Repair of hole in plywood GP14
 

I'm currently working on a rather neglected GP14 and wish to repair a
sizable hole towards the bow, close to the keel (see
http://xdev.net/~jon/pict1679-resized.jpg). I've stripped back all the
rotten wood around the hole and am wondering how to proceed.

My current idea is to cut back the hole to a straight edge, produce a lip
around the edge of the hole by removing half the plys of the existing wood
and make a patch to fit (with an opposite lip). I then plan to epoxy this
in place and possibly brace it on the inside. I could then use marine
filler to shape over the top of the patch to the curvature of the bow.

Does this plan sound sensible, or can anyone suggest how I should proceed?

Many thanks.

Gougeon Brothers has an example of such a repair in one of their boat
maintenance/repair pamphlets. The cut back to make the hole rectangular,
then used a sharp chisel and low-angle block plane to cut an 8:1 ratio scarf
on all 4 sides. Looked a lot like a picture frame. Then they cut a piece
to match and again used a plane to cut the scarfs, fitting it as they went.
Then they just scarfed it in per usual (pre-wet grain, glue with thickened
epoxy, screws or thin nails through the joints). Just fill and coat, then
paint. Your stair-step type scarf might be fine too, depending on the size
of boat and horsepower involved. You could also fit a piece in so that it's
the equivalent of a butt joint on all 4 sides, then overlap the joint with a
butt block (epoxied in) on the inside of the boat. That might be easiest if
the repair is either where you won't see it or you aren't worried about
aesthetics. I've seen boats with butt blocks on the inside and outside,
like a square patch, before. Work boat or pretty boat or somewhere between.
It's your boat and you'll be proud of having put her back in service.

Brian D



"Jonathan Griffiths" wrote in message
...

I'm currently working on a rather neglected GP14 and wish to repair a
sizable hole towards the bow, close to the keel (see
http://xdev.net/~jon/pict1679-resized.jpg). I've stripped back all the
rotten wood around the hole and am wondering how to proceed.

My current idea is to cut back the hole to a straight edge, produce a lip
around the edge of the hole by removing half the plys of the existing wood
and make a patch to fit (with an opposite lip). I then plan to epoxy this
in place and possibly brace it on the inside. I could then use marine
filler to shape over the top of the patch to the curvature of the bow.

Does this plan sound sensible, or can anyone suggest how I should proceed?

Many thanks.

With the block inside reinforcing the butt joined patch there will be a
flat stiff spot but it makes a faster repair.

Scarf joined type repair harder to match perfectly, all around. Might
still be best to have an interior flange as it makes clamping the scarfs
easier (ie small, through screws).

The stiffness should be no problem, but you may have to fair with
microballoon or microsphere thickened epoxy so as to match the hull's
curvature in that area.

Brian D



"Frogger" wrote in message
k...
With the block inside reinforcing the butt joined patch there will be a
flat stiff spot but it makes a faster repair.

Scarf joined type repair harder to match perfectly, all around. Might
still be best to have an interior flange as it makes clamping the scarfs
easier (ie small, through screws).