Author Topic: Cheap constant current controller for electroplating  (Read 2133 times)

0 Members and 1 Guest are viewing this topic.

Offline spurlock

  • Full Member
  • *
  • Posts: 43
Cheap constant current controller for electroplating
« on: September 19, 2018, 06:27:04 pm »
I recently acquired a bike that needed some hardware replating and after looking at do-it-yourself plating options like this (https://yamaha-enduros.com/index.php/forum/how-to-write-ups/187-do-it-yourself-zinc-plating-process?limitstart=0) and reading about the Caswell zinc plating kit it was clear that to get good results it's necessary to precisely control the current used for electroplating. Too little and the plating does not happen, and too high produces rough dull plating.

I ended up buying the Caswell system here - https://www.caswellplating.com/electroplating-anodizing.html?cat=54 Constant current power supplies are really pricey but I came up with a cheap home brew version and thought I would share it here.

After experimenting with various batteries and light bulbs to control current, I found an $8.26 adjustable controller on ebay which I used to adjust current from an old computer power supply. First, to make a computer power supply operate you just need to connect any green wire with any black wire. That will turn it on. Then it will produce various voltages from 3.X to 12 in the various leads.

Here is the ebay controller I used:
https://www.ebay.com/itm/12A-Adjustable-LCD-Buck-Power-Supply-Module-Onstant-Voltage-Constant-Current/312032536120?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I am running the controller off of the computer power supply's 5 VDC output, although the 12V taps would work fine as well. The 3.3V taps are too low for the controller to use. To make this particular controller produce constant current you first need to back the current adjuster all the way down, connect the positive output lead to the zinc anodes in the plating tank and the negative lead to the parts to be plated, then begin turning up the current screw until the correct amperage appears in the LCD screen.

For zinc plating with the Caswell system the correct current is 0.14 amps per square inch of material to be plated. So first step is to calculate surface area of the parts. Caswell's web site has formulas for calculating areas of common shapes but I just use some geometry and rough estimations and get good results. Below is the power supply, ebay controller, and plating tank doing a batch of case bolt heads.



I did most all of the fasteners, engine mount bolts, axles (heads only) chain adjusters etc. on my latest bike. The results-











There's more to the job than I've presented here so if anyone would like more detail I'd be happy to add more. As with so many things, preparation of the parts beforehand is key to success.

-Bill
1975 Honda CB125S, 1989 Honda NX250, 1989 Honda GB500, 1989 Honda CB-1 400F, 1997 Honda Dream 50

Offline jgger

  • Expert
  • ****
  • Posts: 1,367
Re: Cheap constant current controller for electroplating
« Reply #1 on: September 19, 2018, 07:54:47 pm »
Very nice results, I have often thought about a setup like that. What was the total investment if you don't mind me asking?

Also the time factor (in the tank/solution) is that critical?
"The SOHC4 uses a computer located about 2-3 ft above the seat.  Those sometimes need additional programming." -stolen from  Two Tired

Offline spurlock

  • Full Member
  • *
  • Posts: 43
Re: Cheap constant current controller for electroplating
« Reply #2 on: September 19, 2018, 08:51:05 pm »
I got the 1.5 gallon kit @ $219 plus the ebay Chinese current controller for ~$12 shipped. I had the power supply from an obsolete computer. I usually take them out and save before recycling the computer.

The plating process is basically prepping the parts with a wire wheel or glass bead blasting if available, polishing with fine steel wool by hand or by chucking bolts etc. to spin against steel wool in a drill press, rinse in distilled water, soak in heated degreaser solution (part of Caswell kit) for a few minutes, distilled water rinse, submerge in plating tank with aquarium pump (included) agitation for average time of 20 minutes for a 0.001" thick plating. At the end dip in distilled water and dry. Buff with 4/0 steel wool if needed to polish any dull spots.

Not cheap but it sure is fun to put that sparkling hardware back on the bike!

-Bill
1975 Honda CB125S, 1989 Honda NX250, 1989 Honda GB500, 1989 Honda CB-1 400F, 1997 Honda Dream 50

Offline jgger

  • Expert
  • ****
  • Posts: 1,367
Re: Cheap constant current controller for electroplating
« Reply #3 on: September 19, 2018, 09:14:30 pm »
It doesn't sound cheap, but it sounds like a perfect job for someone like me that has been known to get stuck on anal! ;)

I have heard of people using anything from a trickle charger to old cell phone chargers. Thanks for the info.
"The SOHC4 uses a computer located about 2-3 ft above the seat.  Those sometimes need additional programming." -stolen from  Two Tired

Offline RAF122S

  • I feel like a very very
  • Really Old Timer ...
  • *******
  • Posts: 7,859
  • SOHC4 member # 2605
Re: Cheap constant current controller for electroplating
« Reply #4 on: September 20, 2018, 12:24:32 am »
Do you chromate the zinc plated parts? It makes them much more weather resistant.
David- back in the desert SW!

Offline 05c50

  • 05c50
  • Hot Shot
  • ***
  • Posts: 747
    • Classic Motorcycle Solution
Re: Cheap constant current controller for electroplating
« Reply #5 on: September 20, 2018, 05:39:00 am »
So, you're at it again Bill. Thanks for the write up and doing all the leg work for us. The parts that you did look great, but don't keep us guessing, what's the bike you're working on, and don't forget, we like pictures!. ;)

.............Paul
Wear a helmet,the life you save may be your own.Ask me how I know.               CB650C,CB550F,GL1000,CB750A

Offline spurlock

  • Full Member
  • *
  • Posts: 43
Re: Cheap constant current controller for electroplating
« Reply #6 on: September 20, 2018, 07:11:48 am »
Do you chromate the zinc plated parts? It makes them much more weather resistant.

