<VV> VV> Metal question, not necessarily Corvair

[Dale Dewald]

At 21:20 8/10/2008 -0400, Marc Sheridan wrote:

 >>snip<<
>My bicycle has an aluminum seat post in a steel seat tube. While looking for a
>creaking noise, I discovered that I forgot to use anti-seize in this
>situation, because the seat post won't budge
>
>Has anyone found a way or a chemical that will break that bond? I've been
>shooting PB Blaster on it everyday for weeks and it still won't move. Heat
>is out of the question because it would ruin the paint and I can still ride
>it the way it is. I'd just like to get it freed in case I do want to adjust
>it for some reason.

You may want to try cold.  Since aluminum has a greater thermal expansion 
coefficient it will shrink more than the steel tube when chilled.

Maybe you could try a can of circuit cooler from an electronics supply 
house, but this might not get it cold enough. However, the ideal chill 
could be made with liquid nitrogen.  Maybe you could get the left over LN2 
from your doctor's office at the end of the day when they have it available 
to freeze warts.

If you get some, make a dish or cup like mold out of styrofoam to contain 
the LN2 around the seat post.  LN2 will boil and spatter on contact with 
anything warm. Wear heavy gloves and eye protection [goggles].  LN2 on the 
skin causes almost instant frostbite burns--painful, but will heal. LN2 in 
the eyes will cause permanent damage.

If you end up trying this, please let us know how it works out.

Dale Dewald
Hancock, MI