Stainless Exhaust Studs. How to hold 'em in?

[Ginger Bear]

I picked up some stainless exhaust studs from Exhaustcraft while I was at Stafford.
Now I'm not sure if it's best to fit them (into the head) with with some copper grease, so they can be removed or coat them with thread lock for a more permanent fixing.

Gentlemen, your thoughts would be appreciated.

[KWACKERZ1]

Personally copper slip, once tight they should be fine.

Thread lock them and heaven forbid if you cross thread one bend one etc it'll be a bugger to get out.

just my humble opinion

[jimmock]

I WOULD NEVER go near thread lock EVER, but esepecially in a head!!!

I've changed a few header studs to stainless over the years.
IT IS THE WAY FORWARD.

I lube the threads and lock nut them up right into the hole until it bottoms out on the SHOULDER, not the hole bottom.

Remove the lock nuts and hey presto stud locked into head.

The friction between the ex nut and stud will always be less than the friction between the stud and head and thus the nuts will always come off rather than winding the stud back out. ASSUMING OF COURSE NO DAMAGED THREAD ON STUD OR NUT.

[750steve]

Copper grease to put them into the head

Use copper nuts to hold the exhaust flanges on, they don't seize up

[750steve]

I WOULD NEVER go near thread lock EVER, but esepecially in a head!!!

Not even on brake disc bolts?

[kev edwards]

Copper grease them i guess you got stainless nuts as well.

[steve bowdler]

you got stainless nuts as well.

Thats a bit outright

[KeithZ1R]

use rocol molybdenum disulphide paste and you will never have any trouble ever

[hillbilly]

Personally.i wouldnt put stainless steel bolts in.as its not one of the best pair of metal to pair up.use normal metal ones.lot easier to get out if owt goes wrong.

[Pigford]

Personally.i wouldnt put stainless steel bolts in.as its not one of the best pair of metal to pair up.use normal metal ones.lot easier to get out if owt goes wrong.

And Copper Slip is only of use for certain metal combinations - couldn't say what the are though

Threadlock probably won't work too well on the exhaust studs, as It'll just burn off

[jimmock]

I WOULD NEVER go near thread lock EVER, but esepecially in a head!!!

Not even on brake disc bolts?

NOT even on disc bolts.

Never had an issue with disc bolts coming out with spring washers??

[Steve Cooke]

I used copper grease on mine and I've had no problems.

[Rich]

use brass nuts

[LondonZ1]

I use copaslip and have always found it excellent. Incidentally Rocol's copaslip equivalent is called Anti-seize compound which is a "copper based anti-seize paste reinforced with graphite and molybdenum disulphide". The data sheet goes on to list exhausts as a typical application.

On my bike I will be using stainless studs with copaslip and then stainless aerotight nuts.

[Mark Stratton]

Lifted from INOX Fasteners website;

Why is it really that important to use copper anti seize and not something else?
When stainless steel is fastened ‘dry’ into Aluminium, galvanic corrosion can occur as the result of two different materials at opposite ends of the ‘metal nobility’ table being interfaced. In practical terms this means that alloy crankcases can oxidise around the fastener area very quickly. Copper based anti seize provides a third metal as the ‘sandwich’ and, as copper is placed in the centre of the ‘metal nobility’ table, it prevents Galvanic corrosion. Ordinary grease or oil will not work as they do not contain the vital element. UNDER NO CIRCUMSTANCES use Aluminium grease of any sort - including aerosols - as it will probably seriously damage the castings.



I've always used copperslip on all my stainless fasteners and never had a problem.