Please Take the Time and Help!

[weller]

Hello to anyone who is willing to help:

Though I am a pretty godd restorer, I am a complete duffus when it comes to plating and hence if anyone can answer my questions below on what I need to order it woudl be highly highly appreciated as I am not getting any help anywhere.

1. I will be zinc plating nuts and bolts mostly although two large pieces are a shock absorber coil, 12" long, 1" diameter. The other part is a hollow tube 1/4" diamater and 36 inches long approx. What type of power supply do I need to purchase 3 amp? 5 amp?

2. The way I understand it is that teh anode is connected from teh power supply to the part and another anode to the zinc plate. Is this correct? Although I will be purchasing the copy cad zinc kit, it does not come with anodes or the power supply, so as a beginner I would appreciate if someone coudl let me know what exactly I need to purchase. How many anodes etc..

3. Can we use more than one anode from the power supply to the part being zinced? If so why does it speed up the process.

4. How do I know how much current to induce from the supply and for how long?

5. If teh zinc brightener is added to the solution does it remain there or does it dilute itself away. I need to know in case some parts require the matte finish as opposed to bright. Basically if we add brightener to the solution is it too late to go bacK?

Look I know the above questions are probably really stupid sounding for most of you, but please understand me I am in deep anguish here and I have four weeks to complete a project.

Thanks, Pat

[seanc]

Pat:

I am a complete duffus when it comes to plating

You're in good company! We were all dufuses when we first started!

1. What type of power supply do I need to purchase 3 amp? 5 amp?

It all depends on surface area of the part. Your tube alone would require almost 4 amps. Would need more info about your coil to say. What's the diameter of the wire itself? How many individual "coils" in the overall length? Is 1" the inside, or outside, major diameter?

2. The way I understand it is that teh anode is connected from teh power supply to the part and another anode to the zinc plate. Is this correct?

No. "Anodes" are the zinc plates, and they DO come with the kit. The parts you're plating are the "Cathodes". The 2 should never touch.

3. Can we use more than one anode from the power supply to the part being zinced?

Yes, but see #2 above. The "anode" is NOT connected to the part.

If so why does it speed up the process.

It doesn't. You simply have to have enough anode to plate the part. ie, the immersed surface area of the anodes must be equal to, or greater than, the surface area of the part you're plating.

eg, your tube above has approx 28 sq-in of surface area, you'd want at least 28 sq-in of anode, or more, to properly plate it.

With odd shaped parts, it can be beneficial to have additional anodes placed at strategic locations to get into deep corners and recesses.

4. How do I know how much current to induce from the supply and for how long?

See #1 above. Surface area of part x .14 amps. 20 minutes puts down approx 0.001" of plate. Less time = thinner plate.

5. If teh zinc brightener is added to the solution does it remain there or does it dilute itself away.

It gets "consumed" during plating, and has to be replenished every once in a while. How often just depends on how many parts you plate.

If you want to plate "non-bright" parts, but your electrolyte still has free brightener in it, you'd have to keep plating bright parts until it's gone, or filter the electrolyte, which removes the brightener.

Sean

[weller]

Sean: Many sincere thanks for your help. Seriously. Much appreciated. I have done some further research in investigating the part sizes, and the largets parts are the following:

Coil 1: 7 1/2" long, 1 1/2" outside diameter, 1/4" thickness each coil strand
Coil 2: 12" long, 2 1/2" outside diameter, 1/4" thickness each coil strand

- Will the 5 amp rectifer be sufficient?
- Does the Copy Cad kit have sufficient anodes (zinc plates) to carry this job or should I purchase extra?
- I am looking at purchasing the 3.5 gallon kit, although it seems excessive. Can't I simply purchase the smaller kit and have a wider plastic tray that covers more area as long as the parts are immersed?

If you could just dot down what it is I need to purchase it woudl be of great help! .

Pat

[seanc]

Pat:

- Will the 5 amp rectifer be sufficient?

Still not enough data to say entirely. See below.

Coil 1: 7 1/2" long, 1 1/2" outside diameter, 1/4" thickness each coil strand
Coil 2: 12" long, 2 1/2" outside diameter, 1/4" thickness each coil strand

The 7 1/2" & 12" OAL dimensionss are usless.

You have to think of it as a long straight piece of wire that hasn't been "wound" yet. How many time does each coil wind around?

eg, take your 12" long coil (probably the larger of the 2): the circumference of the "strand" is @ 0.785". Each individual "coil" is approx. 7.46" long. But how many "coils" total? Gotta multiply the number of "coils" by the length of each coil, then by the wire circumference:

if it were 10 coils, you'd have 74.6" long wire x .785" gives 58.6 sq-in., x .14 amps = @ 8 amps!
if it were 6 coils, you'd have 44.8" long wire x .785" gives 35.1 sq-in., x .14 amps = @ 4.9 amps.

- Does the Copy Cad kit have sufficient anodes (zinc plates) to carry this job or should I purchase extra?

Off hand, I'd say just enough. But again, only you can determine what the largest part you'll ever want to plate is, then get enough anode to equal that size.

