Re: drain plug washer reuse

[raf40@oes.amdahl.com (Richard Funnell)]

It's been a while since I studied this stuff, but I thought that annealing
required a slow cooling cycle, as opposed to dunking in water.  I would
also be concerned about the distortion which occurs when the plug is
tightened, which is not addressed by annealing.

Another approach is to buy the drain valve from Imparts, and avoid the
problem altogether.  This was discussed many months ago with several
listers reporting good experience.  Based on that experience, I have
installed such a valve with no leaks so far.

>After reading the debate about changing the copper washer on the drain plug
>at each oil change I thought I would pass along what I do.
>
>The reason the copper washer looses its sealing capacity for a given torque
>on the drain plug is that it gets work hardened by being crushed.  All you
>need to do to restore it to its original soft, easy sealing state is to anneal
>it by heating it to cherry red and quenching it in water.  I do this by
>dangling the washer on a wire coat hanger in the flame of the gas stove, then
>dunk it in a pan of cold water (what else are all those things in the kitchen
>for?).
>
>Of course, it does get thinner and flatter every time you use it, so you can't
>do this for ever or you end up with copper foil, but it doesn't take much to
>seal.
>
>Paul

Richard Funnell,
San Jose, California
'83 urQ
'87 560 SL