Comments below:
"Trent D. Sanders" wrote in message
om...
Not sure I understand your reply,,, do you mean to say that tapered
[pipe] threads wouldn't "snug down" like straight threads? Seems like
when I do plumbing around the house that that's the case.

Maybe I should have asked the question of whether anyone makes a
straight threaded ball valve.

Trent
S/V Cimba

I'll try to explain what he meant. As you know tapered threads are tapered.
They are used for pipe fittings because as they are screwed together the
tapers come closer and closer together until all the space between the
threads is taken up and the fitting becomes tight. The threaded area can
only be so long as it tapers at a constant rate. If you tried to make a
tapered thread thru hull it wouldn't work because the threads at the top
would be way too loose and weak with not enough thread contact, and at the
bottom too tight for the ring to turn far enough to hold the thru hull tight
to the hull.

Make sense? You could probably get a plumber to re-cut the straight threads
into tapered threads on the top of your thru hulls but it would be better to
use real seacocks with regular thruhulls threaded straight in as explained
in an earlier post.
--
Ken Heaton & Anne Tobin
Cape Breton Island, Canada
kenheaton AT ess wye dee DOT eastlink DOT ca

Thank you for the info,,,,,,,,, now I have a clear picture of the
situation. Which "pains me" because when I had all [9] thru-hulls and
valves replaced on my Islander 29', the yard, the yard mechanics, the
salespeople [at Worst Marine] ALL said to put tapered thread ball
valves onto the straight thread thru-hulls.

Well, I may be an "expert" at flying a 747 but I don't [didn't] know
squat about thru-hulls and valves/seacocks. So I let them go ahead.
Only later did I read in 'Good Old Boat' [best magazine out there!]
that this is a "no no".

Live and learn,,,,,,, now I'll have to have it done over, but properly
this time.

Cheers,

Trent
S/V Cimba

"Ken Heaton" wrote in message ...
Comments below:
"Trent D. Sanders" wrote in message
om...
Not sure I understand your reply,,, do you mean to say that tapered
[pipe] threads wouldn't "snug down" like straight threads? Seems like
when I do plumbing around the house that that's the case.

Maybe I should have asked the question of whether anyone makes a
straight threaded ball valve.

Trent
S/V Cimba

I'll try to explain what he meant. As you know tapered threads are tapered.
They are used for pipe fittings because as they are screwed together the
tapers come closer and closer together until all the space between the
threads is taken up and the fitting becomes tight. The threaded area can
only be so long as it tapers at a constant rate. If you tried to make a
tapered thread thru hull it wouldn't work because the threads at the top
would be way too loose and weak with not enough thread contact, and at the
bottom too tight for the ring to turn far enough to hold the thru hull tight
to the hull.

Make sense? You could probably get a plumber to re-cut the straight threads
into tapered threads on the top of your thru hulls but it would be better to
use real seacocks with regular thruhulls threaded straight in as explained
in an earlier post.

Thank you for the info,,,,,,,,, now I have a clear picture of the
situation. Which "pains me" because when I had all [9] thru-hulls and
valves replaced on my Islander 29', the yard, the yard mechanics, the
salespeople [at Worst Marine] ALL said to put tapered thread ball
valves onto the straight thread thru-hulls.

Well, I may be an "expert" at flying a 747 but I don't [didn't] know
squat about thru-hulls and valves/seacocks. So I let them go ahead.
Only later did I read in 'Good Old Boat' [best magazine out there!]
that this is a "no no".

Live and learn,,,,,,, now I'll have to have it done over, but properly
this time.

Cheers,

Trent
S/V Cimba

"Ken Heaton" wrote in message ...
Comments below:
"Trent D. Sanders" wrote in message
om...
Not sure I understand your reply,,, do you mean to say that tapered
[pipe] threads wouldn't "snug down" like straight threads? Seems like
when I do plumbing around the house that that's the case.

Maybe I should have asked the question of whether anyone makes a
straight threaded ball valve.

Trent
S/V Cimba

I'll try to explain what he meant. As you know tapered threads are tapered.
They are used for pipe fittings because as they are screwed together the
tapers come closer and closer together until all the space between the
threads is taken up and the fitting becomes tight. The threaded area can
only be so long as it tapers at a constant rate. If you tried to make a
tapered thread thru hull it wouldn't work because the threads at the top
would be way too loose and weak with not enough thread contact, and at the
bottom too tight for the ring to turn far enough to hold the thru hull tight
to the hull.

Make sense? You could probably get a plumber to re-cut the straight threads
into tapered threads on the top of your thru hulls but it would be better to
use real seacocks with regular thruhulls threaded straight in as explained
in an earlier post.