I have experimented with dipping in Caswell's blue/clear chromate immediately after plating but have not had consistent results yet. As you say it is supposed to retard dulling and corrosion in the future. Still tinkering with it....

-Bill
1975 Honda CB125S, 1989 Honda NX250, 1989 Honda GB500, 1989 Honda CB-1 400F, 1997 Honda Dream 50

Offline spurlock

  • Full Member
  • *
  • Posts: 43
Re: Cheap constant current controller for electroplating
« Reply #7 on: September 20, 2018, 07:40:37 am »
So, you're at it again Bill. Thanks for the write up and doing all the leg work for us. The parts that you did look great, but don't keep us guessing, what's the bike you're working on, and don't forget, we like pictures!. ;)

.............Paul

Hey thanks Paul! The bike is a 1997 Honda CB50V aka Dream 50. I'll write up a post w/lots of pics in the "other bikes" section soon. In the meantime here's the little rascal.



-Bill
1975 Honda CB125S, 1989 Honda NX250, 1989 Honda GB500, 1989 Honda CB-1 400F, 1997 Honda Dream 50

Offline 05c50

  • 05c50
  • Hot Shot
  • ***
  • Posts: 747
    • Classic Motorcycle Solution
Re: Cheap constant current controller for electroplating
« Reply #8 on: September 20, 2018, 10:32:59 am »
Nice........as usual it looks great! Is it one of those "I sure would like one of those......." or did you just happen to stumble upon it?

......Paul
Wear a helmet,the life you save may be your own.Ask me how I know.               CB650C,CB550F,GL1000,CB750A

Offline spurlock

  • Full Member
  • *
  • Posts: 43
Re: Cheap constant current controller for electroplating
« Reply #9 on: September 20, 2018, 10:53:08 am »
Nice........as usual it looks great! Is it one of those "I sure would like one of those......." or did you just happen to stumble upon it?

......Paul

Thanks Paul. Just finished posting the whole story here: http://forums.sohc4.net/index.php/topic,174243.0.html

-Bill
1975 Honda CB125S, 1989 Honda NX250, 1989 Honda GB500, 1989 Honda CB-1 400F, 1997 Honda Dream 50

Offline Bootsey

  • Hot Shot
  • ***
  • Posts: 383
Re: Cheap constant current controller for electroplating
« Reply #10 on: September 20, 2018, 08:59:20 pm »
Great way of recycling & impressive results, thanks for sharing! Do you happen to have any photos of the hardware that has been plated, immediately as it comes out of the plating solution, prior to polishing?

Offline BobbyR

  • Really Old Timer ...
  • *******
  • Posts: 12,367
  • Proud Owner of the Babe Thread & Dirty Old Man
Re: Cheap constant current controller for electroplating
« Reply #11 on: September 21, 2018, 06:30:03 am »
Great looking Bike and nice write up! Thanks for sharing.
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline RAF122S

  • I feel like a very very
  • Really Old Timer ...
  • *******
  • Posts: 7,859
  • SOHC4 member # 2605
Re: Cheap constant current controller for electroplating
« Reply #12 on: September 21, 2018, 06:46:56 am »
Thanks for sharing that info, I have one on the way as I have several old supplies I am turning into power supplies for a few different projects. I have been wanting to setup a zinc electroplating system and this helps solve one of the expenses I was looking at previously. I recently ordered a 99% pure zinc ingot and a bag of Zinc Sulfate from Alpha Chemicals.
David
David- back in the desert SW!

Offline spurlock

  • Full Member
  • *
  • Posts: 43
Re: Cheap constant current controller for electroplating
« Reply #13 on: September 21, 2018, 07:20:50 am »
Great way of recycling & impressive results, thanks for sharing! Do you happen to have any photos of the hardware that has been plated, immediately as it comes out of the plating solution, prior to polishing?

Thanks, the bolts and hardware pictured above were pulled right out of the plating tank, given a distilled water spray and dip, then blown dry with compressed air, no other treatment. Occasionally a part will come out with a slight dull grey area which buffs up easily with a quick wipe of 4/0 steel wool.

-Bill
1975 Honda CB125S, 1989 Honda NX250, 1989 Honda GB500, 1989 Honda CB-1 400F, 1997 Honda Dream 50

Offline spurlock

  • Full Member
  • *
  • Posts: 43
Re: Cheap constant current controller for electroplating
« Reply #14 on: September 21, 2018, 07:48:40 am »
As I mentioned in the first post, there is a pretty comprehensive set of instructions for making up a home brew plating system at this site:
https://yamaha-enduros.com/index.php/forum/how-to-write-ups/187-do-it-yourself-zinc-plating-process?limitstart=0

Lots of enthusiastic comments and good results there, the thread goes on for 11 pages! I was leaning toward setting up that system but decided I would rather just pay Caswell the money and go with a sure thing rather than having to experiment.

-Bill
1975 Honda CB125S, 1989 Honda NX250, 1989 Honda GB500, 1989 Honda CB-1 400F, 1997 Honda Dream 50

Offline RAF122S

  • I feel like a very very
  • Really Old Timer ...
  • *******
  • Posts: 7,859
  • SOHC4 member # 2605
Re: Cheap constant current controller for electroplating
« Reply #15 on: September 21, 2018, 11:02:22 pm »
Caswells is offering free shipping through Sunday on plating or buffing kits and few other things...fyi
David- back in the desert SW!