Technical Prepping parts for chrome

Recently, I posted about dimpling some valve covers and it got me to thinking. If a guy was going to get the end product he desires, what can he do to help the process? I know that sometimes you end up getting charged more for customer prepped parts.

With that said, the level of craftsmanship on the hamb far surp***es most message boards.
My dad was a chemist years ago. He specialized in plating.

My question is this, since the plating shops were skipping the copper base these days, has anyone built their own copper plating vat?
Do you sand the copper in between coats? Can copper be stacked ?

 

Why are they skipping copper? I've not heard that. That is what keeps the metal from rusting.

 

Save money. The go straight to nickel, then chrome.

 

I'd go to another shop, copper is important. They also use it as a filler for small imperfections. Plate it and sand or buff until the crevis is filled.

 

Good plating shops don't skip the copper.

 

There is only a few that use it and they let you know how expensive it is.

 

You'd be surprised at how many shops skip it. I ask every one I call.

 

My guy coppers, in fact he does just copper. He is going to do a flip cap for me in copper. Copper is like the body filler under your paint, it fills the imperfections. I suppose you can skip it but I don't think the end product would be very nice unless the piece was perfect going in the tank.

 

Chrome without a copper base is not going to last.
It will not last nearly as long as good triple plate chrome .
Like the man said,,,,that is what keeps the metal from rusting through.
And,,,,the copper is very soft and malleable,,,,,,polish the copper and the top will look like gl***.
Nickel is pretty tough,,,,,but it will rust eventually.

I’m sure you are right,,,,the shops probably have cut out the base plate,,,,,but it’s still poor quality,,,,,it will rust over time .
The best chrome that doesn’t rust has a very heavy copper layer underneath .
It’s probably very expensive too ,,,,lol.

Tommy

 

We would get parts sent back in copper.
Part of my job was filing the copper straight amd double checking fit.
Then sent back to the plater.

 

Also, be sure to use the high quality hexavalent chrome process.
It produces the best chrome finish.

 

True. It's also highly toxic. It's a carcinogen. All the good stuff is. I'm sure that factors into pricing. EPA drives the recapturing process.

 

If they are not using copper they are not a good chrome shop.

 

Agreed.

 

Not trying to beat you up but take a look at factory chrome valve covers, say from a SBC or BBC. They didn't have copper and that's why originals are rusted in the corners.

 

I don't think anyone is disputing the fact that copper is imperative. My question is if you wanted a better finish, what can I do to improve the final product?

 

Smoother is better. Pretty simple sounding, but hard to do. Like on your valve covers, if you cut and weld, then all you those joints will need to be perfected. But if you are able to press in the humps, then there’s no weld to worry about.

When sanding, start with the finest paper needed to remove the bad spot. Don’t go whole hog everywhere with 80 grit if most of the piece is already 200 grit quality.

When sanding, get all the scratches out before going to the next finer grit. If the scratch won’t come out with 200, it surely won’t come out with 400.

And, as everyone has said, find a chromer who uses copper.

 

I just don't wanna do all the work if they will just strip it and start over....
But, if it helps and will end up with a superior finish, then I am all in.

 

I think they actually use two types of copper in real decorative Chrome plating. The first is Cyanide based and for obvious reasons needs to be handled properly and is expensive. Cost and environmental reasons may be why some are skipping it. The acid copper I believe is the body filler step. I actually worked in a plating shop Anodizing aluminum parts when I was 17 yrs old and it was crazy in there, I could tell a few stories about things that happened there.

Probably better to let them do the prep work.

 

I would think asking here if you can do your own copper plating is kind of pointless. Only the plater you end up using can tell you that. I would imagine any plater worth his salt would refuse to plate anything that came in with home brewed copper on it. They have no idea what has been done and if it has been done properly and they are putting their reputation on the line.

 

STRIP WHAT? Are you working with a old chrome part? Strip it to BARE METAL before you do any work on the piece.

 

Chris, before taking my axle to the plater, I filled in gouges with a MIG, then ground and sanded everything smooth, down to #400 grit.

When I dropped it off, the plating guy was impressed, but cautioned that his guys would still need to do more prep before dipping it in the copper tank.

My prep saved me a lot of labor $$, but I couldn't say how much.

The axle should be ready for pickup next week.

 

here's a terrific thread about chrome prep with insight from @Moriarity , @langy and @Squablow .

https://www.jalopyjournal.com/forum/threads/chrome-pricing.970164/

 

I was told that if you buy chrome steel wheels, no copper is used. The reason given is when welding the two plated parts together, the copper will contaminate the welds.

 

That’s why chrome steel wheels rust so quickly.

 

I just happened to bump into a fella that worked at the shop that did all the chrome on my coupe back in the 80s. He said my dad would practically polish his parts before taking them to the plater, and that they all liked it because they were ready to dip on arrival.

I guess he trusted his own prep work more than theirs.

 

Any lump or divit will be magnified when they plate it. Polish to perfection and they will have less time involved.

 

We had some shafts at work that were used on a bomb rack that we built many thousands of, they were sold all over the world to friendly air forces. Simple shafts, no holes anywhere but tight tolerances all over. The drawing was very specific on how much nickel and chrome, no mention of a copper strike.

One vendor was in with the parts he was struggling with. He was centerless grinding the outer diameters, stripping the old plating and having then re-plated. I was brought in to see if his parts could be salvaged. I had read the drawing and all the plating specs, I had notes on the pre-plate dimensions on the raw parts, with nickel and finally the chrome. It was permitted to over-chrome and grind it to the final size.

The drawing also specified that center holes were permitted, opening the door for grinding between centers. These parts had no centers. Since it was really impossible to tell what was going on with the parts after a few re-work cycles, my recommendation was to s**** the parts and make them over. Which went over like a fart in church.

But they did it, found another shop who went with centers. I recommended a hard-chrome shop (Erie Chrome) and quickly got him vetted. We got the parts back, they were beauties. I looked closely at the centers and saw evidence of copper... I did not say a word.

 

Man, I searched the other night and didn't see that one. Thanks.