gate valve replacment

[alcodiesel]

Is this marlon 1 1/4" the replacement for the antique gate valve in the bottom pic?

[Tim]

It would be an improvement, but no. It looks like the valve connects to a thru hull fitting. If that is the case, you should replace the valve with a seacock. Also, get rid of any PVC fittings for any systems that connect below the waterline and replace them with bronze or marlon. Here are a before and a couple of after photos of my seacock upgrade a couple years ago.

[roadnsky]

+1 on Tim's advice.
Especially about getting rid of the garden variety plastic PVC.

When I first got my vessel, the gate valves on all of the Thru Hulls were my biggest concern. They are a time bomb just ticking away.
Here is another BEFORE and AFTER example.

[romantic comedy]

Thru bolted bronze seacocks are the only thing I would use.
rule number one: Keep the water out

[paulw]

thru hull maintenance

Hi

I've got the same through hulls on my Ranger 33, 1972. I'm wondering what resistance the fitting will put up, thinking that I'll use one wrench to keep the through hull from bearing the tension from the other wrench.

[JOHN COOKSON]

Side Note

If you open and close the through hull ball valves and any other ball valves once in awhile it will keep them from corroding or "freezing" in the open or closed position.

ex TRUE GRIT

[roadnsky]

I've got the same through hulls on my Ranger 33, 1972. I'm wondering what resistance the fitting will put up, thinking that I'll use one wrench to keep the through hull from bearing the tension from the other wrench.

Paul-
Are you doing the repair while still in the water or on the hard?

IF you're out of the water and don't mind spending a few boat bucks" you can use a Thru Hull tool. (About $50 new)
It makes the removal very easy.

IF you're still in the water, then dive in and plug the thru hull (from the water side) while you use 2 wrenches.
The down side to this is you won't be actually replacing the thru hull but just the valve.
I did this (while in the water) so I could get rid of my old gate valves and it lasted me for a couple of years until I could get hauled out for proper repair.
It's just a band-aid solution.

Be careful with the two wrench approach if in the water.
You don't want to let that thru hull turn. ONLY the valve.