Plugging a hole

inthesprings · #1 (**permalink**) 12-31-2009

Firstly, HAPPY NEW YEAR! and I hope everyone has a wonderful 2010 sailing season.

And on to the quesiton...how do I plug up the small (maybe dime sized) hole in my stern? It was for a fish finder I think. It's usually above the water line unless the boat is sailing hard on a port tack or in a following sea, in which case, well, I'm taking on water. Surprisingly (or maybe not) it took me awhile to figure out where the heck the water was getting in from, even though there's a hole in the stern (duh!). I think it was the little cover over the hole that threw me. Anyway, I got the Don Casey Sailboat Maintenance book for christmas which it seems would have me grinding a big beveled (12:1) depression around the hole and laying it up with epoxy and cloth. Can't to that from inside the hull because it's in a really tight spot, and I'm not into grinding up the hull on the outside and having to repair the gelcoat.

Can I just plug the thing with thickend epoxy or even marine tex (which is just thickened epoxy, isn't it)?

FWIW, the hull is solid fiberglass and 1/4 to 3/8" thick in this area.

Thanks!

-Shawn

canadianseamonkey · #2 (**permalink**) 12-31-2009

Myself, I would try the thickened epoxy first. I would even apply a second coat to make sure you've covered it completely. It should hold up fine and if it doesn't, then you have to go to plan B.

dantaden · #3 (**permalink**) 12-31-2009

Follow this weblink to West System where you can download the instruction manual to prep, fill and finish your holed area, + other stuff you may want to fix on-board.

Have fun and a great new year.

WEST SYSTEM | Use Guides

CalebD · #4 (**permalink**) 12-31-2009

Shawn,
One thing about gel-coat is that it is a polyester resin as opposed to an epoxy resin. You can apply epoxies over polyester surfaces but the reverse is not recommended. Check any can of gel-coats fine print to verify this. Epoxy has better adhesive qualities then polyester resins and therefore is the glue of choice for many repairs. Epoxy may adhere better but it does not hold up to UV as well as pigmented polyester resin (gel-coat).
So you could do your 12:1 bevel and fill it with polyester resin and cloth and then gel coat it, or your could fill it with thickened epoxy and simply paint it. Since we are talking about a dime sized hole the easiest thing to try first would the Marine-Tex (thickened, pigmented epoxy paste). If your hull is white then use the white Marine-Tex and it will look very similar to gel coat. For a larger, more invasive repair I would go by the book.
Happy New Years.

inthesprings · #5 (**permalink**) 12-31-2009

Right, well thats good enough for me. I will try the Marine tex then....when it warms up a bit. Thanks.

orientalnc2010 · #6 (**permalink**) 12-31-2009

Hi Shawn,
A simple fix might be to plug the hole with a stainless steel bolt, round head of the appropriate size with lots of sealant and use the clam shell to conceal it.

leland515 · #7 (**permalink**) 01-04-2010

Quote:

Originally Posted by inthesprings

Firstly, HAPPY NEW YEAR! and I hope everyone has a wonderful 2010 sailing season.

And on to the quesiton...how do I plug up the small (maybe dime sized) hole in my stern? It was for a fish finder I think. It's usually above the water line unless the boat is sailing hard on a port tack or in a following sea, in which case, well, I'm taking on water. Surprisingly (or maybe not) it took me awhile to figure out where the heck the water was getting in from, even though there's a hole in the stern (duh!). I think it was the little cover over the hole that threw me. Anyway, I got the Don Casey Sailboat Maintenance book for christmas which it seems would have me grinding a big beveled (12:1) depression around the hole and laying it up with epoxy and cloth. Can't to that from inside the hull because it's in a really tight spot, and I'm not into grinding up the hull on the outside and having to repair the gelcoat.

Can I just plug the thing with thickend epoxy or even marine tex (which is just thickened epoxy, isn't it)?

FWIW, the hull is solid fiberglass and 1/4 to 3/8" thick in this area.

Thanks!

-Shawn

Sand/Grind it all out until you have bare fiberglass, mix up some Marinetex, and stuff it in there

It's not a load bearing area, and it's very tiny.
You'll be fine

leland515 · #8 (**permalink**) 01-04-2010

Quote:

Originally Posted by orientalnc2010

Hi Shawn,
A simple fix might be to plug the hole with a stainless steel bolt, round head of the appropriate size with lots of sealant and use the clam shell to conceal it.

Wow, would have never thought of that!

bychance · #9 (**permalink**) 01-17-2010

I used simple mix in tube, underwater epoxy for a hole in bottom of my 24 hunter. Had the boat for several years, and never leaked//

hellosailor · #10 (**permalink**) 01-18-2010

Or, you buy a short fat stainless carriage bolt, put some sealant under the head, and bolt it through the hole. That avoids the need to repaint the transom or otherwise blend the repair in. Add some Loctite or use two bolts, or at least a star washer, to make sure the nut inside doesn't work loose.