In wintertime four or five times we come together with 20 - 30 model T Friends.Next winter I like to demonstrate Nickel plating of small Model T Parts.
I don't know how that works! Is there one of you who can help me in the right direction for that demonstration??
Thank you in advance.
I an watching with interest Toon. I have lots of little bits for my current project. I have been looking at a Caswells kit but have no experience of same. Perhaps we will get some recommendations.
Allan from down under.
Caswell kits are very easy to use. Good documentation, and excellent phone support. Nickel plating is very easy to do. I have done, cad plating, flash copper, bright copper, and nickel, all with excellent results. I haven't purchased the chrome kit yet, but that is next. It is really great for all those small parts. They do offer brass plate, and gold plate, and others.
One thing to mention, if you use the kit, don't be alarmed if your part comes out with some black, fuzzy oxide on it, the oxide will polish off with a little work, leaving a nice, smooth layer of nickel. I used a Caswell kit to replate my windshield hinge thumbnuts and they came out very nice.
Like most things, the more time spent in preparation of the part (cleaning, polishing), the better the final results.
Actually, you should be alarmed if you see black on nickel. It indicates a zinc contamination and leads to porous plate. The plating will eventually bubble and flake off. The zinc in the plating bath can ruin everything you do after that too so the chemical batch is ruined. Never attempt to plate bare zinc or die-cast in nickel. It needs a non-acidic copper plate first.
Ok, thanks for the correction, Ken. My windshield nuts are solid brass, so I guess the zinc came from the brass. Does this mean that it is a bad idea to nickel plate brass? Is there a way to change the process when plating brass to prevent the oxide problem?
That shouldn't have happened on brass if it was clean and plated immediately at the correct temperature. I don't know what you're using for a process so I can't suggest a change. Zinc in the plating bath will give anything from grey streaking to black fuzz. It can come from previous parts or the hangers you use.
Some quick tips for electroless nickel:
1. Suspend parts in the tank away from the bottom and sides.
2. Don't insert the parts in the tank until the solution reaches at least 185°F.
3. Don't allow the solution to boil. Optimum temperature is 185-195°F. Boiling will cause a rough plate from iron impurities in the bath.
4. Brass parts, especially heavy/thick parts, require help starting the plating process. Use a clean steal rod submerged in the bath and touch the brass part. Hold the rod against the part until the reaction starts on the part. If the reaction doesn't start within one minute, remove the part, re-clean and check the temperature of the bath.
5. Clean your bath by taking advantage of tip #3. Bring the bath to a boil then let it cool. Filter the solution through coffee filters to remove solids. Then clean your tank.
6. When the bath begins to turn the slightest bit cloudy, it's spent. Make a new batch and start a new "nickel credit" ledger.
Thanks for the tips, Ken. I did my parts with the solution at room temperature, I'll try heating the solution next time.
I noticed that only the side of the part facing the electrode got the black fuzz, the side facing away from the electrode was shiny. Should I try for more separation between the part and electrode? They were about 2 inches apart when I got the fuzz.
Last January Chris Paulsen demonstrated nickel plating at the midwinter clinic in Hutchinson.
Note the finished samples on the table.
Some help from Jerry Hoffman.
Here's some nickel plating video:
You can find more info with a Google search, and I gather Caswell provides good phone support too.
Mark - The tips are for electroless nickel. I assumed most use that process since it's the easiest and gives a better plate. Electro-nickel is a different process altogether and the tips are different. The black is most likely burning and impurities in the bath. You should not have a "single" anode in the bath unless the part turns during the plating. Electro-plating is "line of sight" so you should use multiple anodes to cover the surface. The burning comes from the current being too high and leaching the zinc from the brass.
Thanks, Ken. I used the transformer that came with the Caswell kit (4.5 volts at 300 MA), but I'll search through my parts pile to see if I can find a transformer with a lower voltage output.
Voltage doesn't mean anything except to maintain the required current (Amps). The electro-nickel kits used to need 1 Amp per 16 square inches. Caswell has changed some of their chemistry over the last couple of years so you need to verify that. Using the 1 per 16 would be about 250MA for each knob at full coverage. With the anode on one side, you could exceed that by 200-400%. That's why it's better to use multiple anodes for full coverage.
You are correct that you can decrease current by moving the anode or part further from each other. Fixed transformers don't really give the best plate. Plating rectifiers allow for fixed voltage OR fixed current. In plating, fixed current is more important.
The end of the first paragraph should read "...use multiple anodes for full coverage and even plate". While the backside may have plated, it's probably very thin. It's more of a shadow plate.
How do you safely dispose of the used chemicals ?
I understood these were very toxic and bad for the environment
Back in the early 60's Popular Science published an article on making your own electroplating outfit. A school chum and I built one for a school science project. To our surprise it not only worked , it plated parts well. Copper and Nickel were easiest and safest to plate, we did plate some cad, but it was more toxic, if I remember right.
As I recall it used two rheostats, a voltmeter and an ammeter, and we powered it with a rectified model train transformer. Once set up it was easy to obtain near perfect results, as Ken mentions, maintaining a steady current provided the best deposition.
We bought our chemicals from an old laboratory supply store in Los Angeles our science teacher told us about.
Not toxic. Caswell explains how to dispose of safely. Check out their website. You will be surprised at how easy it is...
A follow-up on my experience with the Caswell kit (I nickel plated my original windshield pivot thumbnuts):
Ken mentioned that my experience with black oxide when plating on brass was a symptom of too high a voltage, leaching the zinc out of the brass. His assessment was spot-on. I checked the voltage output of the transformer in the kit and instead of the rated 4.5 volts, it was putting out more than 8 volts. I found another transformer that put out 4 volts and redid my parts, being sure to rotate them occasionally to ensure even plating coverage, they turned out great.
Thanks, Ken, for your help!