Repairing double planked hull

[rick althen]

Dear Forum

My son recently acquired a older Owens Express Cruiser with a double planked hull. Two of the planks above the water line have holes through both layers of planking. Can someone suggest a quick temporary repair method without removing the interior to get to the inner planks? TIA

Rick

[Foster Price]

Hello Rick

What size are the holes?

If they are up to about 1 1/2 inches then a "dutchman" plug or patch would be fine, I'd epoxy it in. If its anywhere below or close to the waterline in a sailboat then an "bigger than the hole" butt block on the inside might also be called for. I have fixed many small holes like this in my own boat. As long as the holes are not 'structural" sized then repair it like a single skin.

If they are bigger then maybe a more advanced technique is called for.

Cheers -Foster

[rick althen]

Thanks Foster. The plug should work for the smaller of the two holes, about 2 by 4 inches. The second hole is about 8 inches long by 3 inches ans the wood at one end of the hole feels soft. Are the advanced fixes anything I can handle? TIA

Rick

[Foster Price]

Hi Rick

I'm a bit surprised no one else has chipped in on this one.

There was good article on repair of double skins (glued type as I recall but the principles are the same with riveted skins)in WB a few years ago. A search of the archive will turn it up I'm sure.

From memory, Ruel Parker has section in his "Cold Moulded Boatbuilding" book on repair of glued multiskin construction.

These repairs are very simple as long as you can lay your hands on some wood of the same thickness (don't get to concerned at the type, plywood is fine as long as the boat is not a gold plater finished bright or something), some epoxy abnd ss or bronze screws.

Cut away all the soft wood in the inner and outer layers, then open up the outer layer to give an overlap, eg, you original hole is 8x3, once the soft stuff is gone its 9x4, now open up the outer hole to 11x6. If you want to get fancy you can then scarf the edges of the holes. Unless it in a stuctural area, eg right at the chine, or around chain plates I wouldn't bother to scarf.

Cut patches that fit each hole. Cut a third patch that is just able to be passed through the inner hole, this forms a sort of inner butt block. Then glue and screw each patch on, working inner to outer. I'd remove the screws from the outer patch when finished and fill the holes with thickened epoxy.

Rivets work the same but you have to be able to get at the inside to put the rove on and form the rivet head. Generally if it wasn't to "structural" I'd use screws in preference to rivets.

Cheers - Foster

[brian.cunningham]

If it's through both layers anyways why not repair it from the outside, and spare the interior?

[rick althen]

Brian,

That is what I am trying to accomplish a repair from the outside. Any ideas you have yould be appreciated. Foster thanks for your help. The response was very helpful and I will check the archives for the articles you mentioned. Thanks again.

Rick

[On Vacation]

If your hole is big enough, place little pieces of plywood in behind the edges of the hole and screw with sheetrock screws with glue for now. Then take a grinder and oversize the outer layer of the hull in a round fashion. Use a four inche style grinder to od this if you have one. Then cut a rough cut piece the same thickness to fit for the inner hole and glue in place.

then cut a piece for the oversize hole that you have ground down for the outer layer. take you just a piece of notebook paper and overlay the hole and trace the outline and scissors it and then place it on a piece you are going to use. It doesn't have to be the same thickness as let it be rough and then glue in place. Let dry and sand to fit.

I take it they are small ones.