Plugging Through Holes

Sep 15, 2009
6,244
S2 9.2a Fairhope Al
I'm looking for suggestions on plugging through holes.
is there threads on the other end if so get a bronze pipe cap and some pipe dope and just cap it off ...since it is out of the water you could also remove the fitting and glass it closed with some cloth and resin
 
Oct 30, 2011
542
klidescope 30t norfolk
Thru holes

One looks like a paddle wheel speed sensor there should be a way to pull the guts of speed sensor up into the boat and usually the manufacture has a plug to put back in hole . My ray marine paddle wheel has died so often I got used to using gps speed but that doesn't give you true water speed. But I found 2 factory plugs on boat and working on modifying one to house a led under water light in it.
 
Jan 19, 2010
12,933
Hobie 16 & Rhodes 22 Skeeter Charleston
Don Casey's boat maintenance bible walks you through the steps of glassing over a hole. I've used it with great success and you get a professional fix.
 
Oct 24, 2010
2,405
Hunter 30 Everett, WA
I had one I needed to remove because it leaked around the flange.
Removing the bronze parts wasn't easy the nut was seized. I used a reciprocating saw by sticking the blade vertically in the hole and cutting through the through hull and the nut in 3 places. Once I could remove the nut, the through hull pounded out. Now it was just a matter of grinding out the hole into a crater and glassing it in. I ended up with about 19 layers of fiberglass and still used thickened epoxy to make it smooth.

Ken
 
Jun 8, 2004
10,536
-na -NA Anywhere USA
Ken;

Most folks would stuff glass and/or epoxy in the hole which is not a very good way. I would have cut out the ragged glass and then bevel the hole at a 45% angle outward or from the inside to the outside getting clean glass. Then on the inside of the hole, I would take a piece of cardboard with two layers of glass with resin on it and resin applied to the inside hold with a string in place, I held that in place until it held which give you a base to work with on the inside. Then I would start laying layers of glass with the first one the size of the hole and each successive layer a little larger to adhere to the beveled edges. If you do not have a resin roller to roll the air out and smooth the wet glass down, you can tip it with a brush dipped in acetone. You will probably have to do this a few times if the glass is on a side and not flat. Once done, spray paint over the glass and sand smooth. where there is paint left, are the valleys and you will either glass or add epoxy. either way, use a fine two part epoxy to fill the small holes with and wet sand. then onto painting with barrier coats and so on.
 
Sep 24, 2013
36
looking looking Corpus Christi
As others have said, your ONLY choice is to remove the thru-hull and fiberglass over it. Look on youtube, there are several videos that apply, nothing real hard about doing it.

Any hole in the hull is a potential leak... think about your boat sinking in the harbor because a thru-hull that has no use has failed while you were gone... A couple hours fiber-glassing, fairing and painting compared to reflating your boat and drying it out... let's not even mention engine damage.

Pull it out, fill it in, paint it up - no other choices need be considered...
 
Jun 16, 2014
18
Catalina 25 Muskegon Michigan
I'm looking for suggestions on plugging through holes.
I removed all my through hulls and glassed over them. The first one was scary pulling it out and seeing that hole in the bottom. After getting over thefirst one the other two went fast and easy. I don't like the idea of holes in the boat. The swing keel cable hole is the only one I have that's below the water line and I still don't like that one.
 
Oct 24, 2010
2,405
Hunter 30 Everett, WA
Thanks Dave

Ken;

Most folks would stuff glass and/or epoxy in the hole which is not a very good way. I would have cut out the ragged glass and then bevel the hole at a 45% angle outward or from the inside to the outside getting clean glass. Then on the inside of the hole, I would take a piece of cardboard with two layers of glass with resin on it and resin applied to the inside hold with a string in place, I held that in place until it held which give you a base to work with on the inside. Then I would start laying layers of glass with the first one the size of the hole and each successive layer a little larger to adhere to the beveled edges. If you do not have a resin roller to roll the air out and smooth the wet glass down, you can tip it with a brush dipped in acetone. You will probably have to do this a few times if the glass is on a side and not flat. Once done, spray paint over the glass and sand smooth. where there is paint left, are the valleys and you will either glass or add epoxy. either way, use a fine two part epoxy to fill the small holes with and wet sand. then onto painting with barrier coats and so on.
Thanks Dave
I hadn't thought of the cardboard. Other that that it's pretty much what I did. I actually did my first layers with really fast cure epoxy (pot life must have been 30 seconds) It did take a while for each successive layer of epoxy glass to harden. I think I beveled my hole greater than 45 however.
Ken
 
