Repairing a below waterline hole

[Lance Jones]

While installing my Admirals new electric head, I inadvertantly (not that anyone would do so on purpose), drilled through the hull . I have a temporary plug (a dowl) in the hole and will be pulling the boat on Friday to repair. As I can't get to the hole from the inside to back it, what is the best way to repair a 5/16th drill hole in the hull?

[Ron Hill]

Lance : I'd cut the dowel flush with the inside of the hull.  Then take some mat and epoxy over the cut off dowel.

That should hold you till the next haul out, when you can do the same fix on the outside of the hull.

A thought

[Lance Jones]

Thanks Ron; but, I can't get to the inside of the hull. It is in that location where the liner in the head actually joins with the hull.

[Ron Hill]

Lance : You have just installed an additional source of flush water !!!  

I'd consider an early haul and fix it from the outside .  A thought

[Lance Jones]

I'm laughing myself sick!
What would be the best method of repairing the a fore mentioned 5/16th's hole once she's out of the water.

[Ron Hill]

Lance : Once you get out of the water get that area dry. 
Sand down to the hull and fill the hole with an epoxy putty, take some mat and then epoxy the mat on that area.  (I wouldn't worry about the inside)

[patrice]

Sorry about your accident.....
Make sure to make a big chanfer around the hole for a good grip of the repair.

[lazybone]

A NYUK, NYUK moment.

[Lance Jones]

That's for sure!

[Jim Hardesty]

Lance,
Patrice is correct, you should taper out the hole from the outside of the hull.  Then fill with thickened epoxy and patches of fiberglass mat cut to fit the tapered out hole.  "This Old Boat" (book) by Don Casey goes into this in detail.  If you can check it out.
Just my suggestion.
Jim

[2ndwish]

I was concerned about that problem when we replaced our head two years ago. I couldn't find any way to verify the distance from the head platform to the hull. Got enough of a look in there to see that the platform was touching the hull and decided not to drill that fourth hole. The question for Lance: if the hull and platform (liner) do not make a water tight seal between them, won't the leak continue unless the dowel goes all the way to the hull? Conversely, if there is no additional water coming in the dowel must be a pretty secure plug. Most importantly for the rest of us, when you complete the repair, let us know how thick the hull is there- useful information for anyone replacing the head!

[Stu Jackson]

I couldn't find any way to verify the distance from the head platform to the hull.

I used a mirror inside underneath the head sink.  The discussions I've read about head replacements all say be very careful, like, for example, marking or taping your drill bit so it doesn't penetrate too far.

[Lance Jones]

I do have about 6" of dowel sticking outside of the hull. It lined up perfectly with the drill hole from the top. I did have to sharpen the dowel to get it into the hole.. I did have the drill marked for penetration depthe when I drilled. Obviously, it was improperly marked. I know measure twice cut once; but, I thought it was measure once drill once.

[Lance Jones]

She's out on the hard! I had about 4" of dowel sticking out. It was a good, solid seal. The hull appears to be 5/8 - 3/4 inch thick. Ground out around the hole about 2" diameter. Will clean and start filling in when it warms up in the morning.

[patrice]

She's out on the hard! I had about 4" of dowel sticking out. It was a good, solid seal. The hull appears to be 5/8 - 3/4 inch thick. Ground out around the hole about 2" diameter. Will clean and start filling in when it warms up in the morning.

HI,
Lucky you that tomorrow's morning temp might be hot enough.
My next morning that would be hot enough is in about 1,2,3, no, 4 maybe 5 months