Southbay Motorboard Transom

[John Ki]

Is there any wood encapsulated in the transom part of a Southbay where the motorboard is attached ? I stole this picture from Steve Sanford.

 

[Anthony Babich]

There is about 1/2 of marine ply in there but i would strongly suggest a backing plate mounted in the interior side. Steve has a thread here about it: https://stevenjaysanford.com/another-south-bay-duckboat-ready-to-hunt/

 

[Dave Diefenderfer]

There is plywood inside as seen in my photo, and I had another piece on the outside between the hull and the motorboard to space the motorboard out from the deck flange.

I followed Steve's method!

 

[John Ki]

So the plywood is visible from the inside and you are able to see if it is rotted.

 

[Dave Diefenderfer]

So the plywood is visible from the inside and you are able to see if it is rotted.

Humm, now that you ask, I wonder if you have a hull without the bulkheads (foamed bow and sponsons) then maybe there is plywood within the glassed transom. I wish I paid more attention when I drilled the new holes. Reach out to Steve, he has done many more, and has some on site that he can inspect.

 

[John Ki]

Have not seen the boat in person yet will see it soon, owner says was built in 2001.

 

[Anthony Babich]

Humm, now that you ask, I wonder if you have a hull without the bulkheads (foamed bow and sponsons) then maybe there is plywood within the glassed transom. I wish I paid more attention when I drilled the new holes. Reach out to Steve, he has done many more, and has some on site that he can inspect.

Dave is correct, plywood within the glassed transom it's encapsulated between

 

[Dave Diefenderfer]

Have not seen the boat in person yet will see it soon, owner says was built in 2001.

Mine is a 1982, but obviously was not stored outside as it is solid throughout. Found no rot, even in the floor ribs with the flooring screwed into them.

 

[Steve Sanford]

So the plywood is visible from the inside and you are able to see if it is rotted.

John~

Earliest boats had not flotation compartments - so no plywood. The vessel in my shop right now is one such boat.

All others I've restored have plywood (half-inch) behind 'glass. I have not found any rot there yet. However, I recommend to everyone that they install 4-inch Beckson plates to provide access to both chambers (and a 6- or 7-inch plate up forward). What I have found is saturated flotation foam in some. It can be removed - piece by piece with whatever tools work - through the hole and then replaced with modern 2-part foam.

If you do have rot there, grub it out and replace. I would seal the new plywood with 2-coats of epoxy before installation - and I would bore holes for the Beckson plates on the bench. In fact, I would 'glass the "face" of the bulkhead on the bench as well - 7-5 ounce cloth with epoxy resin. I would secure the new bulkhead with thickened epoxy fillets followed by at least 2 layers of tape around the margin. I will be making a set of bulkheads soon and will post photos. I have taken the measurements from other South Bays with sound bulkheads.

Hope this helps!

SJS

 

[John Ki]

I appreciate all the info, I am going to look at a SouthbayTuesday. I have been reading everyones posts on all of the work they have peerformed.