Zinc Electro-plating (1 Viewer)

[avicenna110]

Beautiful job! The yellow chromate looks great and is correct for many parts, if that is your thing. I'm sure if it is a Concourse restoration that won't be subjected to weather like a daily driver, it will be just fine. I am looking for a little more protection, however, and leaning toward nickel plating.

thanks! Interesting you mention this because I got into this so I could do Nickel plating and that’s the first thing I tried. It seemed easier on paper and didn’t have the extra step of yellow chromate. Nickel is a harder metal and looks shinier too (and prettier in my opinion). But what convinced me to do Zinc instead was the fact that Zinc provides a sacrificial layer that corrodes first before steel, and Nickel does not ( does the opposite in fact as steel is more active than Nickel but less active than Zinc). So if Nickel plate is not perfect and has holes, the surface underneath will corrode first, whereas with Zinc plating even imperfect plating provides protection. Please correct me if my understanding is not right.

There is also Nickel/Zinc plating where one of the electrodes is Nickel and the other is Zinc and from my understanding the setup is similar otherwise. I haven’t tried this yet.

So far I’ve also applied a layer of quality clear coat on the parts, to make them shinier and provide somewhat of an additional layer of protection.

 

[Engineer8000]

Correct Zinc is above Iron and Iron above Nickel in the reactivity series. Nickel makes a nice finish though. I did these end caps for the proportioning/combo valve, Nickel first then Copper.

 

[Honger]

Correct Zinc is above Iron and Iron above Nickel in the reactivity series. Nickel makes a nice finish though. I did these end caps for the proportioning/combo valve, Nickel first then Copper.

View attachment 2864219View attachment 2864220

Have always wanted to open one of those proportioning valves… great pics. Did you find replacement internals?

 

[h82crash]

thanks! Interesting you mention this because I got into this so I could do Nickel plating and that’s the first thing I tried. It seemed easier on paper and didn’t have the extra step of yellow chromate. Nickel is a harder metal and looks shinier too (and prettier in my opinion). But what convinced me to do Zinc instead was the fact that Zinc provides a sacrificial layer that corrodes first before steel, and Nickel does not ( does the opposite in fact as steel is more active than Nickel but less active than Zinc). So if Nickel plate is not perfect and has holes, the surface underneath will corrode first, whereas with Zinc plating even imperfect plating provides protection. Please correct me if my understanding is not right.

There is also Nickel/Zinc plating where one of the electrodes is Nickel and the other is Zinc and from my understanding the setup is similar otherwise. I haven’t tried this yet.

So far I’ve also applied a layer of quality clear coat on the parts, to make them shinier and provide somewhat of an additional layer of protection.

I've read that and that's one type of advantage of zinc. It just seems the zinc plated fasteners you get at the box store start showing rust pretty quickly, so the zinc must be really thin and sacrifices in about 12 months. And, while I'm not a chemist (my friend is), doesn't the oxidizing agent need to reach the substrate for it to rust first? I know you mentioned holes, so rust may start at the holes, but will it creep under the nickel plating and spread? Either way, for me, it fasteners and small parts and I'll try to get a substantial film of plating on.

 

[avicenna110]

I've read that and that's one type of advantage of zinc. It just seems the zinc plated fasteners you get at the box store start showing rust pretty quickly, so the zinc must be really thin and sacrifices in about 12 months. And, while I'm not a chemist (my friend is), doesn't the oxidizing agent need to reach the substrate for it to rust first? I know you mentioned holes, so rust may start at the holes, but will it creep under the nickel plating and spread? Either way, for me, it fasteners and small parts and I'll try to get a substantial film of plating on.

By holes I mean the plating could be porous due to poor plating. It could very easily happen if cleaning the part before plating doesn’t remove all the tiny rust or grease. From this answer on the following forum it seems that exposure on the surface of Nickel is enough to lead to rust but I’m not sure. I would be very interested in knowing the opinion of a chemist or someone who knows the topic.

This is part of an answer here:

Metal Parts that are Nickel Plated but are still RUSTING: FAQs + Q&A Forum

Metal Parts that are Nickel Plated but are still RUSTING. Nickel Plating rapier hilt to Prevent Rust. Why would 1018 steel rust and pit after being nickel plated?

www.finishing.com

“Now picture your steel parts with a thin and porous or pinholed nickel plating on them. Steel is more active than the nickel, so when corrosive forces threaten to attack the nickel, electrons flow from the steel to the nickel; thus the nickel is preserved while the areas of steel exposed through the pinholes lose electrons and corrode away into pitted rust. Poor nickel plating is far worse than no plating at all as it greatly accelerates rusting.”

