Anatomy of a Bertram 20?

[Ironworker]

I need some help with questions regarding a 20 Bertram. Does anyone have any original construction plans for a B20? Was there wood used in other areas with the exception of the stringers and engine sleepers?

Mine was at some point converted to an outboard with an Armstrong bracket. My B20 leaks. It had a couple of thru hull transducers, a grounding plate and a thru hull fitting with a sea cock. All of it looked kind of strange. The seacock was not bolted down and it was sitting on a flat area behind the fuel tank. The transducer was sitting in a recess with about an inch of threads showing and the grounding plate bolts had virtually rotted out.

After I started demo it appears as if there was a double hull with rotted wood sandwiched in between. Basically the wood was rotted to just liquid. Whoever did the original installation should never be allowed to work in the marine industry again.

[Ironworker]

Here are a couple of photos including a 4 x 12" steel plate that was glassed into this mess.











I should have took some pics before I started tearing stuff out but what I thought was going to be a straight forward removal of a seacock has turned into a major project.

[HotSpot]

Hi Rick

On my 25, all the thru-hulls are backed by plywood squares about 4-5”. Is it possible that someone later glassed straight over that, including the steel plate when replacing the original fitting?

[Yannis]

Rick,

Is all the hull sandwiched with this rotten ply? The sides too?
If yes, how will you establish the degree of rot? Will you be cutting through the inner glass until you find dry?
Holy hell, that's some job...

[Ironworker]

Hi Rick

On my 25, all the thru-hulls are backed by plywood squares about 4-5”. Is it possible that someone later glassed straight over that, including the steel plate when replacing the original fitting?

I don't think so. There are no backing plates or nuts on the hull fiberglass but on top of the inner liner glass which meant it was a recipe for a boat to sink at some point.

[Ironworker]

Rick,

Is all the hull sandwiched with this rotten ply? The sides too?
If yes, how will you establish the degree of rot? Will you be cutting through the inner glass until you find dry?
Holy hell, that's some job...

I don't know the full extent of this mess just yet. I'm hoping its just where the old engine bay was located. I got rained out today and it's likely to be a couple of weeks before I can get back on this job.

I'm going to cut out as much as I can without removing the floor but I'm not looking forward to that job.

[John F.]

Mine was converted to a transom mounted O/B and as far as I can tell, there’s no double hull like you’re finding. I’ve put a thru hull transducer in, and the bottom of the hull was solid f’glass. The 20s do have a wood covered in glass back bone down the keel. Good luck on your project. I have way too much experience with seemingly easy stuff turning into big projects.

[Tony Meola]

Rick

That thru hull was definitely not original. Like John said, they never used wood to core the hull.

I bet the plywood block rotted out and they jury rigged something to act like a backing plate which really wasn't right.

[Yannis]

Yes, but how did they manage to insert ply between two layers of glass, of which the top one was the original sole?
Unless if the top glass was not original. In which case its outline can be clearly defined and gutted.

[mike ohlstein]

The two things that I remember from my 20 Barron are that the only wood was in the transom (rotten) and the hull was self sinking, not self bailing.

[S Ritzert]

drill some small holes around the boat, and see if its cored. I can't imagine it being cored through the entire boat, unless someone laid ply, then glassed over it. If that's the case, just lift the plug out

[MarkD]

I agree with Mike O. My Baron had wood in the transom but I believe the rest of the hull is all glass.

[Raybo Marine NY]

Maybe someone cut the bilge liner a long time ago and glassed a metal pad for the seacock?
Could have been a void there so this was their solution , personally I would have just added a lot more glass and no steel plate

Easy work during a repower and usually includes a fresh bilge coating

but many manufactures used to glass plates where underwater gear would be mounted.

[Ironworker]

The metal piece was just laying in there, not connected to anything. I suspect the culprit didn't want to demo anything so just put a couple of layers of glass over the mess, which is going to make it twice as difficult to clean up the mess.

The guy that gave me the boat had it converted from the old Inboard to an outboard with a Armstrong bracket. He also had the floor raised up so that it would be self bailing but it sure doesn't look self bailing to me. I think self sinking is the more accurate term.

[Raybo Marine NY]

Your original post and photos showed the valve with the fiberglass still attached, and a “4x12 steel plate that was glassed into this mess”

[ktm_2000]

Unfortunately I know where this project goes.................

I had come across a hiliner 222 gypsy which was a 2nd generation hull designed by Ray Hunt off the B20. I knew the deck was soft and was planning on re-doing the transom to convert to an outboard so I was up for a project. The interior stringers were fiberglass like my B25 but they were filled with foam and on the port side become unbonded from the hull.

I ended up taking EVERYTHING out and starting from scratch fabricating plywood stringers, glassing them in, nidacore deck, etc

In the end the boat rode like a dream

but alas side by side with my B25, it did most but not enough of what the B25 could do so when I redid my B25 I sold her to my buddy who still has and runs the boat, this buddy has no ambitions of offshore fishing and it works out perfectly for him.