Anti-seizing compounds

[stevenal]

Both

http://www.bostik-us.com/TDS/TDSFiles/NSMarinersChoice.pdf

and

http://www.bostik-us.com/TDS/TDSFiles/NSMarineGrade.pdf

claim to inhibit or prevent galvanic corrosion. By excluding the electrolyte from the joint? If that's the case, why the metals in the suspensions. And the graphite is at the extreme end of the galvanic scale. Do the metals help in some way, or would a non-metallic (Teflon for example) based anti-seize make more sense in marine applications?

 

[MikeHalloran]

The metal and/or graphite in anti-seize is there to lubricate the threads under the extreme pressure of preloading the joint. The binder/ carrier/ oil/ grease/ whatever incidentally excludes the electrolyte.

Teflon is not a great lubricant at high pressures; it just oozes out of the threads.

That said, I, personally, often use Loctite PST (r) on marine threads, because it's a mildly effective lubricant _and_ a pretty decent threadlocker, _and_ it excludes the electrolyte. On a really high stress joint, I might mix in a little metallic anti-seize.



Mike Halloran
Pembroke Pines, FL, USA

 

[IRstuff]

Teflon exhibits "cold flow." This is good and bad, since a little cold flow allows Teflon to act as both lubricant and sealer, but too much cold flow and you've got squat.

TTFN

FAQ731-376

 

[johnSchwaner]

Possibly this report might help. It's about dry film instead of antiseize but something to think about.


"...shown conclusively that graphite in a resin-bonded solid film lubricant is deleterious from the point of view of corrosion protection proviced by the lubricant... To use graphite is to invite corrosion difficulties in the presence of moisture."

Rock Island Arsenal Labratory, Technical Report, Dry Lubricants and Corrosion, Prepared for Presentation at the Annual Meeting of the Society of Automotive Engineers, Detroit, Michigan 14-18 January 1963. Francis S. Meade and George P. Murphy, Jr.

John Schwaner

http://www.mechanicsupport.com