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Old 19 April 2010, 16:26   #11
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Conductive as in electrical . My tilt rams are sitting in ATF oil and are not being earthed because of the oil and rubber O-rings therefore they are being pitted because of electrolysis . If i can find the right oil it means the rams are earthed because of the bonding on the engine and clamp bracket . All anodes are working properly with the bonding circuit but because of no earth on tilt rams the stainless is pitting
There is no oil that 'conducts' electricity IMO. Do you know for a fact your rams are stainless ? and perhaps arent coated with teflon or chrome which is wearing off, exibiting the 'pitting' you mention.

Sacreficial annodes would in normal circumstances prevent corrosion, but only if they are in good condition, and all parts are earthed, and you havent painted over them

In most cases, the structure of a hydraulic ram does not lend its self to the rod being completely isolated from the cylinder, commonly, the seal pack at the base will be in contact with the cyliner, even though sealing rings prevent oil seepage. And if this is not the case, and your ram is isolated, how would a current be getting generated then, to cause the corrosion on the rod if its isolated ?
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Old 19 April 2010, 16:28   #12
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That would make more sense than the tilt rams I suppose.
Like you say, simple solution leave it down! unless its somewhere that dries.
i am sure with a little ingenuity you could make a small springy brush to rub on the ram to earth it.
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Old 19 April 2010, 16:34   #13
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There is no oil that 'conducts' electricity IMO. Do you know for a fact your rams are stainless ? and perhaps arent coated with teflon or chrome which is wearing off, exibiting the 'pitting' you mention.

Sacreficial annodes would in normal circumstances prevent corrosion, but only if they are in good condition, and all parts are earthed, and you havent painted over them

In most cases, the structure of a hydraulic ram does not lend its self to the rod being completely isolated from the cylinder, commonly, the seal pack at the base will be in contact with the cyliner, even though sealing rings prevent oil seepage. And if this is not the case, and your ram is isolated, how would a current be getting generated then, to cause the corrosion on the rod if its isolated ?

all good and valid points, however dont forget that all steels will have a certain degere of non uniformity in the metallurgy, leading to some parts being less electro-negative than others, so it is possible for a plain steel bar to have local galvanic cells leading to deep local pitting, unless an anode is fitted so that whole area relatively becomes cathodic to the anode.
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Old 19 April 2010, 18:46   #14
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I'm afraid to fit an anode strap as maybe the point of contact from the strap might then become the weak point . Also when i trim down i might shear off the strap . I am hoping that it is poor quality rams , but they have been replaced twice already . Had a closer look again tonight and found it is only one ram at this stage that has pitted . Previously it was both . Someone has suggested that i canget a conductive rubber so in that case i could get the O-Rings changed ? Rams are setting me back about 150 apiece , any ideas where i could get a better deal ?
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Old 20 April 2010, 01:48   #15
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I'm afraid to fit an anode strap as maybe the point of contact from the strap might then become the weak point . Also when i trim down i might shear off the strap . I am hoping that it is poor quality rams , but they have been replaced twice already . Had a closer look again tonight and found it is only one ram at this stage that has pitted . Previously it was both . Someone has suggested that i canget a conductive rubber so in that case i could get the O-Rings changed ? Rams are setting me back about 150 apiece , any ideas where i could get a better deal ?
A pic might help a bit more .. does it sit in salt water, that has a fresh water input nearby ? .. like a marina with a burn running into it

What make is the leg ?
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Old 20 April 2010, 04:18   #16
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I'm afraid to fit an anode strap as maybe the point of contact from the strap might then become the weak point . Also when i trim down i might shear off the strap . I am hoping that it is poor quality rams , but they have been replaced twice already . Had a closer look again tonight and found it is only one ram at this stage that has pitted . Previously it was both . Someone has suggested that i canget a conductive rubber so in that case i could get the O-Rings changed ? Rams are setting me back about 150 apiece , any ideas where i could get a better deal ?

Use stainless earth straps from any of the outboard motor manufacturers, and stainless screws, then they shouldn't be a problem.

Or the alternative that no one seems to have suggested, certainly on my Yamaha this works, If you tilt fully up, engage the tilt lock, then try to tilt back down, the engine will tilt down onto the tilt lock, then fully retract the trim rams, before the PRV in the hydraulic pump operates. if you leave it like that then only the tilt rams are exposed, and an earth strap across the eye of one of them should be a simple job.
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Old 20 April 2010, 14:44   #17
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Trim Rams Again

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I suspect it's the trim rams that are the problem-with the engine tilted up there's no electrical contact to them so they won't get any protection from the anode.
I'm hoping this is the case . Will earthing the rams correct the problem ? I can get conductive rubber O-Rings and a glycol and water based fluid instead of the ATF
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Old 20 April 2010, 14:57   #18
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I'm hoping this is the case . Will earthing the rams correct the problem ? I can get conductive rubber O-Rings and a glycol and water based fluid instead of the ATF
so can you retract the trim rams as in my above post?
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Old 20 April 2010, 17:44   #19
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Yes i can retract the trim rams . But i will have very little contact with an earth strap loop on the rams . I am afraid that this will only concentrate the pitting to the area of contact . I am hoping to fit conductive rubber O-Rings that will carry the earth bonding from the clamp bracket and tilt assembly casing to the ram . I am also going to drain ATF and replace with glycol and water solution which is for extra protection . I am nearly convinced at this stage that it is the ram quality cos only one of two is pitted . Engine is Suzuki but Yamaha have the same dimension ram . How could i source a cheap replacement Yamaha ram ?
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Old 20 April 2010, 17:47   #20
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I am also going to drain ATF and replace with glycol and water solution which is for extra protection .
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