Randall:
Not to be difficult, but I was always under the impression that after having
stripped the part the chrome shop was supposed to fill in imperfections
using a metal "paste" that could then be buffed to the same level as the
original unpitted surface. That way you get a smooth base for a nice shiny
chrome surface on a part that has the original relief. Of course with heavy
steel parts they are supposed to weld in new metal, filling is just for
decorative parts. This is why they charge so much, the work is done exactly
as a normal car body job, with recreation of the original look by a filling
and sculpting approach, not by just grinding the part down to a uniform
surface. Frankly if I gave somebody an rare part for chroming and they
ground off all the details, I would bounce it off their thick heads rather
than pay for it and then demand that the part be done properly.
Mark Hooper
-----Original Message-----
From: Randall Young [mailto:ryoung@navcomtech.com]
Sent: Monday, September 23, 2002 2:09 AM
To: triumphs@autox.team.net
Subject: RE: chrome
> Moral of the story - ask lots of questions of your chrome plater to ensure
> they do it right or don't use them.
Actually, removing all surface imperfections _is_ the "right way", a rough
surface will not shine no matter how much chrome you lay on it. And the
labor to do this is part of the reason chroming is so expensive. If you
want a part chromed without having the imperfections removed, you have to
explain this in detail (and preferably in writing) to the shop doing the
chrome. Having them sign a copy of the instructions for you to keep is
probably a good idea too, gives you some basis for a lawsuit if necessary.
There are several different plating chemistries around, the old cyanide
baths are considered very "environmentally unfriendly" so other formulas had
to be developed. 'Hard' and 'bright' are merely two areas on a rather large
plot of temperature, time and current density, at least for the old cyanide
based method. Might be different for the newer methods, I suppose. Don't
know what Caswell sells, but I'll bet it isn't cyanide. Chrome can even be
ion-sputtered, although I don't know of anyone that does this on a
commercial basis. (Hmmm, never did look into how they chrome plastic ...)
Randall
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