This
is what I did on Grace (1983 M17 #400):
The original thru-hulls appeared to be
thin-walled aluminum tubing glassed into the hull. I believe the tubing was
primarily the form around which the glass was placed as well as the attachment
point for the flexible hose. I chose to replace them with 1-1/2" stainless
steel tubing which has a 1-1/2" outside diameter and is much sturdier than
aluminum. I ground out the remnants of the aluminum and glassed the ss tubing
in place. I am confident that no amount of banging around will damage my new
thru-hulls (at least not before the hull itself would
fail).
I
believe that bronze (not brass!) or stainless tubing would be best. Don’t
try to glass in the rubber hose directly. That would be asking for trouble (and
you would be certain to have that trouble show up at the absolute worst
possible moment).
Mark
Dvorscak
-----Original Message-----
From:
montgomery_boats-admin@mailman.xmission.com
[mailto:montgomery_boats-admin@mailman.xmission.com] On Behalf Of
Sent:
To: montgomery_boats@mailman.xmission.com
Subject: M_Boats: cockpit drain
thru hull fitting
I had a leak at the bottom end of
the cockpit drain on my '76 M17.
The metal pipe that goes thru the
hull had corroded.
I cut it out (6" dia. hole in
the bottom) and the metal tube had two small holes just below the
clamp from corrosion. (26 years old)
Does any one know what is the best
type of tube to replace it with, or if a clamping tube is necessary ?
Maybe I can just glass the rubber
hose directly to the bottom.
Some options for the tube are
Stainless, Brass, Copper or Marlon fittings from West Marine, or perhaps
a section of PVC pipe from Home Depot.
My only concern is which materials
are most compatabile with fiberglass and will develop a strong bond.
Also is it better to re-install it
in the new fiberglass as I repair the hole, or would it be better to install it
in
an adjacent area of uncompromised
(original) fiberglass. The hose is long enough that I can route it to a
different location.
The old tube looked like thin
wall aluminum, it was glassed into the bottom with the rubber hose
clamped to it.
Bob if you have any suggestions I
would greatly appreciate your input, or anyone who has dealt with a similar
problem..