Jammed spi pole ends

[DeeGee]

Does anyone else suffer from this dreaded disease? The pistons in the pole ends tend to jam up, and when freeing them up with WD40, I find gunge that is probably salt being expelled from the piston cylinders. Catches me out toward end of season. Any other solution found?

 

[jamesjermain]

Regular maintenance is the only answer. Racing crew tend to use WD40 or similar, but this washes away in a week or two. Light oil is a better cruising option or even a light grease

 

[forestay]

What we need here is one of those clever metalogist types that can explain galvanic action or whatever it's called.

They could probably also explain why using WD40 or an equivalent is not good unless you clean all traces of WD40 off whatever it is that needed freeing afterwards and then grease it up nicely. KY jelly is not an appropriate grease.

 

[Evadne]

Yes I have this problem and I use oil and a good waggle with a pair of mole grips before using each trip. WD40 is ok for a while but I have beeen trying a lanolin based one which lasts a bit longer, though it is still stiff. (It was a free sample and I'll look up the name next time I'm on the boat)
One was jammed completely and I followed the various advice from here and elsewhere, i.e. boiling in vinegar & fresh water, also using a dremel to round off some sharp corners and burrs. This freed it to a certain extent but the problem is still there. A stainless steel piston in an aluminium casting is the root of the problem, methinks.

 

[DeeGee]

I am a bit inclined to think that the seals are the problem, and an improvement in the design, to allow dismantling and replacement of the seals each year would be good for us, and good for the manufacturers by way of a dribble of small sales down the years.

JJ - I dont like the idea of grease or oil.. a) not wanting anything to get on my spi corners and ropes and b) I hate grease or oil anywhere as they seem to attract dust and muck and create nasty dirt. So far, I have v successfully used a teflon spray elsewhere on the boat where grease or oil would otherwise be used. These pole ends are just asking for the piston chambers to fill up with salt.

 

[cliff]

I think you mean "one of those clever METALLURGIST types" but we know what you mean.
Anyway the problem with Spi pole ends in never ending and will remain so while the manufacturers continue to have a sliding "piston" running in a cast aluminium housing. It is a little complex to describe in words the electro-chemical cell arrangement and I cannot be arsed finding a picture to post but once the ali starts to corrode it will continue even if the Stainless piston is removed unless one can disrupt the electro-chemical cells.
I am sure there are many out there with their own pet theories as to the best method of prolonging the service intervals but in my case I have found the following to work well for between 1 to 2 seasons.
Thoroughly clean all corrosion produce from the piston/casting interface preferably by removing the piston and using mechanical means. Failing that copious quantities of "plus gas" or similar.

Keep working the piston until it is really free and no more "dirt" comes out - this is important.

A dilute solution of Formic acid and (hot) water helps.

Thoroughly wash and dry the end then apply a dry silicon spray such as "STEM".

Work this well in between the piston and the ali housing.

STEM is a silicon spray that evaporates leaving the silicon lubricant behind but will not mark sails or sheets - no obscene comments please, and is available in most sewing shops or commercial sewing accessory suppliers.

Depending on the type of sailing one does this treatment should last a couple of seasons.
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“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo

 

[TigaWave]

ACF 50.....or Corrossion block
It removes the corrosion which seizes any alloy/stainless junctions like the pin and the surround. WD and all the other lubricants just dont work nearly as well. You'll have to search for ity but its sold by an aero company at Hurn Airport Hampshire. I can gurantee you'll be impressed with how quickly it works and how long it carries on working.

 

[DeeGee]

[ QUOTE ]
I think you mean "one of those clever METALLURGIST types" but we know what you mean.
Anyway the problem with Spi pole ends in never ending and will remain so while the manufacturers continue to have a sliding "piston" running in a cast aluminium housing. It is a little complex....

[/ QUOTE ]
I wonder if you have put your finger on something for me... galvanic corrosion requires an electrolyte. Pure water is not an electrolyte, but seawater is a v good one. Rainwater is not pure water, but tapwater is a poor electrolyte, I understand, due to treatment and chlorine. So JJ may have made a good point, and each time after sailing, push water through the piston/housing to get all the lovely strong electrolyte out, as well as any salt which may be building up and making things worse - replacing it with a weaker electrolyte - tapwater !! That's it for me this year, let you know what happens.