PhilAndrews

Replating reflectors

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I had a go at plating the front turn signal reflectors on my Chieftain.

 

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They were all rusty and someone had decided to paint them black.

 

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I think that came up pretty well, considering. Copper, then nickel plate.

 

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Lights up nice and evenly now. Quite a bit brighter, too.

 

Phil

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I've been asked for an explanation, so here goes.

 

What I wanted to do was nickel plate the steel of the reflectors for my front park and turn signals, because they had rusted quite badly and a previous owner had decided to paint them black.

 

It's possible to electroplate at home using things found at the grocery and hardware store.

However, I'll give the spiel now and get it out of the way- the chemicals you make with this process are at best toxic and worst, poison. Note this is also not a "in the kitchen" activity, more a "in the garage" one. Wear gloves (nitrile), safety glasses and if you get anything on your hands, scrub thoroughly with soap and water.

 

What you'll need:

Distilled white vinegar (5% minimum)- I bought a couple gallons at $0.85/gal.

Hydrogen peroxide

Copper pot-scrubbers (without the sponge in the middle)

A source of nickel (I bought 99% nickel welding rods at the hardware store)

A power supply (can also be done with a 6V lantern battery)

Wires and alligator clips

Glass dish big enough to fully submerge the item you're plating- plan to never use it for the kitchen ever again. I bought a Corning Ware dish at Walmart for $3.

 

Preperation:

You need to thoroughly clean what you're planning to plate. Start with the usual things, rubbing down with emery and wire brushing. The smoother the surface, the better the results. Heavily corroded items can be chemically cleaned with ascorbic acid in solution.

I chose to galvanically clean the surface also. 

Fill the dish with vinegar enough to cover the item and add a pinch of salt to boost the conductivity. Don't go overboard with the salt.

Connect the + lead to the item to be plated and the - to a piece of wire immersed in the vinegar. The wire should fizz. You'll notice the item to be plated will begin to turn a dull gray (if steel).  This surface is clean enough to plate metal onto.

 

Copper plating:

Nickel doesn't stick well to some mixed of steel, so plating first with copper provides a galvanically more compatible surface.

You need to make copper (II) acetate by dissolving a copper scrubbing pad in 50/50 peroxide and vinegar until the solution turns pale blue. Left too long it'll go a deep Royal Blue and that'll be too strong (it passes too much current and the plating will be poor).

Twist a scrubbing pad up into a teardrop shape. The bottom goes into the solution and the top sticks up to connect the wire to. Make sure the wire doesn't contact the electrolyte solution else it'll be dragged in and pollute the chemicals.

Connect the - terminal to the object to be plated, the + to the scrubbing pad. Keeping the object to be plated as far away from the scrubbing pad as possible (at least an inch) and constantly move and rotate it. The solution will precipitate chunky flakes into the electrolyte and they settle, forming spots that don't plate properly.

If you have too much current passing, you'll get black oily deposits which will just wipe off. Slightly too fast and you'll get burgundy flaky layers. Just right and you'll get salmon pink. It'll work anywhere down to about 0.6 volts- you can use a D cell battery if the lantern battery plates too fast.

 

Nickel plate:

The electrolyte for this is nickel acetate, but the molar strength of vinegar isn't enough to dissolve the nickel by itself. 

Fill the dish with just vinegar and add a pinch of salt. Make 2 nickel electrodes and connect one to + and one to - and connect to the battery. After a couple hours the solution should turn pale green.

Take your clean copper plated item, hook it to the - and leave one nickel electrode connected to the +, and immerse the item, rotating slowly. 

 

Once plated, wash with water then polish with a gentle polish (brasso or similar). 

 

Store the copper electrolyte in a container marked COPPER ACETATE - POISON, and the nickel electrolyte in another marked NICKEL ACETATE - TOXIC.

 

Alternative power- I used an old PC ATX power supply. It has a range of voltages. 3.3, 5 and 12. They're cheap (this one came from a junk computer, 330 watts). I have some resistance bulbs to limit the current also as it is more capable than really required.

 

Phil

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That is an interesting way of doing things.  You can also get all kinds of plating supplies and equipment at Caswell (look up on the net.).  I replate a lot of small items as it is less expensive and more fun than sending out to get plated.

Edited by nickelroadster
addition (see edit history)
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Yes, they do have some excellent kits.

 

I had wanted to see if I could do it myself, the last time was with copper (II) sulphate in high school, which is particularly nasty stuff. Not that copper acetate isn't, but it's slightly less bad to work with, and easy to create.

 

A self-challenge, if you will (rather like the whole vehicle).

 

Phil

Edited by PhilAndrews (see edit history)

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PhilAndrews,

 

 I'm sure that your reflectors came out nice and will last a long time.

 But, I am lazy and I took my rusty reflectors and brushed them with silver POR15. It is the best silver paint that I have ever seen!

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POR-15 is good stuff! 

 

I looked at it this way - the reflectors were in bad shape. I can get replacements but I might as well try a few home remedies first. My first port of call was paint. I used aerosol Rust-Oleum silver because it's actually quite shiny, and it was. It really improved the reflector but looking at the lamp straight on looked quite gray. Despite that the light output wasn't bad. What I didn't like was the backplate being visible through the lens, a completely different color.

 

I figured what the hey, let's investigate making them both kinda shiny. The rest of the front of the car is. So, I plated them. Both to provide a shiny surface and provide protection to slow the deterioration of what is a piece of steel in a very exposed location on the car.

 

I did step back and think about it though- there were signs that the entire assembly lamp-side was originally just painted white!

 

Phil

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These also have my Safety Turn Signals so I wanted them to be as effective as possible, low down and the "wrong color" by today's expectations.

 

I've seen a lot of older Lucas lights just painted either white or the same pale blue the inside of gauges are painted also.

 

Phil

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Hi Phil. What would it take to electroplate silver ? Could it also be a two step process, or would it require 3 ? I imagine clearcoat over silver would be durable, and maintain the highest reflectivity over a very long period of time. There is another technique to precipitate a silvered surface. I don't know if it can be done on a metallic surface, as I only know of its application to a glass substrate. It is a chemical deposition requiring care in at least one byproduct. That is fulminate of mercury, a percussion explosive. Amateur astronomer telescope builders were quite familiar with this decades ago. Also used  by commercial glass companies to coat the mirrors everyone uses. Thank you for your detailed explanation. I myself am too feeble and absent minded to try it, (not quite at the point I would take a beaker of poison for my diet Coke, but I do some AWFULLY stupid things these days), but I'm sure there are sound minded folk here who can't miss using your instructions.   -   half spent, and getting shorter every day,   -   C Carl 

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C Carl, I'm not sure. Certainly more than acetic acid. I do however know how nasty mercury fulminate is, and personally would leave silvering to the professionals. That's just me...

 

Phil

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