trying to plate a wheel

[dawghowseproductions]

I want to plate a motorcycle wheel which is 512 sq in.My rectifier is only 250 amps,however i have 2 12 volt marine batteries a shunt and a three hundred amp ammeter which i can get 300 amps by using a #6 copper wire,should work.
However when i add the rectifier and turn it up the power from the batteries goes down.Does anyone know of a one way switch or something like a diode that will allow me to get the power i need to apply the chrome?Thanks Beau

[dadkar2]

This is on the outside fringe of DIY plating. Let me just offer some starting thoughts on the subject.

If you're thinking about chrome plating 500 sq inch items, you'll be sourcing 500 amps, so you need to think about every aspect of the electrical circuit and the connections you will need. This includes:

Size of Rectifiers
You'll need multiple rectifiers. I don't think a battery is going to give you enough life to plate for any length of time at this level of current. A typical car battery will output 50-100 amps for a few minutes, but the voltage may drop to less than 10-11V. But 250-500 amps is going to bring a car battery to its knees rapidly. So to play it safe, you'd need about 10 batteries in parallel. Marine batteries will be better, maybe you'll only need 5 of these in parallel.

Power to the rectifiers from the mains
At 12V output, you'll be pulling 6000 Watts from the mains. At 120V, your breaker will have to be 50 amps and you'll need that #6 wire to connect the breaker panel to your rectifiers. You'll need to make sure your panel and wiring is capable of the additional load. Or get a 220V rectifier, or split multiple rectifiers across both phases of your panel and then you can get away with 30 amp breakers for each rectifier (assuming two 250 amp rectifiers)

Wire and interconnect size
Will need to be hard connections, bolted down. Use large soldering lugs and flow the solder in well. There are other options, but they must be able to handle the current.

I don't advise using #6 wire for carrying much over 80 amps. But you can parallel 6 runs of #6 if that is all you have, if you use large solder lugs on the ends and bolt them securely with #1/4-20 bolts or larger.

Connection to the anodes
You will probably need professional titanium anode baskets to increase the surface area substantially. At the very least, you need to have huge anodes to get the surface area. A rule of thumb is to keep the anode area close to the area of the item to be plated. So if your item is 500 sq in, you'll need an anode that is about 500 sq in or roughly 2 ft x 2 ft. You'll need to hard connect to the anode or anodes. No alligator clips or battery jumpers at 500 amps.

Plating Tank size
You'll be dissipating that 6,000 Watts of power into your plating tank. You'll have cooling problems with the tank. A wild guess is that much over 5-10 amps per gallon, you're going to start having serious trouble. This means you'll need a plating tank 50-100 gallons. That's getting beyond DIY plating unless you're very serious and have access to professional equipment and waste disposal methods.

I am not aware of any 500 amp switches that are likely to be affordable. Diodes that size are likewise very expensive.

Do a Google search and start collecting information. Understand each of the above subjects before moving forward.

Ken

[Fibergeek]

Allow me to address a couple of electrical problems with all this:

I thought for chrome plating the plating time was 3 minutes or so.

I also thought the actual voltage required was 3 volts or so. Ignore wiring drops for now. Just what is the actual voltage BTW? If it is 3V, then 1500W is required for the plating. You do realize you need to control the current if you actually expect to plate, and not just make a mess, right?

The 500A at 12V would only apply if you were limiting the current (500A) with something resistive (nichrome, light bulbs, etc.) or something else grossly inefficient. This will not be cheaper by a long shot at these current levels. For batteries, let's consider a high power DC/DC converter (12V in 3V out) now the numbers look like this:

If my 3V figure is right; from a 12V supply, 3V / 12V x 500A = 125A if the converter was 100% efficient, it's not. Since the converter would be around 70% efficient at this high current (500A) the actual battery current would be more like 180A.

For 120VAC, a (big) stepdown transformer driving full wave rectifier diodes (big ones) to produce 3VDC at 500A would be used, similar to an arc welder. These are nowhere as efficient as switchers, the 120VAC line will need to provide about 20 or 30A AC. 240VAC would be better.

An offline AC/DC converter could be used; the efficiency would be a little less than the DC/DC converter, but like the DC/DC, accurate current control could be provided, just like a lab power supply.

3000 Watt AC/DC units are available commercially, and could produce close to 1000A if you connections can handle it, they also provide excellent current control, but they're not cheap.

I agree that this is getting beyond DIY plating. But 10 car batteries?

[dadkar2]

The point is exactly that. This project is beyond simple batteries and rectifiers.

Ken

[dawghowseproductions]

Gosh i think im in over my head,ive listed my 250 amp rectifier ,2 twelve volt marine batteries ,i also have two mig welders,i really didnt realize this would be this difficult.Mabe ill have to go copy chrome,any other suggestionsHow about these new temperature settings,ive only used 110 degrees what do you think??Thanks Beau

[TamRon]

Heaters

Just want to thank you for all your Help Much appreciated .
Ron.

[chrisk]

taking inspiration from the 'woronko chamber' in the plating guide could it be possible to plate the wheel quadrant by quadrant?
Support the wheel by the inner rim which will not be plated on rollers and slowly rotate the wheel every hour or so?
One of those shaped baths tyre guys use to check tyres for leaks would be a great vessel for a bath in this case.
OK granted, this will probably take a day or two to triple plate but in just over a weeks worth of work you'll have a nice set of shiny rims (hopefully)

[gtabadboy]

Why not just plate half the wheel at a time. Im a newbie but I think this can be done. I would like to do this eventually. The line where it meets can be buffed out.

[customandsound]

So what you are sayind ken is for every square inch you need 1 amp per square inch?

I am going to be doing some mass searching here in the next few days ..

thanks
chuck