- I am looking at purchasing the 3.5 gallon kit, although it seems excessive. Can't I simply purchase the smaller kit and have a wider plastic tray that covers more area as long as the parts are immersed?

3.5 gal? I only see the 3 gal. kit.

I use a 3 gal. setup, your 12" coil would barely fit the tank, and would probably still need some extra anode run down the center.

How do you plan to do a 36" long tube?

Remember we're talking about electricity here, and electricity will always take the path of least resistance. The more space you get between your anodes & your part, the more consistent the plating will be.

eg. lets' say you had a part 4" in diameter, and the closest surface was only 1" from the anode. Well, that 1" surface will get most ALL the plating, the side 5" away will get almost NO plating. In a case like this, you'd want to rotate the part every so often so it got even exposure.

How well the interior of the coil would plate depends on how closely spaced the coils are. It it were a tension spring, w/closed coils, you'd need to "open it up" by pre-tensioning, or run an aux. anode down the center.

OTOH, having said all that, I personally would not plate a suspension spring. You'll get hydrogen embrittlement of the spring, and it may fail due to stress fractures long before it should. A spring that flexes a lot under heavy load is NOT the best candidate for plating, IMHO.

Sean

[weller]

Sean: I ran the math and I am in trouble! Well for starters the bike will not be used it will go in storage or a museum once I am finished so I am not worried about the load and the brittle effect, though I agree with you.

Largest coil has 21 wrap arounds therefore this gives me:
21 x 7.46" x .785 x .14 = 17 freegin amps! How m,uch will the rectifier cost. Wow!

Next question. I imagine the rectifer is like a battery charger and emits current with two leads: 1 positive the other negative. When your parts are in the bath (electrolitic solution) does the positive lead attach to the part while it is immersed and the other lead from the rectifer (negative) go to the zinc plate or anode? Help me out here I still have not gotten the manual!

If the above is the case, can I not simply just use a car battery charger an set it to high. It has two leads and gives off 30 amps doesn't it? What kind of problem would this cause if I was only doing small parts such as bolts.

You mentioned two intersting points about having to move around parts during the process. Clearly with the power off correct? I imagine you do not want to place any part of your body in the solution when it is running.

You stated that I may have to slide in one pice of an anode inside the coil. I imagine then that the zinc anode can be cut to size and a lead attached to it.

Regards, Pat

[seanc]

Pat:

Next question. I imagine the rectifer is like a battery charger and emits current with two leads: 1 positive the other negative.

That's where the similarity ends.

+ lead goes to anodes, - lead goes to the part being plated.

If the above is the case, can I not simply just use a car battery charger an set it to high.

No, see below.

It has two leads and gives off 30 amps doesn't it?

Yes, but a battery charger operates at a set voltage, w/free running current. For plating you need the opposite: Set current w/free running voltage.

Plating is current dependent. ie, it is "current density" that counts (amps per sq-in). For your coil, it's not an "at least" 17 amps, it's "exactly" 17 amps . No more, no less (+/- a few percent).

A typical battery charger is not controllable in this manner.

What kind of problem would this cause if I was only doing small parts such as bolts.

You have no control over the current, so no control over the plating parameters. A 30 amp battery charger would produce badly burnt plate.

It would require some sort of added external control so you could adjust the current to what is needed by the size of the parts you're plating.

Clearly with the power off correct? I imagine you do not want to place any part of your body in the solution when it is running.

Depends on the part, some can be rearranged w/out shutting power off. Rubber gloves are a must if you're going to get your hands or fingers in the liquid.

I imagine then that the zinc anode can be cut to size and a lead attached to it.

Correct, but the lead itself has to remain outside the electrolyte. Only zinc anode should be immersed.

If you're only going to do this a few times, for "show", I think you'd be better off w/one of the brush plating kits.

Sean

[weller]

Sean:

Think I got you scared there when you recommended I use the brush plate. No worries, I won't blow anything up. It is just that I have not seen a kit or even read any manual so I am slightly apprehensive and anxious.

Spoke to someone at a shop today and you were right about the coils. If I plate them using "current method" they will go brittle on me and the fisrt drop they will crack in a million pieces. They said something about them having to be stripped, defibrilated or something and then baked. Needless to say they will zinc plate the larger parts (coils and all). This leaves me to focus on working with much more manageable pieces such as a wide variety of small nuts and bolts (M4 to M11 size) and some other smallish parts.

Therefore I will definetly be reducing the size of the copy cad kit to about 3.5 gallons but will stay with a 25 amp rectifier as this may assist for future use.

Will start off slow with some sample runs and will let you know eventually when I get worked up.

Thank you sincerely for your comments and assistance as well as guidance. I have learned much from you in the last few days and the fact that you took the time to instruct this novice can only be thanked by me returning the favour one day.

Best to You, Pat

[seanc]

Pat:

Think I got you scared there when you recommended I use the brush plate.

Not at all. Has nothing to do with power.

Brush plating is a simple alternative to "full immersion". You simply paint the plate on as you would with real paint brush. There's no calculating surface areas or total current requirement. A simple method for doing large parts w/out the complexity or expense of an immersion system.

Good luck, have fun & keep us informed!

Sean