13-footer, Rotten Wood

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Posts: 18
Joined: Sun Jul 09, 2017 2:07 am

13-footer, Rotten Wood

Postby jeopardy954 » Sun Aug 20, 2017 2:23 pm

I started the disassembly of my 1979 SPORT 13 for a refresh of the boat. I was planning on doing interior paint and mahogany refinishing or replacement, as needed. I started by unscrewing and removing the mahogany, and, to my great chagrin, as I pulled out the screws from the gunwales they came out with some nasty brown slurry of rotten wood. The same held true for the floor panel where the console mounts.

I started probing with a metal probe and found I could push as deep as I could reach and pull out as much brown mush as I could grab.

To make matters even worse, I pulled out the bottom thru-hull, and got a nasty coffee-ground slurry from around the thru-hull. I could push my probe into the bottom portion of the transom as well.

So, needless to say, I'm at a loss for what to do next.

Does this mean that the rot extends through the whole slab of wood?

I take it this is some sort of plywood--which I know rots quickly once part of it is breached. Does my boat's rot extend all the way up to the transom?

Have others dealt with this problem with their restoration?

I know replacing the wood would exponentially increase the time and difficulty of what I thought was going to be a simple project. I don't, however, just want to screw my interior back into what I know is rotten wood.

To those with experience with rotten wood in their hulls: how did you address it?

I'm at the point right now where I'm regretting buying a Boston Whaler because of how much a task it is to replace the wood in it versus a conventional fiberglass boat.

Posts: 8774
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula

Re: 13-footer, Rotten Wood

Postby jimh » Sun Aug 20, 2017 7:10 pm

I think you are describing a decay or rotting of the embedded wood reinforcements inside the hull which serve as the material for screw fasteners to hold to for attachment of the console and seat risers. I suspect the boat was previously used in freshwater, which will be more likely to cause wood to rot than saltwater.

The remedy for the soft embedded wood is probably--I have to say probably because I have not tried this myself--to apply some sort of chemical treatment to stop the rot. And to let the boat dry out. Put the whole boat into an environment like the desert--warm and very dry--and let it dry out for a year. Once you feel as though the boat has dried out and the rotting process has halted, I would reinforce the mounting points by cleaning out the area under the fiberglass in the fastener holes and removing the soft wood. One tool for doing this is a small Allen wrench or any sort of hard steel L-shaped item. Push the short leg of the L-shaped Allen wrench into the fastener hole, then chuck the long part into a drill. Rotate the Allen wrench and use it like an auger to clear out an area under the fiberglass around the mounting hole. Use a strong vacuum to pull out the chips and debris.

After making this circular cavity around the hole, you will fill the void with a mixture of epoxy resin and high-density filler. Let the epoxy cure. Now you have a hardpoint under the fiberglass that you can drill into and use to retain a fastener.

There are not that many fastener holes to rebuild, so it won't be an enormous project.

If you are talking about the actual wooden components all being rotten, then just keep them for use as patterns and cut new components from fresh mahogany plywood or planks, as appropriate.

Or, sell this boat for cheap money and buy one that need less work.