On 30 Aug 2005 21:26:55 -0700, Too_Many_Tools wrote:
A used surface plate just showed up on my doorstep...amazing what
follows me home sometimes. :)

I thought it was just me who has that problem.

This surface plate is a Rahn 34" x 36" black granite with two ledges.
So, how does one decide if a surface plate is "good"?

Naah, it's junk. Send it to me and I'll dispose of it for you, without
even charging you.

If it is "bad", how do you decide whether or not it is worth
refurbishing? How much does it cost to refurbish a surface plate and
how do they do it?

I would _think_ that, being granite, it probably won't have "much" wear.
And outright damage (chips, etc) will be obvious. I'd say find the best
standard you have for "straight" and try to find any gaps between it and
the face of the stone. I'm not a metrologist, though.

And if it is not worth refurbishing, what have you used an old surface
plate for? I've already got a gravestone. ;)

I watched someone cutting a watermelon on a granite surface plate -
seems they had inherited the QA department, and the employer (large
company whose name sounds an awful lot like "GE") decided that they
didn't need to actually inspect the parts, because (insert mumble here).
So, this surface plate had turned into a breakroom table. Un Farking
Believable.

Thanks for any suggestions, comments or wisecracks.

What, here? But yeah, get a straightedge and a bright light. If
there's any visible gaps, get out the feeler gages and see how bad they
are, and compare that with your personal tolerance.