DISCLAIMER:
The following is full of astronomically bad ideas. Death, dismemberment, multilation, castration, and all other ensuing results aren't my bloody responsibility. Follow along at your own risk!
Now that we've got that over with, I'm currently setting up an electroplating bath in my basement. While I could always go a rather nice kit from Caswell, the massive cost of buying an aluminum and nickel bath combined with the risk of destroying $80 worth of materials with a bit of zinc has led me to try my hand at a DIY setup. Since I'm going to be plating "virgin" materials as opposed to those which have already been worked or used, I won't have to worry quite so much about regulating for impurities, and any finish irregularities can be rectified with a bit of polish and a lot of buffing.
Despite the recommendations of a lot of stodgy metal finishing professionals, I started reading through old jewelry and hobbyist guides. After a while, I found this rather excellent article in an old copy of Popular Science:
http://books.google.com/books?id=VCEDAAAAMBAJ&pg=PA124&lpg=PA124&dq=%22nickel+sulfate%22+%2B+plating+lab&source=bl&ots=KXFmxrdvCA&sig=X9iz-WjQU4j3PYvlwvu7wa9E_J0&hl=en&ei=-VkdS8n0G8PL8QbF-rDnAw&sa=X&oi=book_result&ct=result&resnum=7&ved=0CCQQ6AEwBjgo#v=onepage&q=%22nickel%20sulfate%22%20%2B%20plating%20lab&f=falseand figured I'd give it a go.
Here's my plan:
1.Power supply: Car battery charger with rheostat and ammeter for large items, and a current-regulated PSU for small ones. I might build a 5-10A current regulated PSU if I can get the baths to work, but what the heck.
2.Strike bath: This is an initial plating which will hopefully isolate the other baths from any impurities in metals to be plated. Because I hope to plate steel (to which an ordinary acid copper plating solution won't stick), I'm going to try using a very simple plating solution made of nickel sulfate and boric acid (wasp killer.) If I can't make this work, I'll buy some premixed "stick-to-everything" copper plating bath from Rio Grande (
http://www.riogrande.com/MemberArea/ProductPage.aspx?assetname=335163&page=GRID&free_text|1260330466733=copper+plating), though at $30/quart, it's kinda expensive.
Instead of using a big bath full of expensive and easily ruined chemicals, I'm hoping to use a brush plating solution instead. Apparently, a crude plating brush can be formed by sticking a stainless steel or graphite insert in a Scotchbrite pad and using it like a paintbrush. While this is kind of a pain in the ass, it does have the major benefit of only contaminating the solution I use on that particular piece.
3. Copper bath: This is the most important bath - not only can I get a shiny copper finish, a thick layer of copper can cover up all sorts of nicks, scratches, and whatnot. Also, copper is relatively cheap and very easy to get. A thick layer of copper will be plated on just about anything I do, making this bath important.
While I'm told that a simple solution of sulphuric acid (sold as battery acid or drain cleaner at most hardware stores) and copper sulfate (sold as root killer at most hardware stores) works relatively well over all copper- or nickel-based alloys, I spent a bit of money and bought a refill of the proprietary chemical additives from Caswell Plating's copper plating kit. (
http://www.caswellplating.com/kits/copper.htm) Assuming that the "copper crystals" they sell are just copper sulfate (there's not much else they could be), I should be able to reproduce their copper plating bath at a fraction of the price.
4. Nickel bath
This is where things get tricky. While copper plating can be done with stuff from the hardware store, nickel requires a bit more work. Unlike copper sulfate (which was used medically until very recently,) most salts of nickel are very toxic - even if they don't kill you now, they're also quite carcinogenic (though, let's be fair: These days, what isn't?). As a result, I'm going to be very, very careful, and probably mix this stuff up under a fume hood.
While nickel plating is generally a very complicated affair, it can be done relatively simply. A simple solution of nickel sulfate (cheap on eBay!) and boric acid (wasp killer) will supposedly plate to most metals, but there's a catch - the nickel in the solution is quickly depleted and cannot be replenished. However, the addition of nickel chloride transforms this solution into the Watts' Bath, capable of taking the electroplated nickel from a solid nickel electrode.
The problem is that while nickel sulfate can be bought relatively easily on eBay, nickel chloride is much harder to buy, and much more expensive at most vendors. However, I've managed to find an educational distributor that sells both nickel chloride and the nickel plating anodes relatively cheaply:
http://cynmar.com/item_detail.aspx?ItemCode=CHN84454. It's less than 1/3 the price of everywhere else, and they'll sell to anyone!
5. Conductive paint
Conductive paint is not cheap stuff, but it is immensely useful: Paint it over anything - any sort of metal, rock, organic material, Howard Jones, whatever - and you can electroplate to it. Not only does this allow for the plating of things like leaves, it can also be used in conjunction with Bondo or other fillers to cover over holes and marks in a finished project. Just cover up the marks with the filler, sand smooth, apply with paint, and give a good coat of copper - no one will ever be able to see it!
More details to follow....