Just for the record here the shop forman of the plating shop I took my
parts into had done a presentation at our car club he had explained
their process of dealing with pitted pot metal parts. He said they strip
the old chrome first, then glass bead the part, and if required they use
a small burr and a die grinder to finish cleaning any of the pits. After
this the part goes in a special pre plate solution for pot metal, then
the nickel plate, and then a very heavy copper plate which gets
sanded/buffed down and repeated until all the pits are smoothed out,( he
said some shops will silver solder the pits after the first copper plate
but that their shop doesn't like the results they get from that method),
after the copper is all smooth and shiny the part gets a final nickel
plate, buffed, and the chrome plate.
Now if the shop had done what they said they could do I would be a happy
customer but instead with my Fiat hood scoop they ground entire part
down until all the pitting was gone this made the whole part about a
1/32-1/16" smaller than original and in the process they made the
corners of the scoop a 1/8" radius round over instead of the original
sharp pointed corners. The door handles I can't understand how they
messed them up as the chrome was in fairly good shape to start with but
now there is a detail line that had run the length of the handle that is
gone and the push buttons now have enough flats on them that you could
turn the with a socket. When I complained about the work they did they
felt they had done good work on the door handles claiming that was all
they could do with the pitted parts but the before digital picture show
no pitting, the hood scoop they offered to put a heavier layer o copper
on to get it close to it original size but that won't fix the corners
they rounded over so I'm looking for another 1963 Fiat Cabriolet hood scoop.
I don't know for certain what the temperatures where in all the tanks
but I thought 150 F was what I saw on the chrome tank but they weren't
plating anything when they gave use a tour of the shop so it might be as
high as 450 F.
Doug Hamilton
1960 Triumph TR3A
1963 Fiat Cabriolet
>Date: Mon, 23 Sep 2002 13:07:22 -0700
>From: Randall Young <ryoung@NAVCOMTECH.COM>
>Subject: RE: chrome
>
>>> 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.
>>
>
>Mark, I will freely admit that my knowledge of chrome plating may be
>somewhat dated. But if anyone has developed a paste that will conduct the
>same as metal (remember this is electro-plating, current = metal), be as
>strong as metal, bond the same as metal, and survive several hours in the
>various hot chemical baths required (eg chromic acid, 450F, 2 hours), I've
>not heard of it. Steel and aluminum can, of course, be filled by welding
>and ground back to the original profile, but even chroming over welds can be
>problematic as the weld metal frequently doesn't plate the same. In theory,
>'pot metal' could also be welded, but in practice it's almost impossible to
>successfully do. In either case, chrome shops (at least the ones I've
>visited) don't normally do such things.
>
>So, I stand by my statement. If you take a pitted piece in to be rechromed,
>and you don't want the pits ground out, best to say so in writing. Contrary
>to what some may think, chrome shops do not like having unhappy customers,
>they will do anything within reason to make you happy. You just need to be
>sure they understand what that is.
>
>BTW, here's a listing of chrome shops I found while surfing just now. Might
>be useful to someone.
>http://www.bikerlink.com/Chrome/Chrome_&_Plating_Index.html
>
>Randall
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