My objective (I think yours as well) is rust prevention first, and second how the part would look long term. So I rather have the parts not rust underneath (like rust under chrome parts), but I also don’t like the look of faded Zinc-plated parts. It seems that Zinc+Nickel plating would be the best of both but again I’m a rookie at this.

 

[Engineer8000]

Have always wanted to open one of those proportioning valves… great pics. Did you find replacement internals?

Seals are available at mustlecarresearch.com

 

[Engineer8000]

By holes I mean the plating could be porous due to poor plating. It could very easily happen if cleaning the part before plating doesn’t remove all the tiny rust or grease. From this answer on the following forum it seems that exposure on the surface of Nickel is enough to lead to rust but I’m not sure. I would be very interested in knowing the opinion of a chemist or someone who knows the topic.

This is part of an answer here:

Metal Parts that are Nickel Plated but are still RUSTING: FAQs + Q&A Forum

Metal Parts that are Nickel Plated but are still RUSTING. Nickel Plating rapier hilt to Prevent Rust. Why would 1018 steel rust and pit after being nickel plated?

www.finishing.com

“Now picture your steel parts with a thin and porous or pinholed nickel plating on them. Steel is more active than the nickel, so when corrosive forces threaten to attack the nickel, electrons flow from the steel to the nickel; thus the nickel is preserved while the areas of steel exposed through the pinholes lose electrons and corrode away into pitted rust. Poor nickel plating is far worse than no plating at all as it greatly accelerates rusting.”

My objective (I think yours as well) is rust prevention first, and second how the part would look long term. So I rather have the parts not rust underneath (like rust under chrome parts), but I also don’t like the look of faded Zinc-plated parts. It seems that Zinc+Nickel plating would be the best of both but again I’m a rookie at this.

A similar concept would be a buried steel pipe or tank. The pipe or tank is coated with tar and Kraft paper. If there is a flaw in the coating, every bit of electrical potential is concentrated on that one spot and you get pitting corrosion and a hole in your pipe/tank. An impressed current cathodic protection system reverses the current flow and prevents the corrosion.

 

[coinoperated40]

Trying to get the plating in groves or tight areas are robbed by the area around it. You may be able to tape or paint off the area around the grove or gap first, then replate or back in the day of plating, we would make a close electrode to sit inside the hard to reach area. Leave it on for a short period of time then I unclip and let the main plating continue.
Maybe hard to explain or understand. It was a huge learning curve in the plating business. Back in the day.

 

[smokeater]

This a an awesome write-up @avicenna110! I had actually had the 3 gal. CopyCad zinc kit in my wishlist on the Caswell site…seeing how your system produces great results I decided to forego the kit and use vinegar/salt solution instead. I did purchase the chromate, power supply, and leads from them but everything else I’ll source from the home store.

What is the vinegar:salt concentration?

What salt do you use? Water softener salt, kosher salt, sea salt, table salt?

Making a shopping list today!

 

[avicenna110]

Trying to get the plating in groves or tight areas are robbed by the area around it. You may be able to tape or paint off the area around the grove or gap first, then replate or back in the day of plating, we would make a close electrode to sit inside the hard to reach area. Leave it on for a short period of time then I unclip and let the main plating continue.
Maybe hard to explain or understand. It was a huge learning curve in the plating business. Back in the day.

Nice, yes it makes perfect sense. I like the taping idea as it’s the easiest one to try first. Thank you for the tip!

 

[avicenna110]

This a an awesome write-up @avicenna110! I had actually had the 3 gal. CopyCad zinc kit in my wishlist on the Caswell site…seeing how your system produces great results I decided to forego the kit and use vinegar/salt solution instead. I did purchase the chromate, power supply, and leads from them but everything else I’ll source from the home store.

What is the vinegar:salt concentration?

What salt do you use? Water softener salt, kosher salt, sea salt, table salt?

Making a shopping list today!

I was also about to order that same kit but wanted to try this first before I spend the $300. Initially I thought for that kind of money they would provide the yellow chromate and power supply but as you know they don’t. I think in their kit there is a solution called brightner, and with it you don’t need to use steel wool to polish the part after. If this is true (to be verified) I would consider purchasing that separately from them later, they sell it just by itself. I don’t mind polishing the parts by hand, it’s quite quick. I also got black chromate from them, I tried it a few times with poor results but will give it another go and report back. I got a bit better since I last tried it.

