Ball valve seacocks getting stiff to open/close......

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How best to lubricate? The boats being lifted in two weeks and I need to get the valves moving again or I fear its seacock replacement time. Any brilliant ideas?

TIA

Rob
 
Robih said:
How best to lubricate? The boats being lifted in two weeks and I need to get the valves moving again or I fear its seacock replacement time. Any brilliant ideas?

TIA

Rob
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Mine did the same last summer and got worse as the ball valve stem was leaking and jammed up with salt. WD40 kept it going until lift out in November where upon I replaced it. Looked at repairing it but the handle was corroded on, etc. It lasted about 14 years so can't complain to much.
 
Grease not much use on ball valves as they are stainless balls running in composite bearings. They are stiff through lack of use so deposits build up and prevent the ball from moving. Can usually be shifted by putting penetrating oil down from the inside and spraying from the outside. Good lever on the handle will also help, but handles are mild steel and can corrode. May need a bit of persuasion but once shifted should be OK. Avoid jamming by regularly operating. However I have just taken one out after 17 years and it works perfectly even though it was left open most of the time.
 
Tranona said:
Grease not much use on ball valves as they are stainless balls running in composite bearings. They are stiff through lack of use so deposits build up and prevent the ball from moving. Can usually be shifted by putting penetrating oil down from the inside and spraying from the outside. Good lever on the handle will also help, but handles are mild steel and can corrode. May need a bit of persuasion but once shifted should be OK. Avoid jamming by regularly operating. However I have just taken one out after 17 years and it works perfectly even though it was left open most of the time.
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Hmm not quite right as many ball valves are made from composite nylon/plastic. Only use marine grease.

Peter
 
rivonia said:
Hmm not quite right as many ball valves are made from composite nylon/plastic. Only use marine grease.

Peter
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What do you mean by 'marine grease'?

I carry silicone grease, PTFE grease and bog standard automobile grease, both lithium and calcium based. The latter three are certainly hydrocarbon based, not too sure about the first one. However, I would be fairly certain that none of them, nor penetrating oil, will have any significant effect on nylon. Just to illustrate this, the cages in the vast majority of greased car wheel bearings are made of nylon.

The only ball valve I have on board is in the galley sink drain. It is a standard nickel-plated ball, nylon trim type, probably 25 years old and never seizes. Apart from lubrication by kitchen discharge it gets nothing.
 
be carefull!

I had this issue a couple of years ago , I would confirm what others have said , no lubrication will work because you have a chromeed ball working with polymer seals.
Gently work it to and fro seems best

I say be carefull becuse it is quite easy to break the handle off where it joins the crosshaft.
I did this and had to change the valve in ahour on a boat lift (that makes you work really fast)

Hope this helps
 
The seals on the 3 part ball valves I have used are PTFE so should not need any lubrication but could become tight due to little critters growing on the outside of the closed ball. The valve should free up with some movement
 
I was told something this year that I hadn't appreciated. In the case of valves with a metal ball, the valves which are kept open don't get problems whereas the ones kept shut do, as the exposed metal corrodes or gets accreted, forming a rough surface that doesn't move across the plastic or whatever. This seems to be my experience, as valves such as cockpit-drains remain smooth, though I try to exercise them all regularly.
 
johnalison said:
I was told something this year that I hadn't appreciated. In the case of valves with a metal ball, the valves which are kept open don't get problems whereas the ones kept shut do, as the exposed metal corrodes or gets accreted, forming a rough surface that doesn't move across the plastic or whatever. This seems to be my experience, as valves such as cockpit-drains remain smooth, though I try to exercise them all regularly.
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Opposite of my experience. Corrosion of the ball is not the problem. As already noted it is the build up of deposits at the edge of the ball - calcium or marine beasties - that is the problem. Regular operation reduces the chances of buiuld up.
 
Try descaling with mild acid?
Mechanical cleaning? A length of frayed flexible ss wire rope in an electric drill is quite effective in cleaning inside pipes, but may not do the seals any good!
Some lubricant while moving the valve will help. GT85 seems very good on plastics and penetrates well.

Worth looking inside to see what the problem is. Corrosion, accretion, seal distortion etc.
 
Put your seacocks on your regular maintenance schedule. I operate mine half a dozen times each month & give them a quick spray of WD40. Never ever had a problem. (fingers crossed)
 
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