This is what I've done with all the others and what I favor in
general. We've had this debate before on this forum but I'll repeat
from the perspective of a boat designer.

The bronze through hulls are very reliable, far from the weakest link
in the watertight integrity. I have more faith in them and the solid
mechanical connection than secondary bonds over a small region of 26
year old fiberglass.

The through hull in this case however is a flush plastic transducer
fitting which has been replaced by one of the inside the shell units.
Since it is flush, the tapered hole has a lot less integrity against
impact and it's right up in the forefoot where something awash, like a
water soaked log, could impact it. I hate to add an unused through
hull to the several I already have now on this boat and it is up in
the very clean flow at the bow where it will create a lot more drag
than the ones aft the are in the boundary layer anyway.

If the hole were not beveled, I might just stick a capped through hull
in it but I don't like the flush ones on a cruising boat because of
the poorer support of the bevel. Any impact up here is likely to be
sideways that the glass plug will tolerate well where as the
projecting lip of a standard through hull could catch.

--

Roger Long



"Rich Hampel" wrote in message
...
Consider to put a bronze pipe cap and double nuts on the old
throughhull, then fill the beast with epoxy mush .... simply leave
it
in place, but 'deadheaded'.

.


In article , Bill
wrote:

Roger Long wrote:

Can anyone point me to some good on-line info on plugging old
through
hull holes in a fiberglass hull?

Any other advice appreciated. The yard wants 6% of what I paid
for
the boat just to plug one and put a new backing block in another.
I
hate working with glass but it looks like I'll be doing this
myself.

Did you look at the Don Casey book about fiberglass repair? He has
a lot of
good how to info and probably describes repairing fiberglass holes.