Caswell Plating

[mgood]

From my experience, that is two different times, I noticed that the electrolyte seems to need to be replaced or replenished every so often.  I also did heat my electrolyte to 100 degrees.  I also added a brightner solution to the electrolyte.  As for the 5 sq. inches I assumed that it means all the surfaces together. 

[Namerow]

So far, the question of, "What does 'sq.in.' mean?" remains unanswered.  I recall that Steve/nix240 weighed in on this in another thread a few months ago, so it might be worth looking that up.  His results looked first-rate, but I remember him offering the usual caution that, 'Settings depend on your particular set-up, so you'll need to experiment.'

FWIW, here's a link to a very nice electroplating write-up by a talented amateur restorer in California.  He included it as part of a multi-segment documentation of his work on an early-year E-Type Jag.  Guaranteed to consume an entire evening of your spare time...

http://www.mckennasgarage.com/xke/jag_16.htm

[Patcon]

Here is an area calculator from Caswells site

http://www.caswellplating.com/surface.html

They list the tube and ask whether you are plating the inside or not. I assume if you're not plating the inside that is a line of sight thing? Not actually plugging the ends...

Edited May 22, 2016 by Patcon

[nix240z]

set volts to full current max

set amps to what you calculated via surface area

amps will stay the same on display

volts will drop on display

small items will be plated in the .6 -.7 volts range on the display.

calculate one bolt surface area x .14 = amps needed for plating one bolt

do one bolts as a test, skip the copper pipe.

Steve

Edited May 22, 2016 by nix240z

[Patcon]

Thanks Steve

[Namerow]

On 5/22/2016 at 0:36 PM, Patcon said:

Here is an area calculator from Caswells site

http://www.caswellplating.com/surface.html

They list the tube and ask whether you are plating the inside or not. I assume if you're not plating the inside that is a line of sight thing? Not actually plugging the ends...

Just read Steve's reply, which is clear and right to the point.  Good to know.  Note that he's recommending 140mA per sq.in.

I hadn't seen the Caswell calculator before.  It confirms that "sq.in." refers to the total area of the wetted surface of the part(s).

When I referred to the possibility that "sq.in." might have to do with 'line of sight' effects, I wasn't really referring to the case of a hollow pipe or tube.  Instead, I meant that 'sq.in.' might be referring to the 2-dimensional 'face' that a part presents to the zinc as it streams off the anode.  I now know this theory was wrong.

I played around with the Caswell calculator for a while.  Everything is pretty straightforward, except for the case of the bolt.  Here, the calculator proved to be a little more sophisticated than it looks.  It appears to take the area of the threads into consideration (rather than just considering the bolt shank as a long smooth cylinder).  It also appears to calculate on the basis of a hex-shaped bolt head  (rather than just a square head, as the diagram would have you believe).

Looking at your own plating tank set-up, you might want to consider replacing your little zinc sheet with a full-perimeter ring.  This helps to offset masking/shadowing and makes it less likely that you'll need to turn the part(s) during plating to get full coverage.  Even with the 'ring' anode, though, I've found that the surfaces of the part the point 'up' and 'down' (rather than 'sideways') often don't plate properly and I need to re-jig the way the part dangles off its hook.  I've been using a product called 'Moss Boss' for my anode.  It's intended use is to control of moss growth on wood-shingle roofs (applied as a flashing strip along the roof peak). It comes in a roll that's about 40' in length and 4" wide.  Inexpensive, but you might have to special-order it.

Let us know how you make out.  I'll be re-starting my own plating project tomorrow.  I, too, experienced problems on my last attempt and was so frustrated that I just put everything away.  Since then, I think I've discovered what I was doing wrong and have also gained access to a controllable voltage/current power supply courtesy of Grannyknot.  I'm hoping for much better results this time around.

[nix240z]

just remember, if it was easy then everyone would do their own plating.....

I just don't give up easy and it was a lot of trial and error till it worked with my setup.

small batch I did 

Steve

 

[Patcon]

Namerow

I have seen moss boss and had thought about doing that. I also really need to go to a 3 gallon kit instead of 1 1/2 kit. I was really just trying to make a first stab at it and then figure it out. I will try the power supply again but it will probably be Saturday...

