For the home plating specialist

[conbs]

I have read quite a bit on plating and gathered a bunch of pieces together to build my set up, but still have not had time to plate a thing. Here is what I understand.

First, I assmue we are still talking about vinegar and sugar solution. That is what I am going to use. The solution is important because it has limits regarding "throwing power" which I understand to be its ability to move zinc ions from the source to the piece you are plating. As others have noticed, if you leave your zinc source sitting in your vinegar solution, it will dissolve. That is good, because at the end of the day the ions that go on your piece always come out of solution. But, once the dissolve zinc is plated out of the solution, its ability to replenish the bath will be reduced.

In terms of correct voltage/ amperage, I understand that the vinegar solution limits you to between 1 1/2 to 3 volts, but it may be the qualities of zinc ions that make that the correct range. Irrespective, that is what I am aiming to hit. I have meters to measure volts and amps, so I will be able to report what I find. If I recall correctly the amps should be adjustable to provide correct amperage based on the surface area of the piece you are plating figured at about .1 amp/ sq inch. Bigger piece requires more amps. Smaller piece - the amps must be lowered to get the best results.

If your amperage or voltage are outside of those ranges, I understand it will cause less than optimum plating results. Bubbling, black deposits, etc., and including hydrogen embrittlement. In the end, just about any wall charger of any size will plate zinc in vinegar solution. As I understand it - with absolutely no experience - aiming at the correct volatage and amperage range will improve your results. That's what I am trying to do. Hope this helps. If anyone disagrees, I hope you will straighten me out.

[Wilf]

conbs,

I think your overview is right on the money.

I will add one note with respect to the depletion of ions in the solution. When the ions get used up faster than new ones can dissolve you get bubbling at the part being plated. When this happens, you are breaking down the acid which in turn reduces its capacity to dissolve more zinc. Eventually the solution becomes useless and a new batch must be built. Trying to increase the voltage or the current is counter-productive at this point.

Using as much zinc surface area as possible and using as low a voltage/current as practical will help to balance the amount of zinc ions being used to the rate at which new zinc can be dissolved.

Wilf

[conbs]

Wilf,

From what I have read, it appears that when bubbling starts to happen, reducing the amperage and/or voltage should put less "pressure" on the solution so it will not be ruined. Cranking up voltage or amperage when bubbling starts is exactly the opposite of what you want to do. The eletrons have to go somewhere and if they can't be used for plating because there is not enough throwing power in your bath, they start disassembling the components of the bath. I think this is true for solutions other than our beloved vinegar, however I understand that cyanide baths are the least susceptible making them attractive for commercial platers. Cyanide is way more dangerous than most of us want to tackle, just to get rid of some bubbles. Hope this helps.

[pc50fixer]

Thanks for the input Wilf. Once I get my 50watt (500 ohm) rheostat ordered and my hands on some degreaser, I'll give this a go.

I did go one step further with my zinc plates. When I was drilling holes in them for the copper wire, I saved all the drill shavings for a little extra charge for my solution. Looking forward to the final outcome! My main workshop is unheated so I like smaller projects like this that I can do in my basement on the bench. I should collect more old mopeds for this exact reason!

[pc50fixer]

Is the recipe and quanties of sugar/epsom still the same?

Epsom Salts - 100gm/liter
Sugar - 120 gm/liter

I do not have a bead blaster so I am wire brusing with a small brass dremel tool all the little bits to remove the corrosion. Should I use acetone as a degreaser bath prior to dipping in the zinc bath? One other thing, since many of the pieces I am doing are nuts and bolts, do I need to mask off the threads of the bolts? Would nuts and bolts gain any significant amount of coating to make them un-threadable? Minimum dip time for these little bits should be 5minutes correct?

[Wilf]

I still use the same recipe, and I use acetone as a degreaser.

There is no need to mask the threads as the thickness of the plating is very small compared to the thread slack.

You will be able to judge the timing when you look at the result. It's pretty hard to overdo it, and if it's not plated for long enough you will notice it.

Wilf

[pc50fixer]

great. Thanks. Masking would have been a major pain.