Sep 18, 2014
22
Wharram Tiki Belfast ME
It's interesting how the sequence of circles of cloth applied has changed. When I did my first through hull closure about 20 years ago the process recommended was to apply the smallest circle first then next on out to the largest covering the whole shebang.
This always made sense to me since each layer would have a mechanical bond to the hull and chemical bond to each other. I've repaired dozens of holes this way with never a failure, that I'm aware of:)
Now West and others say reverse the process, largest first! Now only the largest has the mechanical bond, admittedly a larger area, but I don't see how this is stronger then the prior sequence.
Has anyone actually done strength tests?? If so could you provide a link to the science, or at least the logic, behind the change. Thanks
 
Jun 16, 2014
18
Catalina 25 Muskegon Michigan
Now West and others say reverse the process, largest first! Now only the largest has the mechanical bond, admittedly a larger area, but I don't see how this is stronger then the prior sequence.
Has anyone actually done strength tests?? If so could you provide a link to the science, or at least the logic, behind the change. Thanks
I read someplace it is stronger because you are trying to press a larger section through the smaller hole but I also read it allows more fibers of the inner most patch to be exposed water. I did mine like you described...smallest to largest... it seemed to lay in better... also I did both sides of course. To get my patches started I made a small 1/8 inch thick epoxy "plug" to fit the hole exactly...I sanded it down to match the hole and tap it into the middle of the beveled hole with a pencil. It was just big enough to hold itself in by friction, epoxied that in and let it dry first. This gave me a good base to start layering the pieces of matt and glass in.
 
Aug 18, 2013
8
Siedelmann S37 Toledo - HVYC
Something stupid simple! Measure the hole, then buy a plug that has a washer an a S/S bolt and a wing nut. Make sure the plug in slightly larger to make sure it is tight after you tighten the wing nut, Walla! Do it from inside or outside. Your welcome!!
 
Sep 18, 2014
22
Wharram Tiki Belfast ME
Something stupid simple! Measure the hole, then buy a plug that has a washer an a S/S bolt and a wing nut. Make sure the plug in slightly larger to make sure it is tight after you tighten the wing nut, Walla! Do it from inside or outside. Your welcome!!
I seriously hope this is an early April Fools Joke.
 
Jun 16, 2014
18
Catalina 25 Muskegon Michigan
Something stupid simple! Measure the hole, then buy a plug that has a washer an a S/S bolt and a wing nut. Make sure the plug in slightly larger to make sure it is tight after you tighten the wing nut, Walla! Do it from inside or outside. Your welcome!!
That would work...as long as the boat is never put in the water
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Something stupid simple! Measure the hole, then buy a plug that has a washer an a S/S bolt and a wing nut. Make sure the plug in slightly larger to make sure it is tight after you tighten the wing nut, Walla! Do it from inside or outside. Your welcome!!
I believe that's a plug for a leak in a water heater tank?
 
Last edited:
Jan 27, 2008
3,092
ODay 35 Beaufort, NC
Power boats use stern plugs all the time that are rubber plugs with threaded rod that causes the rubber to expand in the hole. I don't recommend it for this application as a permanent fix is in order but millions of boats are floating today because an expanding plug is keeping out the ocean.
 

Joe

.
Jun 1, 2004
8,318
Catalina 27 Mission Bay, San Diego
Drain plugs are normally conveniently located and can be readily seen in the normal operation of the vessel, whether it be a sailing dinghy or a ski boat. Thru hulls are often located in less accessible and visible locations....