I was scraping and chipping rust in an area not checked before, under the shower in the aft head when I hammered my chisel through the hull. I was preparing the hull interior for paint, and I suddenly had a fountain of water. This page describes how I dealt with it, making a permanent repair without hauling the boat out of the water.

These pictures are mostly in chronological order.

  Overview

I was was removing rust in the bilge area of the rear head of the boat, a place that also by poor design got wet every time somebody took a shower.  The rust was extremely thick and if I had found this area when I had the boat out of the water I would have replaced the steel by welding in a new panel.  All of the sudden I had a fountain of water rushing into the boat.  Not a huge problem, but something that gets immediate attention.  I got it slowed by pounding in a wood plug, that took a while because it was in a very inaccessible place, the reason I hadn't found it in the first place.  I then rigged up a 120 volt bilge pump.  Next work on the plug and get the flow almost stopped.  For the next day I worked on ideas to make a permanent patch.  I ended up with a bucket with a closed cell foam gasket that water pressure pushed up against the outside of the hull, this allowed me to remove the plug and work on the hole from the inside with air on both sides.  I sealed perfectly, not even a couple ounces in a week.  The real neat thing is the foam just barely floated the bucket in the water, that held the bucket in place until you got the plug removed and water pressure push it hard against the hull.  At first I tried a rubber horse bucket, it worked for 20 seconds and then leaked worse and worse, the water pressure slowly crushed the bucket and deformed it.  When I changed to a plastic 5 gal pail, no problems.  I thought the rubber night conform to the slight curvature of the hull better.  The foam and 5 gal pail worked great.  I then took some time off and worked on other projects to have time to consider different approaches to make a permanent patch.  There was another rusty spot close to the first that also need attention, just far enough away that it wasn't covered by the bucket, so I was thinking about it in the solution too.

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My brother told me that it's common for steel ships to carry a 22 cal nailgun to shoot through a repair plate and the hull to attach a temporary repair to the hull.  I wonder if that would be considered a weapon or just a repair tool?  Might have to think about this as a dual purpose tool.

For a quick stoppage of the flow, a piece of the flat sheet of closed cell foam on the outside worked real well, it floated up against the hull and sealed pretty well.  It wouldn't allow fixing like I'm doing here though.  The closed cell foam I'm using is cut out of floor squares for a childrens play room. 

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Fountain of water, soon after the damage, I had rushed to find the wood plugs, pounded one in, got the flow stopped, rigged up a big bilge pump, then had time to sit and think. I then got camera, removed the plug and shot the picture. The damage is at a depth of about 2 feet.

This was the first test of an Idea to allow working on a the hole with inside and outside dry while still in the water. This worked for about 30 seconds and the the water pressure slowly crushed the flexible bucket and ruined the seal. It showed the idea had promise.

Almost ready for epoxy, basically I wanted to show that after surveying the situation I ended up with 2 holes close together, I am using two 5 gallon buckets here.

This is the big bucket test 3 that failed due to duct tape not sticking well to plywood. It is made from part of a plastic 55 gal drum. Also shown, the small bucket that succesfully sealed perfectly, and is the type used in the previous picture. The closed cell foam is duct taped to the bucket around the outside of the rim. The big diameter one with the groves cut into the 1/2 inch plywood to allow it to bend to form to the slight curvature of the hull (orientation of the groves is then important ) could be sealed with a plastic garbage bag duct taped on the outside and work just fine. The plywood is also reinforced with a 2x4 that catches a lip of the drum top. It's important for the water force on the bottom of the bucket to be transfered to the sealing ring of foam for this whole idea to work.

How to push a rope against a flow of water out through the hole. Make at least half the rope rigid with a tube outside it. The idea was to get the bucket in place and not even have to go swimming. This might be a good idea for a solo sailer at sea, never leave the boat. Attach the bucket over the side rail to the rope with a weight inside it to hold it upright, the rope connected to the center inside of the bucket, sink the bucket and pull it right up to the hole and let it seal. It didn't work but I think it could with the new bucket, I was using the flexible bucket when I tried this. The end of the rope was then screwwed to the outside end of the wood plug, inserted in the hole and the the hole plugged again, leaving the rope hanging outside the hull where it could be grabbed with the boat hook. This worked great. Floating rope would make this even easier..

The first hole ready for the repair. The next time the boat is out of the water this whole area will be replaced with a new piece of steel, but I expect this repair should last the life of the boat if desired. The plywood is a safety plug inserted and pulled into place outside, to roughly seal the hull if the bucket failed while not working on the hole. These two holes can easily overwhelm the rather large120 volt automatic sump pump and sink the boat. The hole needs to be made oval to be able to use this idea. I guess the diagonal on a square would also work, round won't. You can see the white bucket outside through the hole. - - - - - - - - - - - - - - Over 100 pounds of water force holds the bucket in place, and also bows the bottom of it, Thus the need for the temporary plywood pieces. The plastic bucket would probably not survive this at a 4 foot depth. It could be used if strenghtened inside with plywood rings and bottom.

The repair plates, the corners have been rounded and the nuts welded. There are two tabs that can be bent over later and welded. I also drilled a couple holes in these tabs to allow a wire to be used to pull the plate up tight to the hull when heating the hull to melt the hot melt, before pulling it up tighter with the bolts. Hot melt is very tough and flexible. I've repaired a 1/2 inch wide by 10 in long cut on my dingy and it's survived a rather rough life so far. I will replace the dingy patch with fiberglass when I get to it, but it could easily be a permanent repair. I learned that the hole in the temporary plywood piece in the previous picture, if placed toward one end makes it much easier to remove. It automatically tilts to be pulled right out. When centered it was tough to get it to tilt and rotate to line up with the hole.

The plates ready to install, They have been painted with two coats of epoxy, two coats of hard bottom paint and twe coats of ablative bottom paint. Then a bead of hot melt glue was applied. I've learned that the trick to making hot melt stick extremely well to anything, is to heat the surface of the material up to the melting temperature of the glue. Then it is almost impossible to remove. The glue at this point is well connected to the repair plate, when installed I will heat the hull and then pull the plate into position squeezing the glue out to glue it in place and seal the joint.

One of the plates installed and sealed ready for water. I'll now go back to scraping rust and preparing to paint this area, The bolts and plates were installed and pulled down, then removed to allow painting. They will be replaced and painted. I'm not sure if I'll weld the tabs or not. Probably not, This is all an expirement, we'll see if it is needed, I suspect not, but they are there if it later proves it is needed. Next time I have the boat hauled I'll replace the whole area with a properly welded steel plate anyway. I'll probably get rid of over half the through hulls too. In my oppinion these are just too many holes in the boat waiting for trouble.

The finished repair, I'm having trouble uploading this picture, tried numerous times, same result, I'll try later

I've tried epoxy as glue and next time will probably try gorilla glue, it cures with water contact. I need to test it with salt water.

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