Copper grease with stainless steel and aluminium?

[wully1]

The stainless steel pistons on the ends of my whisker pole fur up and jam with white, crumbly paste. I’ve stripped and cleaned the piston pins, springs and the holes they slide in.

I have some of the insulating paste used to mount stainless steel fittings which will be too thick to use for this - or some copper grease which will work.

The question is - will the copper grease make the corrosion worse or is it safe to use?

 

[Shearmyste]

copper grease should never be used on Ali as the reaction between the two will leave holes (I own an Ali boat), the white deposits could be corrosion or salt, I have used a light oil in the past but i found regular cleaning with boiling water works best.

 

[RichardS]

I've been using copper grease on steel nuts, bolts and studs through aluminium fittings for the last 50 years without a single problem.

However, if you have any concerms you can buy aluminium grease. I tend to use the aluminium variety on alloy wheel studs as any overspill looks more attractive.

Richard

 

[lw395]

I've been using copper grease on steel nuts, bolts and studs through aluminium fittings for the last 50 years without a single problem.

However, if you have any concerms you can buy aluminium grease. I tend to use the aluminium variety on alloy wheel studs as any overspill looks more attractive.

Richard

Same here.
Copper grease is standard for putting stainless bolts into bits of motorbike.

But it is messy. It will leave black stains on clothes, sails, crew.
For this sort of thing I use a clear grease or oil with PTFE in it.
But if you don't want dobs of grease getting on stuff, the best thing is little and often.
Even clear grease will pick up black from the metals.

The point about cleaning with hot/boiling water is good.

 

[Ric]

There is - of course - a special product for this sort of thing. It is clear and does not stain. I have some at home but can't remember its name...

 

[macd]

There is - of course - a special product for this sort of thing. It is clear and does not stain. I have some at home but can't remember its name...

Tef-Gel?

 

[wully1]

Thanks guys.

Next time I’m in the big, bad city I’ll check out the car accessory shops for some alloy wheel nut grease.

 

[thinwater]

Copper is used in some anti-seize formulations to prevent galling in high temperature applications where the organic portion of the grease will be cooked out. It serves NO function at ordinary temperatures (I've done the research both in the lab and field). Second, marine anti-seize products, from the same companies, do NOT contain aluminum or copper. It is well know that even in grease, copper increases galvanic corrosion. Sure, you may no notice, since the effect is small, but copper never helps a marine grease. There is simply no chemistry to support that assertion.

All the OP needs is a good water proof grease. Lewmar Winch Grease, for example, would be an excellent choice, since only a dab is needed.

 

[MM5AHO]

Copper is used in some anti-seize formulations to prevent galling in high temperature applications where the organic portion of the grease will be cooked out. It serves NO function at ordinary temperatures (I've done the research both in the lab and field). Second, marine anti-seize products, from the same companies, do NOT contain aluminum or copper. It is well know that even in grease, copper increases galvanic corrosion. Sure, you may no notice, since the effect is small, but copper never helps a marine grease. There is simply no chemistry to support that assertion.

All the OP needs is a good water proof grease. Lewmar Winch Grease, for example, would be an excellent choice, since only a dab is needed.

+1

 

[RichardS]

Copper is used in some anti-seize formulations to prevent galling in high temperature applications where the organic portion of the grease will be cooked out. It serves NO function at ordinary temperatures (I've done the research both in the lab and field). Second, marine anti-seize products, from the same companies, do NOT contain aluminum or copper. It is well know that even in grease, copper increases galvanic corrosion. Sure, you may no notice, since the effect is small, but copper never helps a marine grease. There is simply no chemistry to support that assertion.

All the OP needs is a good water proof grease. Lewmar Winch Grease, for example, would be an excellent choice, since only a dab is needed.

No difference of opinion about underwater marine applications or the OP's particular situation where I would use waterproof calcium grease ..... however if your research was in the auto field it is not the whole story as ordinary grease will dry out at ambient temperatures over a few years and much quicker at the modest temperatures reached by wheel studs etc where heat is always transmitted from the brake discs / drums / engine.

You are always better off using copper/ally grease for anti-seize applications as even when the substrate has dried away, the metal content will still provide a lubrication function.

Richard

 

[penberth3]

Copper is used in some anti-seize formulations to prevent galling in high temperature applications where the organic portion of the grease will be cooked out. It serves NO function at ordinary temperatures...

Unfortunately, over the last few years the UK motor trade have started using cooper grease everywhere! No idea how this fashion started.

 

[RichardS]

Unfortunately, over the last few years the UK motor trade have started using cooper grease everywhere! No idea how this fashion started.

