Caswell Plating

[Namerow]

Steve:

 

What are you using for your bath heaters and temperature controllers?

[Patcon]

Ok, it's been a year and it's time to hit this again. I worked on my plating setup today and tried to do some plating...I was unsuccessful

I am using this power supply that I purchased from another forum member with some Caswell heaters. I haven't run a full test but the power supply seems to working properly but I can't get my current up high enough...

Sorry about the rotation, they show horizontal on my laptop until I add them here. The wire I'm using and the aquarium pump from Harbor Freight. The wire came from Michaels I believe. I thought the brass wire might have been painted but I have the same issue with the copper wire.

Here is the current layout. Crock pot with SP degreaser in it on high. An acid tank in the next bucket after the power supply. The plating tank is this white bucket. Then I have an extra spot if I need it, then the yellow chromate tank in the 1 gallon bucket.. In the plating bucket I have the aquarium pump, the temperature sensor, the heaters and opposing zinc plates.

I have done some reading and evidently the plating tank has very low resistance across it so the power supply doesn't want to raise the current. I added a 12v automotive bulb but still couldn't run the current up any higher than 0.7 Amps. Not nearly enough for my 5" copper pipe test piece. If I turn the voltage up any more I smoke the lamp. I also tried adding a regular 120v 60w bulb in series but again could raise the current up...

Have any of you other guys had this issue with your power supply? I ordered a 1 Ohm 100 watt resister off Amazon. I hope that will get me going...

@grannyknot @motorman7

 

Edited May 21, 2016 by Patcon

[motorman7]

Re: HyElec HY3005E

To use this unit you need to turn the voltage knobs totally clockwise which allows the voltage to vary to maintain the amp or current setting. Use the current knobs to fine tune the amperage setting. 

 

Got this info off the Caswell sight.  Not familiar with that Power Supply.  Sounds like if you turn the voltage knobs fully clockwise you will be able to adjust the current.  You must be able to adjust the current with the power supply current knobs to plate correctly.  Low current for small parts, more current as part size increases.  See if the above works for you. 

[Patcon]

I did try that, multiple ways. With the voltage all the way up, which should make the current adjustable and constant I could only get  0.7 amps.

Motorman7

What power supply are you using?

[motorman7]

Also, after the plating tank, I spray with DI water to clean off plating solution, then dip in Blue Chromate for 30 seconds before the yellow chromate.  Blue chromate helps with the rainbow effect and and also helps the yellow chromate to stick better.  After yellow chromate I rinse in bucket of warm water then dry with my wife's blow dryer on high heat for about a minute.

[motorman7]

BK Precision 1621A

0-18V 0-5A Digital Display DC Power Supply

Brand:	BK Precision
Model No:	1621A
Our Model No:	1621A
Condition:	I have this

[motorman7]

The voltage usually sits pretty low.....close to 1 volt.  current to average size part like an engine bay lamp is 3 Amps.

[Patcon]

Thanks

 

[Namerow]

12 hours ago, Patcon said:

Ok, it's been a year and it's time to hit this again. I worked on my plating setup today and tried to do some plating...I was unsuccessful

I am using this power supply that I purchased from another forum member with some Caswell heaters. I haven't run a full test but the power supply seems to working properly but I can't get my current up high enough...

Sorry about the rotation, they show horizontal on my laptop until I add them here. The wire I'm using and the aquarium pump from Harbor Freight. The wire came from Michaels I believe. I thought the brass wire might have been painted but I have the same issue with the copper wire.

Here is the current layout. Crock pot with SP degreaser in it on high. An acid tank in the next bucket after the power supply. The plating tank is this white bucket. Then I have an extra spot if I need it, then the yellow chromate tank in the 1 gallon bucket.. In the plating bucket I have the aquarium pump, the temperature sensor, the heaters and opposing zinc plates.

I have done some reading and evidently the plating tank has very low resistance across it so the power supply doesn't want to raise the current. I added a 12v automotive bulb but still couldn't run the current up any higher than 0.7 Amps. Not nearly enough for my 5" copper pipe test piece. If I turn the voltage up any more I smoke the lamp. I also tried adding a regular 120v 60w bulb in series but again could raise the current up...

