twelve.

I would lay up a rectangle of laminate on a workbench (on top of plastic or wax paper). Once that's cured enough to be stiff you can shove that through the cut and glue it with epoxy from the inside.

You do need to sand the inside edges to roughen them (and degrease them) and you might want to drill a hole into your sheet and put a cord or wire through, so that you can pull it tight against the hull while the glue cures.

You now have a shallow "hole" that's closed on the back side with a thin layer of laminate. Cut the cord or wire and simply laminate patches of glass and mat (in decreasing size) until you've nearly filled the hole.

Use some epoxy filler to level the surface, sand and paint.

Here are some pictures from a repair I did along these lines, the only difference was that I could apply the patch from the inside, so I could make it larger than what I would have been able to shove through the crack.

First picture: patch. Second picture: getting ready to glue. Third picture: patch glued in (top), after I added one layer of mat (bottom).

[thumb=1037][thumb=1038][thumb=1041]

There's not picture of the completed repair - it's undetectable.

I would not use expanding foam.

I used SystemThree epoxies which are blush free, with others you may need to wash off the blush from the patch before adding laminate.

I used the epoxy glue in the cartridge (middle picture) but you can simply use the same laminating epoxy.

[PassingWind]

I used this method on my ds1.

Worked like a charm. I had a crack where the seat is and didnt want to cut an second access panel(have one at the front but to far from the crack)

http://www.youtube.com/watch?v=V6Enxtqw ... ata_player

[Cal]

Thank you both. Clearing the fractured fiberglass has enlarged the horizontal hole to 1/2" x 2" plus beveled edges. Would you make the opening larger to reach inside to sand or just use layered patches on the outside?

I did find foam about 3/4" in from the hull so it would be a small area to add expanding spray foam.

Cal

[PassingWind]

I didn't sand inside. The intent of that backing piece isn't permanent. Just needs to stay long enough for the glass layers to dry. After the resin dried the backing was glued in place pretty well without sanding the interior.

I wouldn't use the spray foam as its not closed cell and will soak up water. That stuff could swell up and push out the fracture to much as well

[GreenLake]

Cal,

what Scott said. You could make your hole larger, but why? Even so, 1/2 " should be wide enough to reach in and degrease the backside of the edges with some IsoPropyl.

The little backing plate can be rather small, 2" x 4" would seem plenty. And you don't need to laminate as many layers as I did, perhaps even only mat + cloth. In fact, some flexibility in the patch will help it conform to the hull curvature.

Just make sure you really did get all the bad laminate out...

Good luck!

[Cal]

I read the West fiberglass boat repair and page 22 talked about a small hole, less than 8" on any side, being repaired from the outside.
http://www.westsystem.com/ss/assets/How ... enance.pdf

So I did that after using acetone to clean the area. After cutting my patches I had a lot of little scraps and cut them up and put them in the mix after wetting the patches. This gave me an angel hair pasta mix that I stuffed inside the hole, so I at least have a mushroom like plug.

My mistake was using a black piece of plastic to wet and hold the patches. Use clear plastic to better align the patch to the area to be patched, I have some sanding and filling to do.

Now to roll the hull more and work on cracks at the CB well.

Thanks for all the help.

Cal

[GreenLake]

I'm sure you are fine, your hole is rather small, but some of the "generic" documents are designed for "generic" boats, including all of them larger than 17' and which have more substantial laminate schedules.

8" is about as much as you can "bridge" with laminate, that seems to be the motivation for that number. When I did my repair, the hole was narrow (but 9" long). The biggest problem, now that I think back about it, was that it appeared as if the two sides didn't actually line up.

Using a patch was intended to remedy that - but also, if a 9' boat could knock that much of a hole in the hull I felt that just a bit of reinforcement (especially on the receiving side for a failed starboard-port crossing) couldn't hurt.

So I was happy with some definite over-engineering there, but in return, that left me greater flexibility with using Quick Fair in building up to the hull lines, as I didn't need the material in the hole itself that much for strength.

But, as I said, you'll be fine and I'm glad you got your repair taken care of without losing more time on the water.

[Cal]

I am caught in the 'while I am at it' trap and tired of all the water it picks up on the mooring - between the hull and the liner. PO put some flexible caulk on the hull cracks, I will try some dremel work and an epoxy paste - then into the water.

I think I used five or six patches, definite overkill. Already sanded and waiting for the final application.

Thanks again for the support.

Cal