I’m using pure epsom salt from a recommendation of a YouTube video. But I’m not sure the difference between them and if one type is better than other, I would think that if it’s pure salt it should be fine. Also I didn’t really see any recommended amount of salt. For the 5 gallon bucket I put 5 or 6 table spoons of salt. I would guess that at some point the solution will saturate and the extra salt will just sit at the bottom with no harm done. Let me know if you find more info on this.

 

[avicenna110]

A similar concept would be a buried steel pipe or tank. The pipe or tank is coated with tar and Kraft paper. If there is a flaw in the coating, every bit of electrical potential is concentrated on that one spot and you get pitting corrosion and a hole in your pipe/tank. An impressed current cathodic protection system reverses the current flow and prevents the corrosion.

Very interesting. This comment makes sense now:

“Poor nickel plating is far worse than no plating at all as it greatly accelerates rusting.”

Thanks for the explanation.

 

[c2dfj45]

We use the Caswell Copy Cad kit....1.5 gallon setup. I bought it a few months ago and have run thru quite a bit of hardware. I bought the power supply on Amazon as well as a agitation pump and aquarium heater. It's easy and actually pretty enjoyable process to do but the key is in prep....like with everything else. We clean the parts in our ultrasonic cleaner. Then they go into the bead blast cabinet(120 grit aluminum oxide). The key step if you want shiny parts is they need to be polished with a wire wheel on a bench grinder. One final clean in an acetone bath then they get wired up and dipped. There was a slight learning curve for a few things like the polishing with the wire wheel(we were just vapor honing after bead blasting). That was about it. Chemicals all remain stable when stored it seems. Easy to setup when we need it. Lots of good videos to learn from....I kind of took a little from each one and applied it to our process.

I mainly bought this so we could do small batches....we have a plater that will do all the hardware at once but sorting them all out and organizing didn't appeal to me plus things can get lost. Way better to do small batches for us since we usually tackle a certain stage of a build at one time(engine, chassis, interior). This is great for that.

Maybe one of the most satisfying jobs around the shop. Take a dirty old pile of metal and make it new.

We use the Caswell blue chromate for the silver parts....gives them a really cool look. Our next batch will be some of the black chromate I think.

 

[avicenna110]

We use the Caswell Copy Cad kit....1.5 gallon setup. I bought it a few months ago and have run thru quite a bit of hardware. I bought the power supply on Amazon as well as a agitation pump and aquarium heater. It's easy and actually pretty enjoyable process to do but the key is in prep....like with everything else. We clean the parts in our ultrasonic cleaner. Then they go into the bead blast cabinet(120 grit aluminum oxide). The key step if you want shiny parts is they need to be polished with a wire wheel on a bench grinder. One final clean in an acetone bath then they get wired up and dipped. There was a slight learning curve for a few things like the polishing with the wire wheel(we were just vapor honing after bead blasting). That was about it. Chemicals all remain stable when stored it seems. Easy to setup when we need it. Lots of good videos to learn from....I kind of took a little from each one and applied it to our process.

I mainly bought this so we could do small batches....we have a plater that will do all the hardware at once but sorting them all out and organizing didn't appeal to me plus things can get lost. Way better to do small batches for us since we usually tackle a certain stage of a build at one time(engine, chassis, interior). This is great for that.

Maybe one of the most satisfying jobs around the shop. Take a dirty old pile of metal and make it new.

View attachment 2865085
View attachment 2865092

We use the Caswell blue chromate for the silver parts....gives them a really cool look. Our next batch will be some of the black chromate I think.

View attachment 2865086
View attachment 2865088
View attachment 2865089

Fantastic results. I also do the polish before plating with a wire wheel and often with dremel+soft abrasive tips. Perhaps you can clarify this for me, how do the parts look after plating and prior to yellow chromate with this kit? Do you need to polish the Zinc prior to yellow chromate as I do?

 

[c2dfj45]

Fantastic results. I also do the polish before plating with a wire wheel and often with dremel+soft abrasive tips. Perhaps you can clarify this for me, how do the parts look after plating and prior to yellow chromate with this kit? Do you need to polish the Zinc prior to yellow chromate as I do?

We do not do any polishing after plating....they simply go from the zinc bath to a fresh water rinse then into chromate.

The key from what I've read and what we do is you have to use zinc brightener....which came with the Caswell kit. I put in 1/2 to 1 teaspoon before we run parts. I have read where people say this is the one product you really go thru. I will look at the parts during the zinc plating and if they look a little grey, I'll add some brightener. If you get it just right, they look gorgeous when they come out....almost like a polished piece. We use the same zinc flashing you are using. 99.9% pure zinc.

