View Full Version : Help! Underwater hull repair

07-31-2000, 08:49 AM
Trying to find a local yard that has the capability (and time) to haul a 58', 34 ton boat is proving difficult. So she's going to have to sit in the water a little bit longer than desired. In the meantime I need to do something to reduce the onslaught of seawater into the bilges. The secondary sump pumps are keeping up with the demand. But the 3 am nightmares about pump failure are doing me no good! I would like to stabilize her as best as possible for about 6 months. Unfortunately I cannot locate the major source of leakage from inside. Does anyone have any recommendations for 1) locating leakage from the outside and 2) a good but cost-effective way to temporarily stem the tide?

Mark Swiderek
07-31-2000, 09:14 AM
Do you intend to use her? I had a similar problem but I was waiting for my turn to haul. I just went out and bought a 40' X 60' blue tarp and wrapped her hull. Lashed the grommets to the rail. I was going to tack the tarp down by nailing plaster lath to the hull. But I never got to it and the tarp held up fine. It didn't stop the leaks but slowed them enough for me to get some sleep.


Ian McColgin
07-31-2000, 09:17 AM
Use to slow Goblin's leaks by running into the marsh and using the engin to swirl silt. The more organic, less sandy, the better. One old local guy told me that in the days of more farming down here, the marshes frequented by cattle provided the best silt.

Some say sawdust swirled around will work, but that appears not fine enough and you're introducing a new problem into the water.

Find some soft gooey smelly organic ooze, run her gently aground and let the prop raise the silt for a half hour or so.


07-31-2000, 10:09 AM
What about going over the side and smearing Slick Seam in suspected areas?

07-31-2000, 11:12 AM
Sawdust works very well, but if your planning to use the boat it may work its way out. Try some fine and coarse dust. It works very well. I used a bleach bottle cut open nailed to a stick. Filled it with dust,kept it upside down under the boat so as not to lose the dust, then turn it up and let the dust float up past the leak. I have done the slick seam thing too., but in a working plank it compresses and doesn't necessarily return, and the leak returns. I have heard that 5200 works well in tthis situation if you know where the leak is. But then your left dealing with that after, though i have been told that a heat gun loosens 5200. If your leak is structural you can count on it getting worse.

Bruce Hooke
07-31-2000, 01:13 PM
Can you at least narrow down the location of the leak by blocking the limber holes or otherwise temporarily compartmentalizing the bilge? Knowing roughly where the leak is would, I expect, greatly increase the chances of locating it during an underwater inspection.

Ian McColgin
07-31-2000, 01:47 PM
Leaks like that can come most anywhere. Especially if in the garboard seam, they'll be about impossible to spot, especially in water. So go either the muck or sawdust to keep her up for now. Neither, by the way, stays in the seams if you're sailing much. But a good hang-out expedient. Besides, makes you one with Farley Mowatt. Get "The Boat Who Wouldn't Float" and feel good.

07-31-2000, 01:59 PM
Ian - good suggestion! If
The Boat that Wouldn't Float" is as good as "The Dog Who Wouldn't Be" I'll just curl up in the cockpit with a good beer and read and laugh - to heck with the bilges!

I will give the sawdust and muck trick a try. She is not in any condition to sail at this point. And it might give the pet bilge crab something else to eat.

07-31-2000, 03:37 PM
If the sawdust/cowmanure/saltmarsh muck fixes fail (all venerable BTW) you will have to isolate the area more closely. Then a fother (tarp option) or a sheet metal tack on, might be the way to go. 'Course I've heard of a bad stop-water(s) letting in seemingly huge amount of water. It's one of those time equations. Since they tend to be in angular areas the fother might not work.

Can you interest the local troubled youth/sea scouts/mental health/boyscouts/girlscouts/woodenboat/and or sea training program that it would be educational to crawl around in your bilges for a voluteer day? Free lunch?

Don Braymer
07-31-2000, 06:13 PM
Say, been there, done that.

Get a 110 sump pump or pumps with enough capacity to suck her dry and you will probably be able to see little rivulets of water varying to actual small fountains. Measure the locations carefully, count the planks.

Now the leak inside is not necessarily the same place as the leak outside, so;

Now you must verify the leak from the outside. Take cellophane paper outside and work along the suspected area/seams until the cellophane sticks to the boat. Also, you can actually feel a light pinch on your finger tips if you touch a leaking seam.

Now when you have found the leak, dive on the vessel, pound packing strings (carefully!) into the small leaks, and cedar wedges into anything really large. Smear over dolphinite, make a copper plate patch that is quite a bit too big, drill little holes around the edges, smear it with dolphinite as well, afix the plate with 1 inch or so bronze nails.

This makes a really sturdy patch, and you could count on it for at least a year. Your bottom cleaner can tell you if the copper starts to really surrender to electrolysis.


Dale Harvey
07-31-2000, 10:35 PM
If you have good enough visability, the bubbles from your scuba gear will be sucked into the leaks. Also a squirt gun filled with food coloring, but wear no fins, move slowly and work at slack tide. Gardner plastic roof cement, in the wet application version works better than Dolfinite at a fraction of the cost. Roll copper fashing should also be available at a good roofing supply. Apply tarred felt to the copper with hot tar, then butter with Gardner, nail on, and you will have a semi-permanent repair. There were several rails in Tarpon springs, just stay away from the Greeks, unless you speak their language. Unfortunately your vessel is a prime candidate for worms, likely all the local yards already know if this is the case, and are not likely to haul you at all. Gulf Marine Ways in Ft. Meyers Beach might, if you post sufficent bond.

Classic Boatworks - Maine
08-01-2000, 05:23 AM
There should be plenty of yards in your area who will haul a boat of this size. What exactly is the problem with getting her pulled out of the water? Most yards will give priority to a boat with a leakage problem.

08-01-2000, 08:42 AM
try swimming around and under her with a milk carton that you have punched a hole in, the white milk shows up good and as you go over the hull you should see where it gets drawn into the boat.

Oyvind Snibsoer
08-01-2000, 09:12 AM
The ant huggers out there may not like this, but...

The tradtitional way to temporarily fix leaks in the days of the sailing ships was to throw ant's nests in the water. Actually called "mauring" from Norw. "maur" = ant. This is the kind of nest that's made from pine needles and forms a mound in the forest.

Bruce Hooke
08-01-2000, 10:20 AM
"The Boat that Wouldn't Float" should be required reading for anyone involved with an old wooden boat, if for no other reason than that it reminds you how much worse things could be. "The Dog Who Wouldn't Be" sets an awfully high standard but "The Boat that Wouldn't Float" is nearly as good (IMHO).

- Bruce

Terry Etapa
08-13-2003, 01:53 PM
I'm having the "Boat That Wouldn't Float" problem. After a 4 day weekend in Washington's San Juan Islands, a seam opened up a wee bit. Now, my bilge pump runs about every 15 - 20 minutes for about 10 seconds.

Here's my dilemma. It's a work boat with iron boat nails, and hot dip galvanized screws. I don't want to put any copper near my nails for fear of galvanic effects. Am I just worrying about nothing?

If not, what about using Henry's Yellow Glass Reinforcing Fabric (http://www.henry.com/datasheets/Henry_183_TDS.pdf) instead of copper? Will it stay on without nails?

Alan D. Hyde
08-13-2003, 02:47 PM
I've seen lobstermen use Lexan sheets with 5200 smeared on them, along with a handful of roofing nails... :D