1968 B20 BAHIA MAR

[bertram 20]

I know this site is for 31s but i thought i would ask anyways. this boat has been in my family since 1972 roughly i have been trying to keep her in pretty good condition but i have recently noticed transom is wet.i would like to repair this winter can any one give any info on doing this job and were to start remove engine transom plate etc then what? any info on this would be great thanks

[In Memory of Vicroy]

You are looking at a huge job and I'd think twice about doing it. My 1969 B20 Bahia had a wet transom core and I had it repaired professionally and it cost a ton.....plus the cap at the stern has to be cut out, the drive and engine removed. My guys used two layers of 3/4 marine ply and epoxy and it's stong as Fort Knox, but the glass on both sides of the coring is so thick I seriously doubt the core adds any strength to the equation at all.....now maybe if you were going to put a new hi HP engine it sould be done, but I recall Capt. Patrick opining that the core is not needed due to the thickness of the transom glass.

UV

[John F.]

UV may be right, I have no idea. There is a Bertram 20 section on 25bertram.com that you may want to check out. I tried registering so I could post there (I have a B20 Moppie), but I'm still waiting for the Administrator confirmation or whatever--been waiting more than a year. Lots of good B20 info. there.

John F.

[CaptPatrick]

I'm still waiting for the Administrator confirmation or whatever--been waiting more than a year.

John,

Send RussP a few emails.... Hey Russ, you listening??

[In Memory Walter K]

Patrick told me, when I asked him that question a few years ago, that unless I was planning to put in a much bigger engine, the degree of fiberglass on both surfaces of the transom can easily handle the stress of the original engine or a similar repower on a B-20. You are correct, to redo the transom the engine, stern drive, etc have to all come out. You can do it from the inside or the outside, but you would have to cut fiberglass, replace the wet balsa and re-sandwich the three surfaces, then re fair (if it's done on the outside) and repaint it to it's original glory. I found the culprit to be the scuppers that were poorly installed. I pulled out the sleeves in them with two fingers. Let them air out for quite a while and reinserted them back after smearing 5200 all around the inside. There's more glass on a wet B-20 transom than some boats have on their hulls. If I was going to replace the inboard with an outboard I think I would definitely do it, but unless you were planning that, I'd think twice about the job. The Bahia Mar model has a big cap on the transom that makes it even more difficult

[tunawish]

Bert 20 send me a pm, I have the exact same boat and I am in Ma.

Ray

[JohnD]

I had the transom in my b20 replaced with coosa board 1-1/2 years ago and it cost $2500. The repair was done from the inside the inner-floor was cut from either side of the motor well and removed. The foam fwd was solid and left in place. When the repair was done the inner liner was replaced and filled with closed cell foam.

I considered the repair myself, but when I added up the cost of materials I quickly came to the conclusion that it was better to pay someone else to do the work.

So I think to answer your questions. You will need pull the motor and the outdrive parts (not real hard, but like in my case i found the inner-shield could not be reused and I had to find a new one.) In a perfect world I would have had the transom rebuilt and installed a new volvo 4.9l v6 with duoprop outdrive.

If you have any more specific questions please let me know.

br,
JohnD

[bob lico]

ok brothers i will attemp to post in proper english i don`t want anybody to misunderstand .recently coosa composites have blown away all competition for structual strenth compare to nidacore,divinycell,balsa core.now there is a trasom repair that beats all. becomes steel and was used to hang 6 -350 hp yamaha outboards off of.the product is called seacast trasom repair.
a 20' bertram would be done by removing inside panel like john describe .remove foam .reline with coosa leaving gap in between outside glass layer, then fill with seacast.totally w/p for a hundred years and strong enought to hang a 350 hp yamaha on.



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