Glassing over keel joint

[NPoole]

While refurbishing my '78 t-bird (glass over ply), I noticed that the glass has cracked around the joint with the keel. I want to redo this area, but I'm concerned that the same thing will happen again. First of all,
I imagine that there would be a certain mount of flexing by the keel, which likely has caused the cracking in the first place, and I was also under the impression you cannot glass directly to metal because the difference in thermal expansion rates between metal and glass will cause the glass to lift off. So what's the best way to deal with
this area?

[Ed Harrow]

Seems like someone ought be be able to help this guy, so I'm bringing this back up to the top...

[NPoole]

Hey, thanks; I was kind of wondering if "fiberglass" was a bad word on the WoodenBoat Forum; honestly, a T-bird constitutes a wooden boat, even if it has a ****** skin. I can tell by all the work she needs...

[BrianCunningham]

was it originally suppose to be glassed over?
Or was the keel suppose to be bolted on over it sealed in a bedding compound?

Glassing over the rest of the joints in a ply hull is not only common but recommended.

Can you post a picture?

[ken mcclure]

Yep. It's a bad word. Now go wash your keyboard out with soap.

[paladin]

The T-bird flexes.....and the area where the keel bolts on is not especially rigid. A minutely flexible epoxy is preferable with a polyester fiber like Xynole or Vectra polyprpylene. I laminated doubles inside my bird and "frames" on the topsides to get some rigidity. Good Luck....

[rbgarr]

Wasn't there an article about the Thunderbird class in WB a while ago? I think there's a very active class association, and you're question might be addressed by someone there who has dealt specifically with this.

[NPoole]

The keel is embedded in the hull, and the glass is lapped over the joint. See pic below. The old glass has adhered to the metal keel, but I'm not sure if they used a special technique for making the stuff stick. Could one just stop the glass at the joint, and caulk the seam instead? What's really scarey was someone's suggestion that I should replace the keel bolts - seems awfully early for a twenty-three year old boat that's been on drydock for the last five.
There is a class association and forum on the 'net for birders, but judging from the lack of response, it's not very active...
_________________
-------I_______ ________I--- Hull
-------------- | |----------- Glass
Glass | |-KEEL
| |
|