1 hour ago, nix240z said:

just remember, if it was easy then everyone would do their own plating.....

I just don't give up easy and it was a lot of trial and error till it worked with my setup.

I understand but I do the hard work everyday...

I also don't give up easily, but your experience is invaluable. Especially after seeing all the beautiful plating. Also where are you on your car? Have you set the motor yet?

 

[Patcon]

Ok. Today I messed with this some more. Set the Volts all the way up, Amps all the way down cut it on. Tried to crank the amps up and this is all I got without the resistor

 

Added a 1 Ohm 100 Watt resistor, this is what I got

 

Tried just the 1 Ohm resistor and tried to get the current up but no dice. According to this my power supply is bad...

http://forum.caswellplating.com/forum/electroplating-questions/6724-my-power-supply-has-me-confused-can-t-control-current?t=6535

 

Edited May 28, 2016 by Patcon

[Namerow]

1. What is the part that you're trying to plate?
    
2. Can you possibly add more surface area to your zinc anode? Pieces of zinc can be joined together by mechanical means, with a jumper wire for electrical connection, or - preferably - by a solder joint.  Zinc takes solder very well, BTW.

After reading the Caswell forum narrative, I'm inclined to agree that your power supply may be toast.  Nevertheless, perhaps you could try exercising it with a more typical small-resistance load, just to see how it performs.  I've used a double-filament #1157 bulb (front park-t/s or rear taillight) to good effect before I got access to a controllable-volt/amp power supply.  They're surprisingly robust.  Just solder 12" insulated wires onto the shell and end contacts, add some alligator clips and you're good to go.  The cold resistances are 0.7 and 2.5 ohms (altho maybe higher with the filament heated up).

I got my plating project fired up again late yesterday afternoon.  I'm using a vinegar-and-epsom-salts bath rather than the Caswell electrolyte.  I tried one 'big' part (ignition coil mounting clamp) and one 'small' part (brake line hold-down clip).  Surprisingly (to me), the big part was easier to do and plated very nicely (it's about 20 sq.in. and I used about 3A, IIRC). 

The small part has proved to be a lot more challenging.  I had to re-do it three times before I got a decent result.  And I still need to do it a fourth time to try to get it right.  I've confirmed that 0.3A is about right for this application.  The L-shape of this part makes it challenging to get both legs plated and on both sides. 

On Attempt #1, the zinc wasn't really depositing.  I had wire-wheeled the part prior to the acid bath and I now believe that my wire wheel causes problems (it's brass, mounted on my bench grinder).  Maybe it's a burnishing effect, maybe the brass loads onto the part's surface, or maybe my wheel is contaminated with other stuff, I don't know.  I do know that I'm not going to wire-wheel anymore parts before plating.

Before Attempt #2, I took the part pack to clean metal by re-blasting (I'm using ground glass media).  That helped a lot and now, back in the bath, I had plating happening.  Unfortunately, I got greedy and cranked up the current to see what would happen.  The zinc started to turn black.

For Attempt #3, a re-blasted once again.  Current now back to the correct 0.3A.  After ~ 5 minutes I had a fairly good result -- except around the ends.  The part was suspended in the bath using a copper wire hooked through the holes at either end of the clip.  Apparently, the electrical field set up in the part doesn't 'flow' into the small areas at the ends of the clip (i.e. the parts of the clip that are 'outboard' of the holes).  There's a very distinct 'half-halo' boundary around the hole where the plating visibly stops.  For my next -- and, I hope, final -- attempt with this part, I'm going to solder the copper wire to the very tips of the part (on the back side, of course) so that the electrical path comes in the from the very ends of the piece.  I'll let you know how it turns out.

[Patcon]

That's good info. I ordered a new power supply last night. It's 10 amp so it could handle 95% of what I might plate...I tried the 1 Ohm resister I bought to try to get my power supply to adjust but no dice

[Patcon]

23 minutes ago, Namerow said:

I'm using a vinegar-and-epsom-salts bath rather than the Caswell electrolyte

What is your recipe for your electrolyte solution? I need to up my volume and this would be cheaper than buying another 1.5 gal kit