1970's catalina Seacock size?

[jado27]

I have a 1974 Catalina 27 and need to replace the old gate valve on the sewage through-hull. (Yes I know the entire through-hull needs to be replaced) But I dont plan on hauling the boat out till next winter.
I have searched all over multiple sail forums and catalina direct for information on through-hull diameter sizes on earlier 1970 Catalinas with no success.

I cannot tell whether the through-hull bronze nipple diameter is 1.5 (1+1/2) inches or 1.25 (1+1/4) inches?? Also can anyone verify the thread type?
Has anyone replaced just the valve and know? I know some of the earlier sailboats had smaller through-hulls then standard.
The nut size is exactly 2 inches, but I cannot see the nipple as it is fiberglassed up and just over the old gate valve. I went to get a 1.5inch seacock and it just looks way to big, but I know the old gate valves were very thin walled.

Thank you all for your help. I am new to the site, and new to sailing (just bought the cat 3 months ago)

 

[Joel H.]

I believe the size are the markings cast into the valve right there in your picture. Can you wire brush that and try to give it a read.

 

[Old Skool Neil]

Measure the O.D. of the nipple coming out of the top of the valve with calipers. If it's in the area of 1.625" (1 5/8") the valve is 1¼", if it's in the area of 1.875" (1 7/8") the valve is 1½".

 

[The Garbone]

All my yard estimates list 1.5" seacocks. My 74 is being pulled Monday so I will know for sure next week.

 

[Maine Sail]

I have a 1974 Catalina 27 and need to replace the old gate valve on the sewage through-hull. (Yes I know the entire through-hull needs to be replaced) But I dont plan on hauling the boat out till next winter.
I have searched all over multiple sail forums and catalina direct for information on through-hull diameter sizes on earlier 1970 Catalinas with no success.

I cannot tell whether the through-hull bronze nipple diameter is 1.5 (1+1/2) inches or 1.25 (1+1/4) inches?? Also can anyone verify the thread type?
Has anyone replaced just the valve and know? I know some of the earlier sailboats had smaller through-hulls then standard.
The nut size is exactly 2 inches, but I cannot see the nipple as it is fiberglassed up and just over the old gate valve. I went to get a 1.5inch seacock and it just looks way to big, but I know the old gate valves were very thin walled.

Thank you all for your help. I am new to the site, and new to sailing (just bought the cat 3 months ago)

I would strongly urge you to NOT attempt the removal of that valve with the boat in the water. With those "glassed in" volcano style pipe nipples you are VERY likely to spin it in the fiberglass and create a leak.

I am amazed to even see one of that vintage not leaking. Thousands of these failed and leaked over the years so to even have a boat that has not been converted is a rarity and certainly "pushing" the envelope..

This is a job best suited for a haul out..

 

[philwsailz]

I agree with Maine. Having removed one to glass the big hole over on a 75 C27, I can tell you that it is easy to spin it. Wait.

 

[foolproof]

As a point of interest, I replaced mine while the boat was on a stand. Good thing too, because when I tried to remove the valve by turning it, the threaded nipple started turning, then popped out in my hand!

If it isn't leaking now, leave it until you haul the boat and replace it then.

 

[jado27]

The outside thread diameter is about 1.6 inches so I'm thinking its inch and a quarter pipe then. I'll try and wire brush the corrosion for markings. My marina has a shop and can hoist me out if I need but I'm gonna at least try swapping the valve in the water. I'll counter the torque with channel locks and have been putting penetrating oil on the valve threads for weeks. Fingers crossed.

 

[The Garbone]

The outside thread diameter is about 1.6 inches so I'm thinking its inch and a quarter pipe then. I'll try and wire brush the corrosion for markings. My marina has a shop and can hoist me out if I need but I'm gonna at least try swapping the valve in the water. I'll counter the torque with channel locks and have been putting penetrating oil on the valve threads for weeks. Fingers crossed.

Have you soft wood plugs and hammer ready in the event it goes wrong. I would put lanyards on both for going over the side.

 

[jrowan]

While you need to replace any of those origianl crappy gate valves that Catalina used on your boat, I think think its fool hardy to replace that valve whilst in the water. You will be shocked at the amount of water pressure that blows through wheh the valve is removed. Very difficult to install a new valve with the tremendous influx of water coming in. If you can't get the new valve on, you risk flooding your boat. Not worth the risk. Its winter anyways, so its a good time for a haul out & do the job right. Plus I've never known a sailboat that was in the water for a season or more that didn't need a botom job on the hull - so get 2 birds with 1 stone, & better sailing performance to boot.

 

[Ajay73]

I replaced all my through hulls with 3/4 " flanged seacocks. The glassed in nipples were all 1/2". One thing I will say is that on my boat those glassed in nipples were a bear to get out. I tried putting a pipe wrench on them and they wouldn't budge. I had to saw out quarter sections of the nipple from outside the boat with a sawzall and the narrow bimetal blades after taking off the ball valves on the inside and cutting the nipple off flush to the hull.