J36 - J35 Bulkheads

benjicohn

New member
Hi all. I'm a longtime lurker first time poster.

I'm looking at a J36 that needs some (a lot of) work. Lots of -at minimum- cosmetic water damage to the main bulkhead that the chain plates bolt through.

On the J36, does anybody know if this bulkhead is balsa cored or solid fiberglass? Does the plywood play any role here, or is it truly cosmetic. Is this the same on the J35?

Thanks in advance.

Ben.

 

Squalamax

Super Anarchist
2,521
67
Hi all. I'm a longtime lurker first time poster.

I'm looking at a J36 that needs some (a lot of) work. Lots of -at minimum- cosmetic water damage to the main bulkhead that the chain plates bolt through.

On the J36, does anybody know if this bulkhead is balsa cored or solid fiberglass? Does the plywood play any role here, or is it truly cosmetic. Is this the same on the J35?

Thanks in advance.

Ben.
The bulkhead is balsa core between two skins of glass. The plywood(or veneer) is purely cosmetic. 

 

Squalamax

Super Anarchist
2,521
67
Call J/boats and ask them.  Im pretty confident they have never used balsa in a main bulkhead application. 
You would be 100% mistaken. My 29 has a balsa cored bulkhead as well as all the 30's. The 30 used the main bulkhead from the 36.(obviously cut down) 

 
My 35 ('83 production) has a teak veneer over a layer of marine plywood on the cabin side of the bulkhead (maybe 5/8 or 2/3), tabbed in and sistered on the V-berth side with maybe a half inch of solid glass.  Just had one side repaired last year due to water intrusion.  No balsa.  Interestingly there was very little water damage in the actual bulkhead, the teak veneer had delaminated and created seeming soft spots. The yard thought it would be okay with the existing wood but we cut out anything that was soft and sistered new plywood in and they re-tabbed the top of it. 

Seal your damn chainplate cover fittings on the deck every year or so.  It was a pain in the ass of a repair.   

 

PaulK

Super Anarchist
We had a J/36 for 24 years, with a ship's bell clock mounted on the main bulkhead to starboard.  The screws that went into the bulkhead to hold the clock did not encounter any balsa. On the other side of the bulkhead, to Port, is the head.  The screws that went into the main bulkhead to hold the toilet paper roller did not encounter any balsa either. We replaced the veneer when it buckled around the chainplates from getting wet and had no problems with the bulkhead.  

The boats are a blast to sail.  We got ours up to 12.5 knots, downwind under a reefed main.  Racing we enjoyed occasionally passing J/109's and J/120's.  Cruising is also fun. The boat is big enough to be comfortable and quick enough to go far.  We explored ports from Northeast Harbor, ME, to NYC, and had a blast with ours.

 

benjicohn

New member
This is all great, thanks to everyone here. I heard back from J/Boats that to their recollection the J36 does have a balsa cored molded bulkhead. I'll just have to do a better inspection to find out.

PaulK thanks for this tidbit - from your first hand experience it sounds like there is no balsa. The veneer is definitely buckled around the chainplates but hopefully no problems lurk beneath...

Thanks again,

Ben.

 
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Squalamax

Super Anarchist
2,521
67
This is all great, thanks to everyone here. I heard back from J/Boats that to their recollection the J36 does have a balsa cored molded bulkhead. I'll just have to do a better inspection to find out.

PaulK thanks for this tidbit - from your first hand experience it sounds like there is no balsa. The veneer is definitely buckled around the chainplates but hopefully no problems lurk beneath...

Thanks again,

Ben.
I know for a fact that the J30 and J29 have balsa cored main bulkheads. I've worked on both. What's funny is a lot of J29 owners will swear their bulkhead doesn't have balsa in it. They are mistaken. It was common for TPI to build them that way back then. 

I would investigate your J36 a bit more. 

 

JCoggs

New member
11
0
Where is the J/36 located? Could be my old boat that I sold around 1994.  I heard it was still afloat in the Pacific North West and for sale last year.  Sail number was 36528.

ceilidh 1.JPG

 

benjicohn

New member
Hi all, didn't want to leave a question mark hanging here. Boat was in Norwalk, now in New Rochelle.

I finally had a chance to take some bolts out of the chainplates. The bulkhead Looks to be about 5/8" to 3/4" thick solid fiberglass, with wood veneer only on both sides - there does not appear to be any plywood. Needless to say I'm greatly relieved.

Though I am surprised that there was plywood on your J35 bulkhead Lex, since it is from the same year and basically the same hull.

Thanks for all your help!

Ben.

 
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Crash

Super Anarchist
4,938
919
SoCal
Hi all, didn't want to leave a question mark hanging here. Boat was in Norwalk, now in New Rochelle.

I finally had a chance to take some bolts out of the chainplates. The bulkhead Looks to be about 5/8" to 3/4" thick solid fiberglass, with wood veneer only on both sides - there does not appear to be any plywood. Needless to say I'm greatly relieved.

Though I am surprised that there was plywood on your J35 bulkhead Lex, since it is from the same year and basically the same hull.

Thanks for all your help!

Ben.
Its possible, and I don't actually know, that the bulkhead is solid glass at the chainplates, and plywood or balsa cored elsewhere...

 
Last edited by a moderator:
Hi all, didn't want to leave a question mark hanging here. Boat was in Norwalk, now in New Rochelle.

I finally had a chance to take some bolts out of the chainplates. The bulkhead Looks to be about 5/8" to 3/4" thick solid fiberglass, with wood veneer only on both sides - there does not appear to be any plywood. Needless to say I'm greatly relieved.

Though I am surprised that there was plywood on your J35 bulkhead Lex, since it is from the same year and basically the same hull.

Thanks for all your help!

Ben.
I assume there are variations in the manufacturing process, and don't take it for granted that mass production boats are identical.  Owners can order changes sometimes, the manufacturers can switch materials during a busy production run, and there is no accounting for subsequent repairs on a 38 year old boat.  And now that I think about it, we only had a 2' x 2' area around the port chainplate open for the repair - so I can't vouch for what is in the remainder of the bulkhead.  The bottom half definitely has cored glass of some type, we've drilled into it to mount hardware in the head.  

We also have an oddball keel, with a 2.5" shoe affixed to the bottom to bring the keep up to class depth. I've heard that a significant number of boats in the class have this mod.  That wasn't to design spec either. Life's great mysteries.

 

PaulK

Super Anarchist
Hi all, didn't want to leave a question mark hanging here. Boat was in Norwalk, now in New Rochelle.

I finally had a chance to take some bolts out of the chainplates. The bulkhead Looks to be about 5/8" to 3/4" thick solid fiberglass, with wood veneer only on both sides - there does not appear to be any plywood. Needless to say I'm greatly relieved.

Though I am surprised that there was plywood on your J35 bulkhead Lex, since it is from the same year and basically the same hull.

Thanks for all your help!

Ben.
Glad I was right about no ply core in the bulkhead.  If you're taking out chainplates you must have bought her.  Have FUN!  We sailed ours for 24 years before selling her last June.  Great boats. Capable, responsive, easily handled, and fast.  Talk to Hunter Riddle at Schurr Sails if you're out looking for silver.  

 
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