bertram31.com

I'm hoping I can get a lot of advice from this group given all the great rebuilds I've seen.

I bought my B20 about 15 years ago. It had been converted to an outboard, and the 1994 Yamaha ran fine. The deck and stringers were wet--really wet--but I figured I'd run it until the motor crapped out. During that time, I converted it from a moppie to my version of a center console. Its been the best boat ever.





Well, the Yamaha has enough problems that I decided it was time. She's going to need stringers, deck, and transom core to start. The motor is gone, and I inherited another boat (my late Dad's Edgewater--crappy way to get a boat) so I can still fish and take my time redoing the B20. She's in my yard wrapped up on the old roller trailer she came on.



First bit of advice needed--how should I support the boat before I start to tear the deck and stringers out? I have a friend who attempted a B20 rebuild using a local supposed fiberglass guy who supported his 20 by the keel and a couple of chine blocks and proceeded to cut everything out. When we went to see the disaster called progress, I could see the bottom of the empty hull deflect as the guy walked around the inside. I want to keep the hull shape true. I'm thinking of jacking the boat up off the trailer a bit, and building some type of cradle out of lumber with a keel timber and hull supports. Make sense? Any advice and/or pics would be great.

I would say a cradle built with plywood stations to support it every few feet. My 1961 31 came with cradle plans.

Prior to my B25 Project I got myself into a mess with a Hiliner 222 Gypsy. It is a Ray Hunt hull that is very similar to the B20. I bought the boat knowing the deck was soft in a few spots and thinking I'd re-do the transom and put down new marine ply for a deck and convert to outboard and then when I dug into it , the stringers were unbound on one side of the top-hat stringer on the outboard side. I ended up gutting it all and re-doing stringers from scratch.

During the process it was on a bunk trailer and I believe the bunks were supporting the hull well enough that it didn't distort.
https://photos.app.goo.gl/CZNChsiLCUyLaZgt7

John

I have never looked at a 20, but I am assuming that the stringers are not glass and are wood. If it is anything like the 3d1, the wood in the stringers can rot away and not impact the hull.

If I was building a cradle I would build it the way Bertram had them made. Supports in the 3 load points. Forward right around the windshield, mid ship (on the 31 just behind the engine right around the transmission and then midway between that point and the transom. I would use Three 2x12's lag bolted together running length wise on each side with a 6 x6 at the support points tying them together.

Then I would cut supports angled to match the hull. You will need to support the hull with blocks that screw into those supports and fit between the strakes. Now supporting those angled supports. The 31 had Plywood locking them in place plus a lag bolted support on each side holding it up.

Hopefully that would do it. But if the stringers are left in place, not sure that is needed, but I hear your concern. When we repowered the Diesel Shop set her on a level cement pad so she couldn't shift. It was blocked up in 3 places on the keel and then blocked up at the stern chine and stanchions midship and forward.

The boat was extremely level when they were done setting her up.

Good luck.

I wouldn't worry a bit.
I see the trailer has 4 double rollers on each side, thus plenty of support for the whatever little weight of this boat.
You can also take out one stringer at a time if you have concerns of rigidity.

You could also replace the rollers with some flexible wood supports. I did that on a thistle sailboat I was doing some work on the stringers one time.

Some 1x4's 8 feet long bend and can provide some support over a large surface area.

On a smaller boat - I actually flipped the hull - But some plastic down and fiberglassed a 48" x 36" section of the hull to support it on the trailer while I did another repair. I liked it so much that put tabs on and carpeting and used it on the trailer full time after that.

Thanks. I'll post up some pics. when I get to the next step.

my brain is bit fried with COVID, but I see a 2 or 3 point cradle, lined with plywood in a v-shape of the lower hull, but a few inches bigger. Lay soft foam over the plywood, lift and place the boat in the foam-lined cradle. snug as a bug in a rug!

If you decide to cut the cabin out to make it an open boat you'll want to install a brace underneath to retain the crown. Mine went flat when I cut all the center structure away. Took some work to restore the crowned shape.

Cam

ktm_2000 wrote: ↑Nov 8th, '23, 16:56 Prior to my B25 Project I got myself into a mess with a Hiliner 222 Gypsy. It is a Ray Hunt hull that is very similar to the B20. I bought the boat knowing the deck was soft in a few spots and thinking I'd re-do the transom and put down new marine ply for a deck and convert to outboard and then when I dug into it , the stringers were unbound on one side of the top-hat stringer on the outboard side. I ended up gutting it all and re-doing stringers from scratch.

During the process it was on a bunk trailer and I believe the bunks were supporting the hull well enough that it didn't distort.
https://photos.app.goo.gl/CZNChsiLCUyLaZgt7

In hindsight, a friend and I completely gutted and re-stringered a 30' Scarab Sport on a bunk trailer and it turned out fine. That would probably work OK and if you needed some extra support in spots you could just screw the extra bracing to the bunks to have the same effect as a cradle. at least you could still move it that way!