ConcoursMustang Forums

Restoring - General discussions that span across many different groups of years and models => Processes, Products & Techniques => Topic started by: alanmac on July 31, 2023, 02:31:32 PM

Title: Bright Zinc Plated Bolts > Dull Finish
Post by: alanmac on July 31, 2023, 02:31:32 PM
I had some of my original bolts and hardware plated at a local shop.  It was pretty much a disaster, that I wont go into.  Is there a way to change the shiny bright appearance to a dull finish?  Alan   
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: Bob Gaines on July 31, 2023, 03:33:02 PM
You might try a bath in vinegar or stronger acid. It may dull the finish on its way to eating off the finish. You will have to play with time in bath . It will also depend on strength of acid used.Obviously you need to try a sample first to see how that approach works. I use muriatic acid to strip zinc off of nuts and bolts for example
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: J_Speegle on July 31, 2023, 10:55:57 PM
Vinegar will strip off the zinc completely so either water it down for the bath or use very very short intervals in the bath. Another option would be a light acid wheel cleaner - the stuff made for non- clear coated rims. Spray it on and keep it moving - hands covered with rubber gloves will protect your hands. Don't let it dry on the surface
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: alanmac on August 01, 2023, 11:47:26 AM
Thanks for the input.  I tried vinegar before and it turned black, but watering it down and keeping an eye on the time might work.  I was wondering if a tumbler with some sort of abrasive in it could work? 
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: jwc66k on August 01, 2023, 02:02:14 PM
I was wondering if a tumbler with some sort of abrasive in it could work?
Look up "Phosphating 101" in "Processes, Products & Technique".
Jim
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: alanmac on August 01, 2023, 02:51:14 PM
Jim, I am not sure what you are suggesting. 
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: jwc66k on August 01, 2023, 02:54:46 PM
I am not sure what you are suggesting. 
a tumbler with some sort of abrasive in it could work?
Look up "Phosphating 101" in "Processes, Products & Technique".
Did you look?
Jim
Let me help - https://www.concoursmustang.com/forum/index.php?topic=4624.msg25789#msg25789
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: alanmac on August 01, 2023, 03:57:52 PM
Is this the key?  tumble in metal filings for a week; dip in kerosene; air dry for at least two weeks; Beer drinking is encouraged.
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: jwc66k on August 01, 2023, 04:15:45 PM
Beer drinking is encouraged.
Yes. While processing. I recommend a Brandy Manhattan (an off-road enthusiasts' preference), on the rocks, no bitters, no cherry, to be made and consummed at the end of a motor vehicle restoration daily cycle.
Jim
Picture attached of my tumbler stuff. It is slow, meticulous and effective. This one is from https://rocktumbler.com/thumlers/ Don't forget to "rinse" the metal filings off in kerosene. Don't use water. It causes rust.
The second picture is my vibrator (Eastwood, I think) but it is noisy and does not clean threads well. Plus the glass pyramids get stuck in the threads of nuts and between the head and washer of that type of screw.
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: Bob Gaines on August 01, 2023, 04:30:49 PM
I had some of my original bolts and hardware plated at a local shop.  It was pretty much a disaster, that I wont go into.  Is there a way to change the shiny bright appearance to a dull finish?  Alan   
Your vinegar is probably too weak of acid.  3-5 percent is typical household strength.  When I use muriatic acid it will not turn black .It bubbles quickly as it dissolves the finish . A finish on a bolt will typically completely dissolve  in 4-5 minutes (when it stops bubbling) .   If you use that I would suggest you will test starting with 5 seconds and moving up in 5 second increments checking for results. Of course use gloves and safety glasses.
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: jwc66k on August 01, 2023, 04:55:49 PM
I had some of my original bolts and hardware plated at a local shop.  It was pretty much a disaster, that I wont go into.  Is there a way to change the shiny bright appearance to a dull finish?  Alan   
Yes. There is a recent plating process called "dull zinc". It came about about 7 or 8 years ago. It is my understanding that some shops can't/don't do it. The results are "close" to cad plating.
Jim
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: alanmac on August 01, 2023, 05:02:40 PM
Does your plater have the dull finish process?  I only have 16 bolts.
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: alanmac on August 01, 2023, 06:58:04 PM
Thanks for the options.  I'll do some testing...
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: rockhouse66 on August 01, 2023, 07:26:10 PM
My plater told me if I want dull zinc to find someone who does cad plating  ::)
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: Drew Pojedinec on August 02, 2023, 05:22:59 PM
Not that I know anything about plating?.

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.

Plating without maintenance brightener is a pain in the butt.
I can understand why a professional wouldn?t want to do it for a few reasons.
One is that to do it for a few bolts wouldn?t make sense at all.
Plus the actual plating process is crappier.

If you want it to look dull dip it in a sealant. Generally speaking a sealant like I use and hot air drying makes the part come out dull and lifeless.
If that is too troublesome, just spray the chromated bolts with wd40 and hit them with some steel wool.
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: jwc66k on August 02, 2023, 06:42:48 PM
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
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: Drew Pojedinec on August 03, 2023, 11:01:32 AM
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. 

Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: Bossbill on August 03, 2023, 12:12:28 PM
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.
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: Bob Gaines on August 03, 2023, 02:55:06 PM
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. 
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: alanmac on August 03, 2023, 06:01:17 PM
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.  :)   
Title: Re: Bright Zinc Plated Bolts > Dull Finish
Post by: jwc66k on August 03, 2023, 07:56:25 PM
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