Lubricant for gate valves

[pappaecho]

Whilst the boat if out of the water, I have noticed that the shutoff gate valves for the WC are quite stiff. They are easily disassembled, but what is the best lubricant??

 

[KenMcCulloch]

Whilst the boat if out of the water, I have noticed that the shutoff gate valves for the WC are quite stiff. They are easily disassembled, but what is the best lubricant??

Many would say the best thing you can do with your gate valves is to throw them away and fit ball valves. The reason is that with a gate valve you can never be absolutely sure it's fully closed, because a foreign body jammming it partly open would feel pretty much the same as a closed valve. DZR ball valves are not very expensive and much safer.

 

[andygc]

Many would say the best thing you can do with your gate valves is to throw them away and fit ball valves. The reason is that with a gate valve you can never be absolutely sure it's fully closed, because a foreign body jammming it partly open would feel pretty much the same as a closed valve. DZR ball valves are not very expensive and much safer.

Absolutely. I was once OiC of a Service recreational motor junk. We faithfully closed the toilet gate valve seacocks after every trip. After a typhoon came through the junk had a fair bit of water on board and sank by backflow through the toilet outflow cock. The seacock that felt closed had, in fact, lost most of its guts through corrosion. I later discovered that the previous OiC had known it was defective when he handed the boat over (afloat). Not something that you spot during the season. The b*****d.

 

[prv]

Many would say the best thing you can do with your gate valves is to throw them away and fit ball valves. The reason is that with a gate valve you can never be absolutely sure it's fully closed

In my case I threw them away because two of them had rusted inside so that, while the handle and spindle turned, the gate didn't move. The other reason normally given is that you can't see whether they're open or closed just by looking.

Pete

 

[philip_stevens]

Whilst the boat if out of the water, I have noticed that the shutoff gate valves for the WC are quite stiff. They are easily disassembled, but what is the best lubricant??

Further to what others have said, you ask about lubrication. I use blue waterproof grease from an outboard motor service/sales company.

You can see when it is closed, as the handle should turn through 100 to 120 degrees - not 90 - to fully close.

Yes, fit ball valves if you don't feel confident with the Blakes cone valves, but I have no problem with the valves fitted to my boat. I will be servicing/lubricating them for as long as they last.

The valves are bronze, but I believe the through-hull bolts are not bronze. These are the parts to carefully look at.

 

[Deleted member 36384]

Paul - once you have the valve lubricated just count the number of revolutions between fully open and fully closed. This way you will always know the position of the gate. Its standard practice on much bigger manual valves.

The only advice on lubrication I would offer is make sure that any O rings are compatible with the lubricant otherwise they will swell.

 

[macd]

Yes, fit ball valves if you don't feel confident with the Blakes cone valves, but I have no problem with the valves fitted to my boat. I will be servicing/lubricating them for as long as they last.

The valves are bronze, but I believe the through-hull bolts are not bronze.

Not sure where Blakes seacocks came into it. Wasn't the OP asking about gate valves? It's a common misconception but Blakes valves are very definitely not bronze. The body and plug are made of DZR1 (BSEN 1982 CC752C), a dezincification resistant brass. Source: www.blakes-lavac-taylors.co.uk/faqs4.htm

 

[Maine Sail]

Whilst the boat if out of the water, I have noticed that the shutoff gate valves for the WC are quite stiff. They are easily disassembled, but what is the best lubricant??

The best lubricant is some penetrating oil on the threads to remove gate valves from your vessel and throw them in the trash.

 

[philip_stevens]

Not sure where Blakes seacocks came into it. Wasn't the OP asking about gate valves? It's a common misconception but Blakes valves are very definitely not bronze. The body and plug are made of DZR1 (BSEN 1982 CC752C), a dezincification resistant brass. Source: www.blakes-lavac-taylors.co.uk/faqs4.htm

Sorry, just assumed Blakes valve as they were for the toilet - as are mine. That's why I said I "think" of the type of metal. I stand (or as at the moment, sat) corrected.

As said, if gate valve, get rid of it. I had one fail on me, and decided to dry out to change it ASAP.

 

[SHUG]

Just to add to the litany against gate valves. Got to the mooring , closed the gate valve and just gave it an extra tweak to make sure it was off and the whole issue came away in my hand. The thread at the top of the tap body had corroded and the whole inner assembly came away.
If you are going to retain gate valves I would suggest that youu completely dismantle them each year and coat the moving surfaces with waterproof grease.
What was the question...ah ..yes...
The answer is... waterproof grease.

 

[Talbot]

Another problem with gate valves is the little barnacles migrating to the gate valve closing area, and committing suicide there, such that their skeletons stop the gate valve closing even if the **** things are properly lubed up.


Get rid of them, they have no place in a marine environment.