Copy Cad kit

[kenrinc]

Can someone please clarify why there are two sets of instructions in the ver7 plating manual?

On page 100 is a breakdown of the copy cad process where it states specifically: 110degF, agitation, 1qt Zc/CC crystals per 1.5gal of water, 1 amp per 40sq in. 1-4volts., ph5.5 - 6

Then on the next page (103) it has the same table only this time everything is different: 65-90degF, agitation, CC & Zc concentrate, 1-3volts .01 - .02 amp per sq in.

So what is it? 65-90deg @ .01 - .02 per sq in or 110deg @ 1 amp per sq in??

Totally confusing

Ken-

[seanc]

Re: Copy Cad kit

Ken:

The manual has had conflicting information as far back as version 5.

So what is it? 65-90deg @ .01 - .02 per sq in or 110deg @ 1 amp per sq in??

Here's what works best for me: 65-90 deg @ 80-100 mA (.080 - .100 Amp) per sq in. The 25 mA per sq-in is not enough.

I shoot for 70?, but if ambient temperature is already over 70, I don't bother trying to cool it off.

See my album for some of my work:

Zinc parts

Sean

[kenrinc]

Re: Copy Cad kit

Thanks Sean.

I did two brake calipers yesterday and they turned out fine. Adjusted the amp output to 1.7amp on the PS and they look great. Now I'm doing the front's, which are a bit larger, not much but larger. So I took the power up to 2 amp but still end up with dull grey plate. Even going to 3 amp got me the same thing. I'll experiement a bit more tonight.

Ken-

[seanc]

Re: Copy Cad kit

Ken:

How many sq-inches of surface area on your calipers? How many sq-inches of zinc anode do you have?

Don't let your parts exceed the surface area of the anodes.

Are you using the "brightener"?

If so, it gets consumed during plating, and you have to add more when parts start looking less "bright" than they did before. It gets consumed faster than you might expect.

If not using brightener, parts will always come out dull grey.

Sean

[kenrinc]

Re: Copy Cad kit

I think it's a combination of things. I went back to doing small parts again and was able to get it to work. Part of the issue is that I'm not getting a good connection to the part via the wire wrap. I tried using aligator clips and that fixed it when doing small parts. Did a few more small parts and it's still working well.

Now that I look back I think I'm beyond the capacity of my PS which is one of the classic digital 3a jobbers.

Can I do the copy/cad stuff with a car battery ? I'd need to reduce the voltage that's for sure ...

Ken

[seanc]

Re: Copy Cad kit

Ken:

It doesn't require a real tight connection, just a patch big enough to carry the current. I never wrap anything, just hang the parts on a hook of copper wire.

Your 3A PS is good for 40-45 sq-inches at most. I suspect your calipers are far larger than that.

A battery would give you lots of current, but how would you control it? You need to control the total current first. Then the voltage will fall into in place at whatever it needs to be. That's why a constant current power supply works best.

Sean

[kenrinc]

Re: Copy Cad kit

Sean, I think your right on. I'd guess the calipers are probably around 110sq in roughly. I wrapped a 8.5" x 11" piece of paper around them and that fits well although that doesn't account for all the internal passages. I may move up to a 10a jobber and see how that works.

Thanks!

Ken-

[seanc]

Re: Copy Cad kit

Ken:

You could try doing half the caliper at a time, turning it over for the second half. I've done large parts this way and it works. It leaves a parting line where the 2 halves overlap, but most of it disappears if you acid bright dip afterwards, and yellow chromate will hide more of it, but it will still be slightly visible.

Doing half at a time w/3 amps gives you @55 mA/sq-in. Thats a little low, but might work good enough.

110 sq-in. is still quite a bit more than your anodes size too.

I'd still recommend you work out the issues with smaller parts first.

Sean

[kenrinc]

Re: Copy Cad kit

Sean,

Everything is working for the smaller stuff. I tried doing the calipers one side at a time and although it does work what happens is that this blue green film forms during the time the other side is in. Once I'm done doing one side I have to mask off and reblast the other side because the entire time I was plating the one side it was getting green and rusting on the other side ! You can actually watch it rust while you plate the other side! Just too much trouble.

10a should be enough to do the whole thing by itself. I'll let you know how it goes.

Ken-