Fresh out of the zinc:

Into the yellow chromate

One other important thing I've found is that once we get them out of the chromate(after they have been rinsed), we blow dry them with a heat gun for a little bit. Seems to really pull out the colors and get them to cure a little faster. We do not handle them for about 12-24 hours.

 

[avicenna110]

We do not do any polishing after plating....they simply go from the zinc bath to a fresh water rinse then into chromate.

The key from what I've read and what we do is you have to use zinc brightener....which came with the Caswell kit. I put in 1/2 to 1 teaspoon before we run parts. I have read where people say this is the one product you really go thru. I will look at the parts during the zinc plating and if they look a little grey, I'll add some brightener. If you get it just right, they look gorgeous when they come out....almost like a polished piece. We use the same zinc flashing you are using. 99.9% pure zinc.

Fresh out of the zinc:

View attachment 2865117

Into the yellow chromate

View attachment 2865118


One other important thing I've found is that once we get them out of the chromate(after they have been rinsed), we blow dry them with a heat gun for a little bit. Seems to really pull out the colors and get them to cure a little faster. We do not handle them for about 12-24 hours.

View attachment 2865120View attachment 2865121

Your results look incredible, they put mine to shame I’m also surprised how well the brightner works, better than I thought and shinier than I could ever get them by polishing the pieces. My only question would be if the brightner works with just white vinegar and salt or you need their solution. In the interest of science and sake of this write up I will purchase it and find out I think it was $40 or so (just checked, $17, not bad). And thank you for sharing the other tips and pointers, did I say how good those parts look!!??

 

[JAG666]

View attachment 2862585

the yellow chromate solution I am using is from Caswell for ~$40 and I am happy with it.

If one wants the "yellow" finish, the Caswell product works great.. However, if one
wants a "silver" (true zinc looking) finish, then one will have to locate the "Blue Chromate"..
Last I checked (years ago), Caswell did NOT offer a true "blue" (silver) chromate.. I had to
obtain it from a major plating supplier (sorry, I forget their name, it was that long ago!) I do
recall, it was NOT cheap!!
Charles 1974 FJ40

 

[c2dfj45]

If one wants the "yellow" finish, the Caswell product works great.. However, if one
wants a "silver" (true zinc looking) finish, then one will have to locate the "Blue Chromate"..
Last I checked (years ago), Caswell did NOT offer a true "blue" (silver) chromate.. I had to
obtain it from a major plating supplier (sorry, I forget their name, it was that long ago!) I do
recall, it was NOT cheap!!
Charles 1974 FJ40

They sell the blue chromate at Caswell.....along with the olive green and the black. They recommend 2 bottles of the blue(fewer ounces in the blue vs. the yellow....you need 2 of them to have more fluid in the bucket).

 

[c2dfj45]

Your results look incredible, they put mine to shame I’m also surprised how well the brightner works, better than I thought and shinier than I could ever get them by polishing the pieces. My only question would be if the brightner works with just white vinegar and salt or you need their solution. In the interest of science and sake of this write up I will purchase it and find out I think it was $40 or so (just checked, $17, not bad). And thank you for sharing the other tips and pointers, did I say how good those parts look!!??

I was pretty surprised at how good things worked right from the start. I was reading about horror stories with trying to get things right and all the issues people had. We really didn't have many. A few isolated things but nothing too major. It's super important not to touch the pieces with bare hands obviously.....oil will do some weird things. I always move my pieces in the zinc bath around.....changing their positions so zinc hits from all sides. We usually run 2 strips of zinc on either side of the parts that are hanging. I try to get the temp of the zinc to around 100 degrees. Seems to work good. We usually start at 90 or so and then as the day goes on it gets warmer.

And of course the air drying with the heat gun......I think that really helps things the most. You can watch them change color once they get heat on them.

Perfect for projects like this:

 

[avicenna110]

I was pretty surprised at how good things worked right from the start. I was reading about horror stories with trying to get things right and all the issues people had. We really didn't have many. A few isolated things but nothing too major. It's super important not to touch the pieces with bare hands obviously.....oil will do some weird things. I always move my pieces in the zinc bath around.....changing their positions so zinc hits from all sides. We usually run 2 strips of zinc on either side of the parts that are hanging. I try to get the temp of the zinc to around 100 degrees. Seems to work good. We usually start at 90 or so and then as the day goes on it gets warmer.

And of course the air drying with the heat gun......I think that really helps things the most. You can watch them change color once they get heat on them.

Perfect for projects like this:

View attachment 2865261

Ok you’re not allowed to post pictures anymore very beautiful and thanks again for all the tips. I’ll post an update incorporating everything I’ve learnt so far here.