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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W1EUJ on June 14, 2005, 08:46:12 AM



Title: Paint Stripping / Copper Plating
Post by: W1EUJ on June 14, 2005, 08:46:12 AM
Hello All,

 I have this very special radio I would like to restore to original condition.
It was painted with a very tenacious paint and primer, over copper plating. It seemed to me that the copper plating acted as a sacraficial coating that took the brunt of corrosion and left the steel underneath unharmed. From those areas paint stripping was easy (methylene chloride - warmed to 30C). From the uncorroded areas, the primer refuses to go without sanding.

First Question: Where do you send items for chemical heavy-duty paint stripping (non-abrasive)?

Second Question: And if it is impossible to remove the paint without abraiding the copper plating, is there a plating shop somebody has used with success? The ones I call want nothing to do with my chassis (may need additional cleaning and copper plating removal)

Dave Goncalves
W1EUJ


Title: metal strip
Post by: Tom W2ILA on June 24, 2005, 07:44:17 AM
Try Contact Metal Strip of Net England 508-754-2047
I used them for automotive work a few years ago but do not know if they are still in business.  You will need to ask how it reacts with the copper.

 If you find the copper needs to be replated check Hemmings Motor News for chrome platers.  They often have the facility do work with copper.  They could also polish it for you if you.

Tom W2ILA


Title: Paint Stripping / Copper Plating
Post by: Todd, KA1KAQ on June 24, 2005, 02:11:33 PM
Quote
If you find the copper needs to be replated check Hemmings Motor News for chrome platers. They often have the facility do work with copper. They could also polish it for you if you.


 IIRC, part of the rechroming process involves plating with copper first. Need to look into this more as dad picked up a nice 1950 baby Lincoln last fall and some of the chrome is crappy. So far I've found out that they have 'street chrome' and 'show chrome', so many the copper plating is only used in show chrome. But it does support Tom's suggestion.

~ KAQ


Title: Chrome
Post by: Tom W2ILA on June 24, 2005, 03:01:52 PM
Hey Todd,
I checked out those Chromer words once.  A shop in Fall River had samples and basically the street chrome just goes through less buffing, leveling and meticulous work.   It is probably what most cars came from the factory with.  The show chrome is like looking into a mirror.  They buff and polish and level the copper to perfection .  Everything has been surfaced and its gorgeous.  Most people wouldn't notice the difference though.
Have fun.

Tom


Title: Paint Stripping / Copper Plating
Post by: WBear2GCR on June 27, 2005, 05:54:11 PM
There are numerous first class plating shops (non-automotive) that cater to industrial accounts in Mass & Ct. Too many to list for sure.

(and in most other areas of the country - and you can always ship the chassis)


They will take ur chassis and drop it into an acid bath that will remove all the "paint" on the surface. Standard operation prior to plating.

Depending on what sort of "paint" this was you might try testing with a few selected solvents yourself, in WELL VENTILATED AREAS (outside, eh?). Lacquer Thinner, Acetone, MEK, etc...

Oven cleaner (Lye) tends to soften some paints too.

I understand that the usual operation for pitted automotive parts is buffing, plating thick with copper, buffing smooth, replating a copper flash coat, checking for flatness (repeat if needed) then nickel, then chrome. There is soft chrome (used for domestic stuff) and hard chrome (used for industrial stuff - automotive etc). The soft chrome looks shinier, but doesn't stand up to the wear as well. I am told...

Anyhow any good or better quality industrial house can handle your problem without any difficulty.  The bigger houses can be identified by the scope of their available processes - hard anodize, hard anodize with teflon, anodize, plating of assorted metals... go with a big house if you want to be sure of the level of expertise - but be prepared to pay a full tank charge unless the guy you talk to happens to like you or hobbyists in general!  :D

     _-_-bear
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