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**johnshenry** · 05-28-2002, 01:39 PM

Re: Plating pot metal w/copy chrome

Ok, a little more reading on the site/forum, and I think I may have answered my own question (but still have a few more).

It looks like I have a pot metal part and I need the Pot Metal Primer kit.

1. Is the POt metal primer kit the same thing as the "POT METAL Electroless Nickel Plating Kit"? (ALZ59)

2. Did I truly contaminate my 1 gallon of copy chrome solution by hanging a pot metal handle in there for 20 minutes? (It was new before that). I hope not.

3. If the answer to #2 is "yes", can I buy one gallons worth of copy chrome crystals? Site only lists 2 gallons worth for $125! Expensive mistake!!

4. How can I strip that handle (see pic links above). Would like to try to plate it again. Can I use sulfuric acid solution and reverse polarity de-plate it? If so, what kind of anode to use? (or is it a cathode in that case?) Will plain mild steel work??

Thanks,

John Henry
Marlboro, MA

**mcaswell** · 05-28-2002, 04:12 PM

Re: Plating pot metal w/copy chrome

4. Stay away from the acid strippers when using pot metal (or be extrememly careful) Acid + Pot Metal Part = Dissolved Pot Metal Part. For safety I would use a mechanical stripping method, like sand-blasting, abrasive wheels, buffing etc.

**johnshenry** · 05-29-2002, 09:16 AM

Re: Plating pot metal w/copy chrome

Thanks for the answers. So my idea to de-plate the pot metal handles using a #3 pickle (sulfuric) and reverse polarity is a bad one? I was al ready to go out and buy some acid, but it now just clicked that acid+pot metal=problems.

Can you tell me the best way to filter my Copy Chrome solution? Something in the manual about charcol filter? Where to get this kind of charcol? Is it the kind found in aquarium supply stores?

I did try the copy chrome system with s few pieces of copper pipe first, and had execellent results.

I ordered the pot metal primer and some brightener. What kind of blasting abrasive do you recommend for pot metal? Would aluminum oxide be too aggressive??

Thanks...

**48Buick** · 05-29-2002, 06:20 PM

Re: Plating pot metal w/copy chrome

John:
First a suggestion.
Dont use your good parts to learn on. There is a learing curve with plating, especially potmetal. Get some copper tubing,buff it and plate that to start.
Then when you feel comfortable, do your parts.
As for potmetal, it is very, very finiky!
I sandblast my potmetal until all the chrome is off,(this also gives the next plate a nice fresh coat of nickel to adhear to.
After that I soak it in a mix of 75% water and 25% phosphoric acid. Clean it off with a small steel toothbrush and water until the areas that were dark are nice and shiny. Then boil it in distilled water for at least 2 hours. This will clean out any last acid down in the metal. Otherwise you will get blisters about a week down the road.
I dont know if the Caswell primer eliminates this step or not. Im working mostly with very pitted/deteriorated potmetal. Your handles look pretty good to start with.
After The part is clean I put a strike plate on it and then into the acid copper for about an hour.
Then you work it up from there.
Good luck and practice, practice, practice!!
48Buick

Then you can plate

**johnshenry** · 05-30-2002, 09:24 AM

Re: Plating pot metal w/copy chrome

Thanks for the tips 48Buick....

I did try a few pieces of copper pipe, buffing pre and post plating, and it came out real nice. The handle I tried was my worst one, I was willing to give it a try. I can scrounge up a lot of later model handles, even cut them apart, for "test pieces" before I dunk one of my good handles.

Where can I buy phosphoric acid?

What do you sandblast with? I have a small bin setup and use silicon carbide (Black Beauty, very fine grit), but I have a hard time beleiving that it would strip chome. I did most of my handles with ScotchBrite roloc discs, but it was too hard to get the crevices.

One of my friends HAS sucessfully acid de-plated a pot metal handle, and then nickle plated it. Send me a pic, looks nice. Fluke?

Most of the handles are pretty dood to start with, but some have pits down in that crevice "rib" area. How best to address these? Dental drill pits with a Dremel? How to fill? I bought some of Caswells Solder-it, will that work?

Thanks for any other tips. I am sold on the Copy Chrome if I can get it to work well. I am a partner in a small resto/parts biz (www.zarwerks.com) and expect to do a dozen or so of these handles a year.

John H.

**48Buick** · 05-30-2002, 11:20 PM

Re: Re: Plating pot metal w/copy chrome

John:
Good, get some scrap handles and play with them.
I get my phosphoric acid from a pool supply dealer/chemical supplyer down the street from me. You can also try hobby chemical suppliers on the internet.
You can also use NAVEL Jelly to do it. It is mostly phosphoric anyway. Just a little more dilute.
I sandblast with regular old fine white sand that I get at HOME DEPOT.
It sparks when it is taking the chrome off. Once you see the sparking stop...the chrome is gone.
I tried glass beads and they just dont cut like plain old sand.
All I use is a small bin set up also.
You can acid strip the chrome if you heat the hydrocloric up and put the handle in it. It will all of a sudden bubble like you put it in soda and all the chrome will dissapear.
Problem with this is that if you have any pits in the potmetal then it will really attack those areas vigorusly.
The hydrocloric will get down into the metal and give you problems in the form of blisters down the road. I dont know why the phosphoric works but...it does.
As for the pits, After you clean with either the phosphoric or hydrocloric/muratic acid. Scrub the living tar out of the part with a steel toothbrush until you see shiny metal where the zinc metal has been turned dark. After scrubbing if you still see some dark areas in the pits, then drill them out with a dremal.
From there I put a stike plate on the part, and then into the acid copper for at least a hour. Then I solder up the pits, sand them down along with sanding the surface of the part. After that its back into the acid copper to cover the solder and build up the surface some more.
Then you can buff, plate with nickel, and chrome.
I left out the cleaning and buffing parts inbetween the copper/nickel/chrome.
Its a long process and takes patience.
Keep at it!
48 Buick

Thanks for the tips 48Buick....

I did try a few pieces of copper pipe, buffing pre and post plating, and it came out real nice. The handle I tried was my worst one, I was willing to give it a try. I can scrounge up a lot of later model handles, even cut them apart, for "test pieces" before I dunk one of my good handles.

Where can I buy phosphoric acid?

What do you sandblast with? I have a small bin setup and use silicon carbide (Black Beauty, very fine grit), but I have a hard time beleiving that it would strip chome. I did most of my handles with ScotchBrite roloc discs, but it was too hard to get the crevices.

One of my friends HAS sucessfully acid de-plated a pot metal handle, and then nickle plated it. Send me a pic, looks nice. Fluke?

Most of the handles are pretty dood to start with, but some have pits down in that crevice "rib" area. How best to address these? Dental drill pits with a Dremel? How to fill? I bought some of Caswells Solder-it, will that work?

Thanks for any other tips. I am sold on the Copy Chrome if I can get it to work well. I am a partner in a small resto/parts biz (www.zarwerks.com) and expect to do a dozen or so of these handles a year.

John H.[/quote]

**mcaswell** · 05-31-2002, 12:04 AM

Re: Re: Plating pot metal w/copy chrome

48buick wrote:
I dont know if the Caswell primer eliminates this step or not.

Yes it does, although your steps certainly wouldn't hurt. The cleaner your pot metal, the better.

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Plating pot metal w/copy chrome

Plating pot metal w/copy chrome

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