Wednesday, 7 March 2012


I am in possession of a secret formula of such value that I hesitate to mention it in a public place such as this. The formula is handwritten and ancient and has been passed down through the generations. The origins of the author are lost in time although I believe that he was a chemist who lived far north of here. The formula would have been lost were it not for the sharp eyes of a friend of a friend of mine as he sorted through the dead chemist's notes.

The formula gives the keeper the ability to turn base metals into nickel plated base metals.

I would love to be able to say that I've been using this secret recipe for years to do all my nickel plating, but the truth is I was only given it a few months ago and I haven't tried it yet. I've been using a commercially available kit for over a decade with excellent results.

This past week I've had an interesting discussion with Tim, an English friend of mine. Tim and I share the view that modern, bright shiny nickel is not an appropriate finish on antique cycles. The nickel plate of old was more mellow yellow than the hard bright finishes available today. This is what originally led me to try my own nickel plating. Old nickel is often quite dull, more of a satin finish. I note with interest that Frosts now sell a dull nickel kit on the above link. If you live in England it may be worth giving this a try. Some of the dullness and colour of old nickel is partly due to the years of oxidisation and environmental pollution. I've experimented over the years with chemically accelerated ageing of fresh nickel. I own a copy of  "The Colouring, Bronzing and Patination of Metals" by Richard Hughes. This huge volume was my own starting point in this adventure. My most recent experiments have involved using the natural geothermal hot springs here in NZ. Some of them will turn any nickel coins in your pockets black. Geothermal hot springs are marked on the topographical maps with a red cross, further experiments will follow...

As an aside, it is an easy matter to 'turn' chrome plate into nickel plate. Chrome plating is always applied on top of nickel plate (which may or may not, in turn, be on top of copper plate). The chrome can be stripped from the nickel with no harm to the nickel by dissolving the chrome in hydrochloric acid (also known as spirit of salts or muriatic acid). I usually dilute my acid (add acid to water, not the other way around) and leave the components for about 30 minutes, then dunk into a strong solution of baking soda (an alkali) to neutralise the acid and prevent rusting of exposed threads etc. Rinse with fresh water and you are done. by the way, HCl is truly horrible stuff, do this at your own risk and use lots of PPE.

So this week I've been polishing and plating all the bits made so far.

Polished, ready for degreasing.

Polishing on a high speed rotary buffer is hot, dirty and dangerous. The potential to loose fingers is high as is the potential to have your exquisitely made components flung randomly around the workshop at high speed. You need to be careful, very careful. And alone with no distractions.

Cleanliness and preparation is everything when plating, the actual process is just chemistry.

Note the dull finish, I've spent ages trying to perfect this.

Plating adds a very thin layer to the base metal, usually not enough to effect clearance except where tight clearances are already designed in. Threads usually need a quick clean out after plating.

Soft soldering the flanges onto both hubs, 
note the three threaded wires installed to ensure 
that the flanges are timed correctly relative to each other. 

The temperatures used for soldering with lead are much lower than will effect the temper of the hard hub centres so this is safe to do.

The completed hubs.

The rear hub is familiar as being similar to a modern front hub. The front fork legs need to be sprung apart to install the front wheel when it is built, being 4130 this is possible without fear of bending or breaking. Assembly is then as described before

This is the first time that the front hub bearings have been assembled 
with the flanges in place and you can now just see the labyrinth seal 
formed by the recess in the flange and the inner bearing race.

In this photo I've installed a pair of threaded wires 
of the same length as the spokes to check that 
I have the spoke angle in the hubs correctly calculated.

Next week, I'll start work on the hollow rims.

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