anorton wrote:

"Christopher Tidy" wrote in message
...
Gunner Asch wrote:

If its not dynamically loaded..should work fine. If its loaded...it
wont
last as long as other better Stuff will.

Thanks for the thoughts. It's a piston in a miniature air pump.
Here's a picture. The plastic layer is over the knurling you can see:
http://www.mythic-beasts.com/~cdt22/pump_piston.jpg

I had wondered about oil-filled nylon. It's definitely not epoxy as
I've been told it was thermally moulded.

Chris


It is too clear to be filled with anything. It could be nylon,
polycarbonate or even low density polyethylene. If you can do
destructive testing, strong acids will eat nylon, and ketones
(lacquer thinner) will eat polycarbonate. Polyethylene will be more
resistant to both, but it is not compatible with mineral oil.
There are some easier tests for basic plastic types and more detail can
probably be found on the net. 3 of the basic ones I remember are nylon
when burned smells like burning hair, polypropylene and polyethylene
smell like a burning candle but one floats in water though I can't
remember which one, it'll be the less dense one anyway. There are a
number of other simple tests like these to help narrow down the basic
stuff.