Topic: Zinc Plating -

[jwc66k]

I picked up some parts I had zinc plated a little while ago, and got a relatively new finish (two years for this plate shop) on some items. It's referred to as "dull zinc", as opposed to "clear zinc". A comparison picture of two trunk strikers shows the difference. The dull finish replicates cadmium plating, aka soft silver, Ford finish code -S7. Finish code -S8 does not specify "chromate", see finish code -S9 and others, or dichromate, see -S35 and others. However, a chromate treatment does provide additional corrosion protection and is a good surface preparation for painting. Specifying zinc dichromate may result in a yellowish tint per its industry standards. My plater, Bob (a long time Silicon Valley business owner, over 50 years) recommends to get the correct zinc finish, use the terms "clear", "dull" or "gold". He also does black zinc but says that process is more expensive, higher materials and labor costs.
Jim

[CharlesTurner]

Considering Cadmium plating is probably becoming obsolete, it seems like the only alternative.  Here are some parts that I had Cad plated about 10 years back... more silvery looking.  Unlike zinc plating, I had found Cad to be relatively consistent in the final finish.  Zinc could vary with either shiny silver or silver with bluish hues.

[Bob Gaines]

With my home plating set up it is easy to get the dull zinc. Sometimes too easy as in when you want it shiny it comes out dull. You have to have the correct brightener agent added to the plating brew for it to come out shiny.

[J_Speegle]

.................. My plater, Bob (a long time Silicon Valley business owner, over 50 years) recommends to get the correct zinc finish, use the terms "clear", "dull" or "gold". He also does black zinc but says that process is more expensive, higher materials and labor costs.
Jim

Yes the terms seem to be the challenge at times depending on where you are located. Suggest that anyone having someone do this for them to ask to see samples first and then confirm what the platters terms are for each so that you get what you expected to get. Also on more recent batches have found that allot fo local platers are now doing parts in baskets  rather than manually tying each part along a strand of bailing wire as was typical years ago. Often could save a few bucks if you just told the platter to leave them on the string and you would remove them. Also found some batches benefited by coating them in some oil to deduct the chance of oxidation over time 

Just what has worked for me

[jwc66k]

Also on more recent batches have found that allot fo local platers are now doing parts in baskets  rather than manually tying each part along a strand of bailing wire as was typical years ago.

The "basket" process does not always give good results as it is "static", not moving. Electrical continuity is required to get an even look, and even more important, a consistent thickness (it's not much, 0.00015 to 0.0002). A more common process is "tumble plating". It has its drawbacks as scratches may develop and parts sometimes get lost in the tumbler. My plater currently wires most everything, but that process occasionally leaves a "bald spot" where the wire was attached. Almost all thicknesses are measured by elapsed time by a lot of platers along with voltages, temperature and acidity of the bath.
Back when I worked for a living, I preferred to have the tumble process used and specified as such. That was for very large quantities of the same small part. Times have changed.

Also foudn some batches benefited by coating them in some oil to deduct the chance of oxidation over time 

Before or after plating? I send all my parts bead blasted and dry (the current humidity is 33 percent).
Jim

[J_Speegle]

.............. Before or after plating? I send all my parts bead blasted and dry (the current humidity is 33 percent).

After of course  

As for prep depends on the part and its condition. Nuts and bolt sort of things are stripped then wire brushed do to not leave a texture. Just a choice

[CharlesTurner]

The local plater here referred to wiring parts as 'rack plating' and small parts/fasteners as 'barrel plating'.  Barrel plating a large batch of nuts/bolts has usually worked out well for me.  Sometimes there might be a couple pieces that didn't get rinsed/neutralized properly and develop some surface rust.  The rack-plated stuff has been hit and miss.  It was because I sent a few parts back for re-do that the big local plater decided they didn't want to do anymore 'hobby' plating for me.  Found another place, which has since gone out of business, that would do only rack plating.  They were cheap and quick, but the zinc they did was the trivalent plating where everything came out with a lot of bluish hues.  I found I could cut that down with steel wool and chrome polish, but was a bit annoying.

[Bossbill]

I have my plating station set up -- just need chemicals.
I bought the Caswell NSP-2050 on closeout, the buckets at the Depot, the metal rack I stole from the wife's plant nursery and I secured a manual. I have an enclosed fish tank heater, bubble-rator, clips, wire plus a copper attachment bar too. The rack is the return path.

I'm ready to buy the Caswell products.
I'll need zinc plate, the Copy Cad, brightener and zinc dichromate. And gallons of distilled water. Some have suggested a 2.5-5% muratic acid bath prior to dichromate. Anything other products? I can't think of anything ...

Since I have everything except chemical and the plate I have no use for a "kit".

But I do wonder if their "Zinc and CopyCad anode" is anything special? They want $25 for a 4x8 piece of what I believe is just 99.5 pure zinc. I can get two or three plates for $25 elsewhere.

Any help here? Is it just pure zinc (or close)? How thick is your Caswell plate?

[preaction]

I believe Jim Cowles advertises a Cadmium service.

[Bossbill]

There's a lot of places I can send stuff to be plated -- by someone else.
I'm not interested in that.

All of the equipment above is for DIY in my shop.

[preaction]

Bill, you have an impressive set up from what my experiences have shown me is that cleanliness is most important I mentioned Jim because of the scarcity of Cadmium plating and its most likely not able to be done in a home operation.

[Bossbill]

For those of you who have not visited the Caswell Plating site, this is not the cadmium plating that the plating shops use. Caswell calls it CopyCad in that it very closely approximates the look and the protection of true Cadmium plating.
If done properly you can't tell the difference and it's also quite durable.

For extra credit the gold dichromate is done right on top of the CopyCad and looks like originally done gold dichromate.

And, it does not use the extremely nasty chemicals associated with traditional Cad and dichromate plating.

Back to the original query -- anyone using this system with other than Caswell zinc?

[Bob Gaines]

For those of you who have not visited the Caswell Plating site, this is not the cadmium plating that the plating shops use. Caswell calls it CopyCad in that it very closely approximates the look and the protection of true Cadmium plating.
If done properly you can't tell the difference and it's also quite durable.

For extra credit the gold dichromate is done right on top of the CopyCad and looks like originally done gold dichromate.

And, it does not use the extremely nasty chemicals associated with traditional Cad and dichromate plating.

Back to the original query -- anyone using this system with other than Caswell zinc?

99.5 pure zinc is going to give similar results regardless of who you buy it from . It is what it is. Just my experience. FYI have a fan for ventilation and also where a mask and gloves.It is better to be safe then sorry IMO.

[67350#1242]

Another more economical option is Moss Control Strip:

https://www.acehardware.com/departments/lawn-and-garden/gardening/seeds-and-bulbs/7311442?x429=true&utm_source=google&utm_medium=cpc&gclid=EAIaIQobChMI0t_E-8fi4gIV2rfACh3FRwG7EAQYASABEgKKdfD_BwE

99% pure Zinc in a 50ft roll for less than $30.

[Bob Gaines]

Another more economical option is Moss Control Strip:

https://www.acehardware.com/departments/lawn-and-garden/gardening/seeds-and-bulbs/7311442?x429=true&utm_source=google&utm_medium=cpc&gclid=EAIaIQobChMI0t_E-8fi4gIV2rfACh3FRwG7EAQYASABEgKKdfD_BwE

99% pure Zinc in a 50ft roll for less than $30.

Yep .I got some from another MFG and have used it successfully.