Too much brightner?

[kenrinc]

I've been having this problem for a couple weeks where my copy cad/zinc bath doesn't seem to be working well anymore.

Basically the plate doesn't seem to ever cover the entire part; almost like it only plates in certain areas and no matter how you adjust the current it won't plate in those areas or plates a dull grey plate. Almost like it only plates near the anode. The parts are flat out clean. I sandblast, rinse and go into the bath. Sometimes I do a pickle but not always and either way it doesn't seem to make a difference. The areas that do plate aren't that bright and I have added brighter to see if that was causing it. Doesn't seem to do anything. I sandblast my anodes and wash before using.

In my haste, I may have added too much brighter and am not sure what to do if I did. How can I remove it? I'm considering just ordering a new bath but was told it will last forever.

Appreciate any help

Ken-

[jimcarry]

If you think you have added to much brightener you can simply filter it out using a submersible pump and filter that should have come with you kit then add new brighteners to your bath
what size kit did you purchase

[seanc]

Ken:

In my haste, I may have added too much brighter and am not sure what to do if I did. How can I remove it?

Filter it.

Cheap but labor intensive method: use coffee filters. If you have much sedimentation in your electrolyte, the filters will plug up quickly. I got @ 1 quart per filter before it stopped flowing effectively.

Better method, costs a few $: go get an activated charcoal water filter cartridge (the type used to filter water to refrigerators w/cold water taps). Plumb a plastic tube from an aquarium pump to the filter inlet. Hang the filter above your tank, immerse the pump in the tank and turn it on. The filtered electrolyte simply dribbles back into the tank.

It takes a LONG time, but since you're not manually attending to it, let 'er run for a few hours. If you agitate the electrolyte at the same time, stirring up the sedimentation, the electrolyte will eventually clear up. By this time, the sedimentation AND the brightener are mostly gone.

Or ... you could plate it out with a dummy. But this is wasteful of anode.

Sean

[kenrinc]

I've been told the bath lasts forever (within reason) but anything I try to plate just turns out dark grey, even with miniscule amounts of power. I put a small bolt in there calculated at roughly .5 sq in at 50ma and it just turned grey. Turning down the power didn't change anything and turning it up just frothed the electrolyte with nearly the same only burnt plate. I assume it's too much brightner but I have no way to verify..

Last night I hooked up a copper tube to "plate out" what I saw as a problem. Ran it for a couple hours. The plate was grey/black and grainy. I had the current perfectly set for the sq in calculated so I know it isn't too much power. I think I'm just going to buy another batch of electrolyte because I'm up against a deadline.

Do the annodes ever go bad? How long can you use them for?

Ken-

[seanc]

Ken:

There's many possibilities to consider:

First, I've also heard that the electrolyte lasts indefinitely, but the brightener does not. It gets consumed during plating, so you have to replenish it every so often, whenever the parts start to come out dull again. Until now, I've never heard that you can add TOO much brightener, so I can't help you there.

I used the recommended 1 teaspoon per gallon to begin with, and when I notice parts not plating as bright, I just add another half teaspoon. So I guess I've never over-brightened.

How many quarts/gallons of electrolyte do you have and how much total brightener have you added?

You say you've got a bolt that's .5 sq-in. That must be a tiny bolt. Surface area of bolts can be quite deceptive. My initial "guesses" turned out to be way less than the actual calculated surface area.

For instance, a 1/4" bolt, 3/4" long, has 1.75" surface area. My initial "eyeball" estimate was no more than 1", so I was way off.

If you're getting lots of "frothing" from something that small, then that's WAY too much current. Even something as small as 2 sq-in will only give off light fizzing.

Another possibility here is that you don't have good electrical contact with the bolt. If the connection isn't good, then most of your current is going into plating the hanging wire, and not the part. How have you got it wired? Is your connecting wire in the electrolyte? How did the wire plate?

It's possible that your electrolyte has been contaminated with someting else too. Anything unusual happen to it in the past?

Anodes shouldn't "go bad", but they do get consumed over time. As you plate more over time, the anodes will get progressively thinner, and ragged around the edges, as the zinc molecules are pulled off. They'll eventually disappear if you let them. I never do anything with my anodes except rinse them off in fresh water after a plating run. I've even let them sit in the electrolyte for 3-4 days, and they still plate fine.

I did a bunch of tests early on, using different current densities, with and w/out brightener, to see what worked best. We were discussing it on another thread too, and the links are here:

http://forum.caswellplating.com/electroplating-questions/4770-copy-cad-zinc-trouble.html#post24467

Do your results look anything like mine?

Sean

[kenrinc]

Sean,

I do think that I need better wiring (thicker). I'm just using standard test cables and normally they just connect to the wire. For the caliper I think I may actually connect it to the part. Is it better to fully emerse the part wire in the electrolyte or have it connect to a wire that connects to the part? It seemed to plate better with the clip directly in the electrolyte.

Something happened last night when I tried to add some top up water to the bath: when I poured the dist water in the bath, it "gelled" up. It was weird. Almost like egg on the top of soup. I mixed it around and it seemed to go away but left a haze in the tank. I've ordered more electrolyte. Wish I could figure out what the problem is.

Ken-

[seanc]

Ken:

If your caliper is as big as I'm estimating, and your'e using @ 20 amps, you'll need a good heavy gauge wire. At LEAST 12 ga., and it will need to make good contact with the caliper.

Is it better to fully emerse the part wire in the electrolyte or have it connect to a wire that connects to the part? It seemed to plate better with the clip directly in the electrolyte.

It shouldn't make any difference to plating, as long as the connections are tight. I have my clips outside the electrolyte, but as long as they're clean metal, they should work inside the electrolyte as well. They'll simply get plated with the part, and you'd have to rinse them well afterwards.

The problem is, unless the wire insulation is 100% sealed, electrolyte will wick up inside the stranded conductor. You'll never be able to rinse it out, and the wire will soon corrode and fail.

Something happened last night when I tried to add some top up water to the bath: when I poured the dist water in the bath, it "gelled" up. It was weird. Almost like egg on the top of soup.

That's definitely not normal. I add water every so often to make up for evaporation, and have never had that happen. Always blends right in.

Have you asked Caswell tech support?

Sean

[kenrinc]

Sean. Figured something else out. I cannot hook up multiple annodes in series (or parallel) without the power supply switching out of CC mode. If I hook up all the annodes (with 12 gauge wire) the power supply just sits there at .03 amp and won't do anything when you turn the amp dial. If I connect up to only one of the annodes it works fine. Anytime I try to hook another up in series, the power supply just won't dump current. I'm guessing it's a resistance thing but what the hell? How the hell am I supposed to plate when I can't even use my annodes?

ken

[seanc]

Ken:

This is typical of some power supplys. They will not operate into low resistance loads. As you add more anode surface area, you're decreasing the resistance within the electrolytic "cell" (which is what your electrolyte tank is).

Put a 1 ohm high wattage resistor in series with the positive lead and it should work.

Sean

[kenrinc]

Ah. Got it. I've got a 1 ohm, 10 watt unit I can try. Seems like a small wire for such large current though. I've got some pics of what I've gotten so far, I'll post them later. Since it looks as if I only had one or two anodes hooked up for any span of time it would plate on one side only and then only on high parts of the part. I'm still dumbfounded on how to get a better idea of the surface areas involved. 12amp seemed like the right amount of current but after looking at it again it might be too much as the plate was rough in most of the areas it went down.

It's funny, I've used the bath to plate a plethora of smaller parts yesterday with no problems at all! Large parts are a definite learning experience for me!

Ken-