Pete C wrote:
On 28 Sep 2005 13:34:37 -0700, "bob" wrote:

Hello Steve:

Thanks for the reply. 3'x5' chain plates? Must be a big rig?!?

I'm not looking for an argument here. Just trying to muck my way
through boatbuilding tradition. I'm sure you've found in a few
insistences that the reason it is the "best way" is because they have
always did it that way. Time marches on and so do innovations. I may
very well find myself going with a polysulfide. But.....

However, I am hoping there is something "better" than polysulfide and
5200. My big question is: why does 5200 fail? You mentioned that it
does not take a squish very well. I know that 5200 can not handle temps
over 150 well. 3Ms data says 5200 can elongate 1300% with out
failure. So the pull in a gap should not be the problem. May the
problem is in the pinch?
Why do you say that 5200 can not take a squish? Is it damaged and lose
the bond??

Have you ever heard of Silaprene or used it?

Still in search

Hi,

Are you talking about bedding chainplates on the outside of a hull or
sealing where they pass through a deck?

Excellent question.......... plates measure 1/2"x 2 1/2"x 20" and pass
through deck. Deck is cored: 1/4" glass, 3/4" end grain balsa, 1/4"
glass.

Plan on digging core out and potting with thickended epoxy. But still
confused about the next step: 5200 or ? to fill 1/4" gap between plate
and epoxy.


For bedding I'd use eg 5200, mold release wax and some sort of spacers
to create a gasket, then seal the gasket and bolts holes/threads with
a sticky non setting compound.

Hummm. I like the sound of that.
The above is for plates bolted to a hull?
So suggestions for plates through deck?

I'd expect most problems occur where something is used to bed stuff
which is then tightened down too much initially, leaving a layer that
is too thin to take any movement and cannot be compressed further.

Agreed. This is exactly what I have found with all other through deck
bolts. Big problem.

Things were alot easier when all I had to do was pour hot tar around
the hatch/deck channel. Not exactly yachat standards. But worked fine
til the next offload.

Thanks for the rply Pete,
BOb


cheers,
Pete.