And they are absolutely correct in doing so .... although it has taken the motor trade 50 years to catch up with DIY engineers like me. See post #10.

Richard

 

[lw395]

Unfortunately, over the last few years the UK motor trade have started using cooper grease everywhere! No idea how this fashion started.

Probably a lot of them have been faced with steel bolts that won't come out of alloy parts, because they weren't greased.

 

[macd]

Unfortunately, over the last few years the UK motor trade have started using cooper grease everywhere! No idea how this fashion started.

We had a replacement cooling matrix installed on our six year-old UK car in Greece last year at a specialist air-con garage. They'd done several identical jobs on similar cars, but such was the state of the metal fasteners that ours took three times as long as local cars to take to bits. (I watched them, and it was a struggle.) Maybe that's the reason.

 

[thinwater]

No difference of opinion about underwater marine applications or the OP's particular situation where I would use waterproof calcium grease ..... however if your research was in the auto field it is not the whole story as ordinary grease will dry out at ambient temperatures over a few years and much quicker at the modest temperatures reached by wheel studs etc where heat is always transmitted from the brake discs / drums / engine.

You are always better off using copper/ally grease for anti-seize applications as even when the substrate has dried away, the metal content will still provide a lubrication function.

Richard

Me and the world of grease formulators are simple going to agree to disagree with you:

http://na.henkel-adhesives.com/product-search-1554.htm?nodeid=8797882515457
http://www.loctite.com.au/3320_AUE_HTML.htm?nodeid=8802636201985

Particularly when one of the metals is aluminum, adding copper will make things worse by increasing galvanic corrosion of aluminum and white white powder that is causing the OP's sticking. This is obvious and suported by testing. It will not provide lubrication for aluminum. Additionally, good quality synthetic greases like Lewmar or Tefgel do not dry out at room temperature for many decades. In fact, one of the defining characteristics of synthetics is extremely low volatility and high oxidation resistance.

Finally, the OP is talking about sliding parts, not fasteners on an exhaust manifold. Totally different application.

Some testing from Practical Sailor. This is about conductive greases, but the point is the same.
https://www.practical-sailor.com/issues/37_76/features/Conductive-Greases-vs-Corrosion_12188-1.html

 

[RichardS]

Me and the world of grease formulators are simple going to agree to disagree with you:

http://na.henkel-adhesives.com/product-search-1554.htm?nodeid=8797882515457
http://www.loctite.com.au/3320_AUE_HTML.htm?nodeid=8802636201985

Particularly when one of the metals is aluminum, adding copper will make things worse by increasing galvanic corrosion of aluminum and white white powder that is causing the OP's sticking. This is obvious and suported by testing. It will not provide lubrication for aluminum. Additionally, good quality synthetic greases like Lewmar or Tefgel do not dry out at room temperature for many decades. In fact, one of the defining characteristics of synthetics is extremely low volatility and high oxidation resistance.

Finally, the OP is talking about sliding parts, not fasteners on an exhaust manifold. Totally different application.

Some testing from Practical Sailor. This is about conductive greases, but the point is the same.
https://www.practical-sailor.com/issues/37_76/features/Conductive-Greases-vs-Corrosion_12188-1.html

Errrrr ..... nope. Nothing there that disagrees with anything I've said, I'm afraid.

As for "sliding parts" and marine applications ..... what is it about "No difference of opinion about underwater marine applications or the OP's particular situation where I would use waterproof calcium grease" that you are not grasping?

Which means that it's only you who is disagreeing with me ..... and now with several other forumites above.

Richard

 

[Lon nan Gruagach]

Same here.
Copper grease is standard for putting stainless bolts into bits of motorbike.

But it is messy. It will leave black stains on clothes, sails, crew.
For this sort of thing I use a clear grease or oil with PTFE in it.
But if you don't want dobs of grease getting on stuff, the best thing is little and often.
Even clear grease will pick up black from the metals.

The point about cleaning with hot/boiling water is good.

How relevant is motorcycle engineering though? How often would you fit an anode to a bike to stop it rotting?

 

[RichardS]

How relevant is motorcycle engineering though? How often would you fit an anode to a bike to stop it rotting?

But we're discussing the general admonishment in post #2 "copper grease should never be used on Ali" so any and all relevant commentary is to be welcomed.

Richard

 

[Normalfornorfolk]

I reckon Tefgel is what you are after.
Use it sparingly, it's very sticky and gets everywhere if you overdo it but as a ss/alloy interface it is brilliant.

 

[penberth3]

And they are absolutely correct in doing so .... although it has taken the motor trade 50 years to catch up with DIY engineers like me. See post #10.

Richard

It's not correct to be smearing copper grease on hinges, bonnet catches etc. This is what I'm seeing.