When to Patch when to replace

[mplangley]

My fairly recently acquired 1972 grand banks 32 has some rot in the fabled areas on the port side. I think this must have been the weather side or something because the starbord is very good by comparison.

The rot is on a portion of the flybridge where the seats meet the flybridge wall. This is about a 1X1 foot area with a few smaller areas along they bottom seal of the flybridge wall.

The other area that is rotting is about a 1X2 foot aread under the window.

I am tempted just to scarf cut the sections out and scarf in some plywood and be done with it. It may be a bit ugly from the inside but the window section would be hidden behind the cabin settee anyway unless the top bunk was latched into place.

So the question is - with rot. When is it ok just to patch and when do I just need to bite the bullet and replace the entire side of both the cabin and the flybridge. It seems a shame to have to go through so much work for the sake of these small areas.

thanks

 

[Bob Cofer]

If you scarf the patches in and lap the joints it usually works quite well. I seal the edges of the joints with epoxy prior to installation.

Or remove the flybridge completely like we did! Take a look at the Transformation Continues thread and you will see what we have been doing.

 

[mplangley]

If you scarf the patches in and lap the joints it usually works quite well. I seal the edges of the joints with epoxy prior to installation.

Or remove the flybridge completely like we did! Take a look at the Transformation Continues thread and you will see what we have been doing.

Thanks Bob. I have been admiring your beautiful boat on the Transformation Continues and other threads. By the way Im wondering about your color scheme. I really like the gunwale color.

As for "scarfing" in plywood - do you have any recommendations as to technique. I was planning on just trying to be as precise as possible and attempt to make a real scarf joint in place. I have done it in the shop but never on a vertical surface like the pilot house.

Also do you have a thread showing how you did the flybridge rebuild?

 

[DHeckrotte]

Not highly stressed areas? Paint finish? You could probably do with butt joints. You could reinforce the joints with either dowels or laid-in scraps of wood. You could use back-up blocks, and regain all the strength. Of course, epoxied with structural fillers, epoxy-coated end grain. Since doweling accurately would be an exercise in blue-tinged frustration, drill oversized holes and set the dowels in filled epoxy.

Scarpfs could be cut with a chisel and/or plane. A rabbet plane would be particularly handy since it would enable you to get to the edge/corner. You'd have to back-up the feather edge of the scarpf, on both the boat and the patch, with a temporary block while planing to keep it from collapsing.

With room to work, you could make up a jig to guide a router along the intended incline of the scarph. Additionally, West System's Gougeon brothers would be happy to sell you, or tell you how to make, a setup for cutting scarphs using a circular saw.

I restyled part of the interior of our previously-owned '72 Morgan 27 sailboat. The place was Teak-flavored-Melamine-faced plywood and not stressed. I simply butt-joined the pieces with epoxy. Another place on that boat's interior was the same sort of plywood tabbed to an ever-wet bilge/sole (same thing in this little raceboat). I removed the piece, the settee front, dried it, dug off the rot, coated it in epoxy, tabbed it back in and filled with epoxy and fairing filler. Trouble free. I painted all the Melamine surfaces and varnished the Teak trim so the interior had that Herreschoff look.