Stainless bolts in ally

[Jabs]

Can someone remind me of the name for the compound used to insulate stainless screws, bolts, etc when used in alloy spars?

It reduces the risk of corrosion.

Need to buy some more and the boat is overseas.

Thanks

Tony

 

[TernVI]

Duralac is the semi-hardening paste.
Copper grease, nevr seize (sp?) etc are alternatives for bolts
A thread locking compound also does the job.

Duralac used to be a 'chromate paste'? Must other brand names, and I'm not sure it's got chromate in it these days?

 

[andsarkit]

Duralac
(beaten to it by Tern VI)

 

[Poignard]

:: Llewellyn Ryland :: Bringing Colour To Life ::

 

[VicS]

Can someone remind me of the name for the compound used to insulate stainless screws, bolts, etc when used in alloy spars?
It reduces the risk of corrosion.
Need to buy some more and the boat is overseas.
Thanks

Tony

Duralac , as said It is a barium chromate paste
There is now a chromate free alternative ... Duralac Green .... http://www.sanshin.co.uk/Pdfs/DuralacGreen.pdf

A less messy alternative for close fitting joints is Tef-Gel which is Teflon based

Presumably when you say "alloy" spars you mean aluminium alloy.
Not sure about the wisdom of using a copper based anti-seize grease on aluminium.

 

[Pye_End]

Tef Gel

 

[TernVI]

Tef Gel

That's just very expensive grease.

 

[KompetentKrew]

Not sure about the wisdom of using a copper based anti-seize grease on aluminium.

Coppaslip is very commonly used between steel and aluminium by motorcycle mechanics.

I'm sure others have posted here (@rotrax?) saying they've been using it on their boats for years. The french mechanic who serviced my outboard applied it liberally.

 

[vic008]

Tefgel here.Duralac dries in the tin amd gets thrown out

 

[Rappey]

I've never seen duralac in a tin, only in thin aluminium tubes that are easy to split.
A tube does appear to keep forever but it separates so you end up with lots of dark goo that's hard to mix back in. But it does seem to do its job.

 

[MM5AHO]

Its seems to me also a bad idea to use copper containing grease on aluminium alloys. (Even if common practice)

 

[penberth3]

Its seems to me also a bad idea to use copper containing grease on aluminium alloys. (Even if common practice)

This point keeps coming up, its in Post #6 above, but is it really a problem? The copper flakes are in grease which must limit the conductivity, it isn't the same as metal to metal.
It has become common in the motor trade, it gets used everywhere nowadays whether its the right product for the job or not.

 

[TernVI]

Its seems to me also a bad idea to use copper containing grease on aluminium alloys. (Even if common practice)

It's a great idea, because it works.
I freely admit to not knowing how or why, but it does.

 

[PetiteFleur]

I've used Duralac in the past but as mentioned it does separate - I've also used grease which seems to work.

 

[RichardS]

This point keeps coming up, its in Post #6 above, but is it really a problem? The copper flakes are in grease which must limit the conductivity, it isn't the same as metal to metal.
It has become common in the motor trade, it gets used everywhere nowadays whether its the right product for the job or not.

Indeed. We have been discussing this same issue on here for about 10 years whereas I've been using copper grease on steel into ally bolts without a problem for about 50 years.


Richard

 

[cherod]

Tefgel here.Duralac dries in the tin amd gets thrown out

only if you dont use it , mine is in a tube .

 

[lynallbel]

Its seems to me also a bad idea to use copper containing grease on aluminium alloys. (Even if common practice)

At work we have been told to stop using it, as they reckon it can casue corrosion between the wheel and the hub.
I use an alloy anti seize paste, 10 quid a tin, very good.

 

[Iliade]

We used to use molybdenum disulphide grease on brass/copper/aluminium gas fittings. It doesn't set like Duralac, but probably isn't quite as good at keeping the metals apart.
Easily identified in use because it is very black, gets everywhere and is very hard to clean off.

A little googling shows it to be subject to marine, diy and trade pricing structures ? though that may have something to do with the moly/grease ratio supplied:

Park Tool Anti-Seize Compound ASC-1 112g/ 4oz Lube£9.99wiggle.co.uk(105)For most items:365-day return policy
PRICE DROPSealey - SCS103 Aluminium Anti-Seize Compound 500g Tin£5.57Was £8ToolBayUK
Rocol Anti-Seize Compound 500g£21.59Industrial Outlet

 

[RichardS]

At work we have been told to stop using it, as they reckon it can casue corrosion between the wheel and the hub.
I use an alloy anti seize paste, 10 quid a tin, very good.

For the last few years I've actually switched from copper grease to ally grease on wheels and hubs but only because it looks cleaner than copper grease. I've never had any problems with copper grease.

Richard

 

[Rappey]

I've seen a few articles over the years that suggest the only reason some mechanics use copper grease nowadays is because they are old school and out of touch with modern times.