I could not worry about thermal cycling. I laid up an entire head, 3
FRP over foam composite bulkheads, in vertical grade formica using
contact cement. Rolled it with the J-roller till I thought my arms
would drop off. Trimmed to shape and tabbed them into the hull. This
was pro grade cement from Meyer laminates not the water based junk from
Home Despot. Six months later it was lifting at the edges and had come
loose in the curved corners. Ripped it all off and spent a miserable
weekend with remote air breather scrubbing the bulkheads with contact
cement solvent.

The next weekend I spread mixed some epoxy/silica to catsup consistancy
and vacuum bagged on new Formica. That was two years ago and after two
summers up to 105 and two winters down to 0 it is still solid.

Ron Thornton wrote:
Glenn,

Have you done any thermal cycling to test the joint for shear. I would
like to use epoxy for this kind of thing cause I hate messing with
contact cement.

Regards, Ron


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Glenn, thanks for your counsel. The noise i hear in the background is the
vacuum pump, bagging the galley counter.
I debated the foam sandwich approach, but for 4 ft^2, it seemed to have as
big a payoff as milking mice. Used 1/4" ply.
Jim

Glenn Ashmore wrote:

I could not worry about thermal cycling. I laid up an entire head, 3
FRP over foam composite bulkheads, in vertical grade formica using
contact cement. Rolled it with the J-roller till I thought my arms
would drop off. Trimmed to shape and tabbed them into the hull. This
was pro grade cement from Meyer laminates not the water based junk from
Home Despot. Six months later it was lifting at the edges and had come
loose in the curved corners. Ripped it all off and spent a miserable
weekend with remote air breather scrubbing the bulkheads with contact
cement solvent.

The next weekend I spread mixed some epoxy/silica to catsup consistancy
and vacuum bagged on new Formica. That was two years ago and after two
summers up to 105 and two winters down to 0 it is still solid.

Ron Thornton wrote:
Glenn,

Have you done any thermal cycling to test the joint for shear. I would
like to use epoxy for this kind of thing cause I hate messing with
contact cement.

Regards, Ron


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com