What kind of black plating on Gpz fastners?

These are the nuts that hold the meters in the housing on a 1975 Kawasaki S1A 250. I use a 6 volt charger hooked to this variac and it works great. I also bead blast my anodes after each use. I strip my hardware with acid and if need be buff with 0000 steel wool before plating. I keep my solution temp. between 100 and 110 degrees. I start the pieces out with very low voltage for a few minutes and then turn it up to where it should be. There is no reason to not get great results with the Caswell kit. The intake clamp is the same black chromate, just not left in as long. This is exactly what the original clamps looked like.

You get that green by using the black chromate? I'm amazed. I've found that a fast dip in the black turns the part dirty yellow, not green.

Here are some parts I've done. Realize, I don't care if the parts don't shine like chrome. I just want them reasonably shinny and well protected. And with the least work I can get away with. Oh, and I used to use a battery to drive the system but switched over to a power supply more recently. The results are similar though.

Nessism - Those parts look GREAT!!!!!!!! Ed

It looks to me like your plating kit is working very well, nice results. I don't know why your chromate is dull, I wish I did so I could tell you.

Here is one more photo showing some GPz foot control parts that were installed on my 750E. The photo is not the best but it shows the slightly hazy bluish appearance that the Caswell's blue chromate imparts. The chromate increases durability of the plating so it's worth it to me but dulling down the finish wouldn't be my first choice.

In commercial zinc plating, the glossy black finish is "hot" black chromate conversion. This is done in a heated chromate solution tank. "Cold" black Chromate is done at room temperature and gives the dull flat finish.
I am also a big Caswell fan and have been using the system for about 10 years. I experimented with heating the Caswell black Chromate solution. I stole some of my wife's tupperware and heated the solution in the Microwave when she was off spending money. It did improve the gloss slightly. The most noticeable improvement was using a sealer as suggested by Caswell. Do the Black chromate conversion dip and allow the parts to air dry as normal. Then repeat with a dip in WD-40, allowing them to air dry again. I thought the parts would be oily to the touch and the gloss would wipe off, but that isn't the case. They come out very close to a "hot" glossy finish. I also experimented with a hot air drying. This didn't help and tends to give a cloudy finish. Temperature and sealing didn't make any difference I could see with the clear (blue) chromate.

So I ended up buying a plating kit from Gateros Plating in the UK, www.gaterosplating.co.uk/ pretty pricy at 55 £ considering what you are actually buying. Everything except the passivation chromates can easily be obtained locally, but without the passivation chemicals I am getting nowhere. So I bought their 5L kit and supersized it with olive drab passivation with extra darkener.
With a staggering 40 £ shipping to Sweden it came out quite expensive.
Anyhow today was the day to do a first test run.
• Wire brushed a couple of M6 bolts, nuts and washers
• Soaked them in naphtha based degreaser, brushed with a nylon brush, rinsed in scolding hot water.
• Soaked them in warm sodium carbonate as an alkaline degreaser, brushed with a nylon brush, rinsed in scolding hot water.
• Soaked them in the Heavy Duty Alkaline Cleaner that came with the kit, really aggressive stuff that started the metal to fizzle, quick dip in clean water.
• 30 second dip in the Acid pickle that came with the kit (Sodium hydrogen sulpahte) pretty strong acid that instantly makes the hydrogen start fizzing from the metal, quick dip in clean water.
• The into the Zinc electrolyte running on a reduced bike battery, within a minute all metal surfaces were covered in Zinc, but I left them for 10-15 minutes , then quick dip in clean water.
• Finally a quick dip in the clear passivates and left to dry.
It comes out really nice, all covered and shiny as new. (actually shiner than new)


Sorry for the shitty photo, but I think you can notice the difference.

But off course it all comes down to the preparations. I need to be more thorough when cleaning the fasteners as I could see some imperfections, so I sealed up all the chemicals in plastic cans and spent the rest of the day brushing fasteners and getting ready for the next time I will have a chance to give it a go and then I will see how the darkened olive drab will turn out, GPz black or not.

Gun blue, what a great idea! A particular brand you are partial too Barney?