Topic: Bright Zinc Plated Bolts > Dull Finish

[jwc66k]

There is really no such thing as ?dull zinc? plating. It came out in the 1920s when platers had very crude systems.
It?s just plating without brightener.

Really? Like I said, this dull zinc process is about 10 years old. It's new, not a 1920s version. I've worked with this particular plating shop about 40 years ago when I was the Production Control/Inventory Manager in a high tech company in Silicon Valley. When this process was recommended for use on Mustang hardware, I believed them. What ever your requirement is, I'll go with the experts.
Jim

[Drew Pojedinec]

What I?m saying, unless they invented a process that hasn?t been published, spoken about, etc? it isn?t new.
All zinc plating is dull without brighteners, basically whatever the anode looks like, But the brighteners impact the quality of the plating dramatically.

There are other ways to transfer zinc to steel. Tumbling with zinc, or using zinc shot work well.
With the zinc shot I have, I can make a bolt look at he same color/texture as galvanized pipe for instance.

Ask these experts about the technique used. Curiosity as it is. 

[Bossbill]

I had lots of issues with plating while I was learning the process using Caswell products.
If any part of the multi step process goes wrong you have failure.

I finally got decent plating, but it was dull. The real key to nice, bright plating was using their brightener. Although Caswell infers you don't need to add brightener very often I use it ever 5th or 6th run. You only need 1/2 teaspoon in a 2 1/2 gallon bath.

Be aware that the fumes coming off muriatic acid stripping are nasty.

[Bob Gaines]

I had lots of issues with plating while I was learning the process using Caswell products.
If any part of the multi step process goes wrong you have failure.

I finally got decent plating, but it was dull. The real key to nice, bright plating was using their brightener. Although Caswell infers you don't need to add brightener very often I use it ever 5th or 6th run. You only need 1/2 teaspoon in a 2 1/2 gallon bath.

Be aware that the fumes coming off muriatic acid stripping are nasty.

The fumes let you know immediately that they are nasty .  The clueless should not be working dangerous chemicals to begin with. If you cant smell the harsh acid fumes and are taking masking precautions then you are most likely all right. 

[alanmac]

I found an option to make bright zinc finish look dull. The attached photo shows the before and after change. In person the change to dull is very apparent.   I used Krylon Fusion all-in-one Flat Clear from Lowes for $8.  Its very easy and an inexpensive.     

[jwc66k]

I'll be blunt. I want "chrome" (-S13) to be shiny and I don't want clear zinc (-S8 and others) to be confused with it. I also want to have items cad plated (-S7) but pollution laws make that process difficult and very expensive (it's on track to be banned). Dull zinc is a good substitute for cad. It's your choice.
Jim