One for the chemistry majors

[markbt73]

Why doesn't anaerobic thread-lock dry out in the tin? Anaerobic means it should cure when it's not exposed to air. Tin's closed, so no air...

[loco_oso]

Not a chem major, but is there still air in the tin, above where the thread-lock is?

[TWINSET]

And the tin's probably not 100% airtight

Also, is it oxygen that keeps it liquid, or does it use oxygen to keep it liquid - Maybe the presence of oxygen is all it needs to not dry out?

[WillyChang]

I use loctite gelstick

it seems to cure only under pressure of 2 metal surfaces

where it goes hard and brittle at the threads whilst

any excess at the tip of screw stays gel

I've left the tube open on desk most of last week too

under hot window... the gel has softened and flowed

a little but none cured. Even the spillover that's

squished between cap and tube stays smearable,

not cured - simply wipes off.

Interesting compound eh? No wonder it's so expensive

[bromvw]

ok this is far from a definitive reply but as i understand it from a engineering standpoint it means that the gel will only set in the absence of air . ie close fitting 'airtight' parts . Pressure may have something to do with the process but thats something begond my understanding .

[markbt73]

I figured pressure must have something to do with it. Just a weird thought that popped into my sleep-deprived brain last night...

[IBIFTKH]

Being able to spell 'anaerobic' whilst sleep-deprived is an achievement in itself

[WillyChang]

http://www.henkel.com/us/content_data/1015...ing_Article.pdf

according to loctite, it needs proximity to metal ions before it will polymerise.

Oxygen hinders the process so bottle has head of air.

Locking is achieved via molecular contact of 100% between the 2 metal surfaces

sandwiching the glue; if the metal surfaces were raw polished alone

might only be 15% touching.

No mention of dissimilar metals but mine seems to cure faster on cars using

black oxide hi-tensile screws rather than 302/304 Stainless or Ti.