Plugging a Hole in the Hull

[Fotoman]

The yard where I bought my boat had drilled a hole (diameter: about 3/8 of an inch) in the hull to drain the bilge. Not sure how brilliant this technique is but I have to plug it before launching the boat.

What is the proper way to do it?

I was thinking of filling the hole with 3M 5200, inserting a self-tapering bolt or screw in the hole, putting a few coats of Interprotect 2000 on the bolt head and finishing it with some Interlux Watertight epoxy Filler for fairing (see drawing below).

Any inputs?

[Waterborn]

If you are going to use epoxy to seal the screw, then I would just eliminate the screw, since it would be hard to remove it again. I would used thickned epoxy, and then two layers of 6 oz fg cloth.
If time is an issue (ie: short boating season) Your idea should work fine.
Good Luck

[Fotoman]

Thanks Waterborn. The idea is that it wont be removable and I also want to avoid doing any fiberglassing. I need a quick and simple solution.

[gonesail]

if you can reach it from inside .. put some tape on the bottom of the hole and fill it with thickened epoxy.

[Cheechako]

How about running a 7/16 tap in the hole for threads and putting a bronze bolt in there. Might want to drain it again! Nothing wrong with a drain in the bottom of the boat.

[Fotoman]

Originally Posted by gonesail

if you can reach it from inside .. put some tape on the bottom of the hole and fill it with thickened epoxy.

That's part of the problem, I can't reach it from the inside. There's like a double floor.

[Fotoman]

Any more input on this?

[bwalsh]

Where is the hole located, on a big flat section? On a contour? You can always add a bronze garboard plug for future draining (from the outside) the flat keyed tool type fair that in so it isnt an obstruction. Ive done and seen this done on many downeast boats... I just hate to see you fill a hole then make it again for draining since the hole has already been made. If you dont like the leave a drain ideas above, Id agree to use some thickened epoxy in the hole then grind back in a 3 or 4 to one ratio and get a couple quick layers of glass in there. West system recommends you grind back more but its baloney in that size hole. Your idea looks like its time consuming with the 5200 extended drying time and the epoxy idea is quick and a better bond that it is on the molecular level. Some sanding involved anyway you cut it. Good luck.

[maxingout]

Originally Posted by Fotoman

Thanks Waterborn. The idea is that it wont be removable and I also want to avoid doing any fiberglassing. I need a quick and simple solution.

I once had a small hole punched in my hull the day I was going to launch it. I ground it back, filled it with epoxy, applied a couple of fiberglass round patches to the ground out area. Within twelve hours, I sanded the patch smooth and I applied the bottom paint. The boat went in the water the next day.

A proper repair doesn't take long, and isn't very much work.

[s/v Jedi]

Originally Posted by maxingout

A proper repair doesn't take long, and isn't very much work.

I agree fully. All that talk about screws with 5200 or permanent plugs in the hull for draining make me feel sick.

A standard epoxy & glass repair is best and quickest way to go. Grind the hole out from the outside (like with a dremel & drum sander bit) so that the epoxy & glass "plug" becomes tapered.

cheers,
Nick.

[daedaluscan]

I am sure that you will doubt me but a whittled wooden plug cut flush would be fine. I will expand and stay in place. If you have doubts smear with 5200. You could drill it out next year.

[roverhi]

Holes in the bilge are quite common in areas where boats are hauled for the winter. Deck leaks, lost hatches, etc can really create a mess if there is no way to drain the water, btdt. I'd just use a flat head screw with LifeCaulk. Carefully do the counter sink so the head is just flush, fill any irregularity in with LifeCaulk, bottom paint over it and Bob's your uncle. Hey, isn't that what you intended to do in the first place just leaving off the epoxy filler.

Aloha
Peter O.
Pearson 35

[Fotoman]

Thanks a lot! Many solutions to this problem.

[GordMay]

Fotoman:

I think that you specified two slightly opposing (mutually exclusive) requirements:
Post #1 - “... the proper way to do it”
Post #3 - “... quick and simple solution”
I hope you se the dilemma posed when one wants to repair fibreglass, whilst also wishing to “... avoid doing any fiberglassing”.

I would second the advice to grind out a taper & epoxy. Forget the screw/bolt.

[Cheechako]

Bronze machine screw, Tapped threads, 3m 101 sealant. It really aint a big deal. If the screw worries you, you'd better remove all your through hulls and glass them up 'fer sure!