Copper Grease or Not?

[Stemar]

One of my jobs in the next few weeks is to replace the mild steel bolts on my Mariner outboard with stainless ones. From the weight of the thing, you'd think they were going into lead, but I'm guessing it's aluminium. Since I'd quite like to be able to shift them a year or two down the line, I'm thinking about a bit of copper grease, but would introducing another metal into the electrolytic equation be a bad idea?

The alternative would be to douse each one in ACF50.

 

[simonfraser]

depends how wet they get, use waterproof grease ?
recon the ACF or copper may wash out ?

 

[Praxinoscope]

Isn't this what Duralac is for?

 

[JFowler]

Or Tef-Gel.

 

[Praxinoscope]

Or Tef-Gel.

Haven't tried this yet, is it as messy as Duralac?

 

[RichardS]

In your application I would use aluminium grease rather than copper grease but either is far better that nothing.

Richard

 

[Norman_E]

Isn't this what Duralac is for?

If you ever want to get the bolts out again use Duralac.

 

[TernVI]

Sometimes it's actually better not to use stainless.
Zinc plated screws, each one covered with their own anode?
Whereas stainless is a fairly aggressive cathode once you scratch the surface.
Any grease will do.
Copper grease has been used with great success by millions of mechanics.
Other metal-grease patent gunges may be a bit better.
Duralac is not intended for lubricating threads.
Tefgel is just an expensive thin grease with a bit of ptfe in.

 

[Charlie Boy]

Steve66 sells ss bolts for the Honda 2.3. Why not ask him? The body will be alloy too, I guess.

 

[Daydream believer]

Stockholm tar?

 

[Gary Fox]

Lanolin works for me, in particular on the Aries windvane, which has lots of SS fasteners into aluminium alloy castings.
Plaster it all over the place, wonderful stuff. It is not a lubricant though.

 

[VicS]

One of my jobs in the next few weeks is to replace the mild steel bolts on my Mariner outboard with stainless ones. From the weight of the thing, you'd think they were going into lead, but I'm guessing it's aluminium. Since I'd quite like to be able to shift them a year or two down the line, I'm thinking about a bit of copper grease, but would introducing another metal into the electrolytic equation be a bad idea?

The alternative would be to douse each one in ACF50.

Use the same water resistant grease that you are using for the greasing points generally on the engine.

Quicksilver 2-4-C, a lithium grease containing ptfe, if you are using the Mercury/Mariner recommended grease.

I use Ramonol White grease for my Evinrude which has all stainless steel bolts anyway.

 

[ghostlymoron]

We used lanolin hand cream when fitting the holding down bolts on some equipment at a sewage treatment plant. They were 300mm x 25 and there were hundreds of them, it's unlikely that they'll ever be rem all set to the required oved but the risk was that they would seize up when part installed known as 'galling' this had happened a couple of time before the expert was called.
It was our metallurgist that recommended Boots hand cream which contains a high amount of lanolin - we cleaned out the local store and our hands were sooo soft. The bolts all set to the required torque with no further problems.

 

[Poey50]

Windpilot use Lanocote for protecting the stainless steel fixings in contact with aluminium on their wind vanes so know a thing or two about corrosion resistance in extreme conditions. It's much less messy than Duralac and smells pleasantly of sheep.

 

[RJJ]

Windpilot use Lanocote for protecting the stainless steel fixings in contact with aluminium on their wind vanes so know a thing or two about corrosion resistance in extreme conditions. It's much less messy than Duralac and smells pleasantly of sheep.

I like lanolin. It's cheap as well as sheep.

Is there much meaningful difference, for our purposes, between lanocote and lanolin?

 

[Poey50]

Lanocote isn't cheap but it has that kind of sticky greasyness that feels like it will never wash away. It's too thick to be messy. It's nearly solid in the pot.

 

[thinwater]

Marine antiseize does not contain copper, because yes, galvanic corrosion is a problem. I have tested this.

It does not strictly apply to inboards, which don't see seawater.

Many good suggestions for the outboard. However, many of these will not stand the heat for engine block applications. So it depends on where they are going.

 

[Gary Fox]

Lanocote isn't cheap but it has that kind of sticky greasyness that feels like it will never wash away. It's too thick to be messy. It's nearly solid in the pot.

That describes anhydrous lanolin, which has had any water and bits of sheep removed. Not arguing but I think Lanocote is A/L with added 'Yacht Tax'

 

[Topcat47]

Copper and Stainless are not a good mix. Some grades suffer badly from inter-granular penetration by the copper in the grease which affects the structural integrity of the bolts after time, some less so but when I worked on Reactor systems in the 70's We weren't allowed to use our own tools in case we'd had them in contact with copper, brass or bronze.

 

[Bilgediver]

Copper and Stainless are not a good mix. Some grades suffer badly from inter-granular penetration by the copper in the grease which affects the structural integrity of the bolts after time, some less so but when I worked on Reactor systems in the 70's We weren't allowed to use our own tools in case we'd had them in contact with copper, brass or bronze.

.

I agree and for this reason it isn't a good idea to mix copper filled greases with stainless that is in a stressed location. I think ordinary grease would be fine. Try and minimalist the variety of materials in contact.