Have any of you other guys had this issue with your power supply? I ordered a 1 Ohm 100 watt resister off Amazon. I hope that will get me going...

@grannyknot @motorman7

 

hmmm.  With all those ripped-apart old cars in the background, that set-up looks a lot like a backwoods still...  Just missing the condensing coils.

 

According to my notes, the typical guide for setting the current is 140mA per sq.in. of part.  One person showing successful results said that he used only 100mA per sq.in., while others have gone as high as 250mA per sq.in.  A lower setting is safe but really stretches out the plating time.  A higher setting speeds things up, but going too high will result in a thick, fluffy, black-ish zinc deposit on the part.  You probably know all that, though.

You mention that your test part is a "5 inch piece of copper".  Is that a 5" length of wire, a 5" length of tube, or a 5" piece of plate?  The reason I ask is this:

It's never been clear to me how "sq.in." should be determined.  In the many DIY plating articles I've read,  No one has ever explained or justified their rationale.  Here's the issue:

Let's say that the part to be plated is a 5" length of 1/2"-diameter thin-wall tube. 

• Ignoring the two end surfaces, the total outside surface area on which the zinc could deposit would be 3.1416 x 0.5 x 5 = 7.8 sq.in. 
• Taking the inside wall surface into account, the surface area approx. doubles to be come 15.6 sq.in.
• However, electroplating is a 'line of sight' process, so maybe "sq.in." means the profile area of the part (i.e. what the zinc anode 'sees' from one side).  In this case, it's 5 x 0.5 = 2.5 sq.in.
• But then, if you have two anodes (i.e. one on either side of the part), the profile area would double and become 5.0 sq.in.
• And if you have a full-perimeter anode lining the inside of your plating tank (as I do in my set-up), then I have no idea what the profile are of the part would be.

So:  Depending on what "sq.in." means, you get four (or five!) different answers, ranging from 2.5 sq.in. to 15.6 sq.in., and the preferred current would be anywhere from 0.35A to 2.2A.

And then there's the issue of creating the correct pH level for the electrolyte (and what it should be, and how much it really matters).

And whether the electrolyte 'wears out' (I've never been quite sure how that would happen).

And whether the electrolyte needs to be heated (some say it's important, some say it makes no difference).

 

All of these issues could affect the correct value of amps per sq.in. of part.  Put together, they could be the reason why people will tell you that achieving good results, 'depends on your set-up'.

 

One thing for certain, though:  Make sure you don't have the polarities reversed for your power connections to the anode and the part.  And don't ask me how I learned that this is an easy mistake to make.

 

I, for one, would be grateful for someone shedding some light on the 'sq.in' mystery.  Maybe the Caswell manual explains this?

 

 

[Martzedcars]

I parted out a 240z and some 280zx's and took about 25 kg to a firm who plates about anything.. i thought its not worth the hassle to do it myself..

[Patcon]

51 minutes ago, Namerow said:

hmmm.  With all those ripped-apart old cars in the background, that set-up looks a lot like a backwoods still...  Just missing the condensing coils

Yeah I have a few too many projects lying around but I am working on that. The thunderbirds were gonna be a restoration project and the Lexus and BMW were being parted out when work got really slow. Too many projects, too little time

 

I have a 5" piece of 1/2" copper tube. Caswell recommends this as a test piece. As for calculating area I was unsure whether you calculate just the exterior or the interior of the pipe too. After plating for 40 minutes and still really not being fully plated, I am assuming that you should double the area

So: 7.865 Squ In @ .15 = 1.179 amps

if it's necessary to double it then 2.358 amps

I could only get to about 0.7 so pretty far short of just the straight amperage needed. I am not sure the area of the zinc plays any part in the area and current calculations...

Also in this part of the world stills are legal for personal use, but it really feels more like Dr. Frankenstein's home lab kit

[Patcon]

Not really any platers in my area and they don't like to mess with little stuff. Also I have had issues getting everything back from the plater, small parts are easily lots in the larger tanks. Easier to just plate in little batches as I get to it and cheaper for me in the long run because I have other cars to work on, obviously...