Aluminium / Stainless seizure

Mike 40M

Well Known and Active Forum User
VOC Member
It is often mentioned that stainless screws in alloy cases is no good. Still there is a lot of them for sale. I happened to see that Loctite 8009 should be a solution to the problem. Anyone with experience of that stuff, or any other gunk to use?
 

oexing

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VOC Member
That Loctite type should be great but you could get any copper or MoS2 Molycote grease for better price and no problem with these on stainless fasteners. Aluminium is not so much of a problem for stainless but stainless bolts in stainless nuts is critical as no plating is there like zinc or cadmium on standard fasteners. The plating acts as lubricant so that is the reason why stainless requires some extra lubricant in ALL cases. In places where you don´t like some grease an application of Loctite acts as lubricant so you don´t get seizure within the threads.
I use stailess on my bikes for many decades , no troubles , never. Helicoil had huge global success with their coil thread repair sets for spark plug thread as most drivers do not lubricate plugs for alu heads so they get "friction welding" within the threads without lubrication.

Vic
 

davidd

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VOC Member
I have been using Loctite LB 8060 for about a decade. It is primarily graphite. It is a stick and you can run it around the threads. I have also used the thread locker in stick form and have had good results, but I lockwire almost everything. They make a copper based anti seize in stick form also.

A friend was rebuilding a D and turned the OP 33, which is aluminum, into the oil pump. It galled and when he tried to back it out the case cracked. Not the kind of thing you want to happen. I tend to use anti seize rather liberally because I like the lighter aluminum parts on the racer.
26092

Recently, a SS RFM pivot came out of a street bike very hard. It had corroded in a way that looked like surface to surface interaction. I would use some type of coating on a part like that with a lot of surface area. I have Tef-Gel in the shop, but you may have to take a loan to purchase it. It has an exceptional reputation in the marine industry.



David
 

Oldhaven

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VOC Member
When working with SS fasteners in my aluminum boat I apply Permatex Nickel anti-seize lubricant, (#77124), especially for things like nutserts. It is recommended for stainless, titanium, and nickel alloy fasteners. I have been wary of the use normal copper anti-seize because of bimetallic corrosion with the aluminum/SS combination, especially in a marine environment, but perhaps I need not worry. Certainly there are a lot of brass fittings in aluminum threads on a Vincent
 

john998

Well Known and Active Forum User
VOC Member
Electrolytic corrosion between aluminium and stainless steel is a problem.
The rear mudguard hinge pivot is particularly prone. In the north sea oil industry the only product then available then that worked was PBC grease.
The ordinary copper grease was worse useless.
As far as engine cover screws go, I have not had any problems, probably plenty of oil about. John.
 

Simon Dinsdale

VOC Machine Registrar
VOC Member
VOC Forum Moderator
Usually electrolytic corrosion requires an electrical current to be passing through to cause corrosion , hence the problem with the rear mudguard hinge pivots which is the electrical return path for the rear / brake light.

Even static electricity conduction can be a problem on boats, oil rigs etc along with the constant presence of salt water. Probably not a big problem for most Vincents today.
 

macvette

Well Known and Active Forum User
Non-VOC Member
Usually electrolytic corrosion requires an electrical current to be passing through to cause corrosion , hence the problem with the rear mudguard hinge pivots which is the electrical return path for the rear / brake light.

Even static electricity conduction can be a problem on boats, oil rigs etc along with the constant presence of salt water. Probably not a big problem for most Vincents today.
You do not need an imposed electric current to cause corrosion. Any electrolyte e.g. Water with some salt between two dissisimilar metals will generate its own current and cause corrosion.
 
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