Triple Chrome process?

[AdminGuy]

What specifically is the triple chrome process?
Is it nickel, copper, chrome? or copper, nickel, chrome?

Do you have to copper under CAD to do it properly? Or is that just a prelim fill?

[AFJ]

Traditionally, the bare metal is polished, then copper plated and polished to remove imperfections (could be done several times on a restoration to get the surface right), then nickel plated, polished again and then the chrome "flashed " on in a few minutes treatment.

But on 1929 and earlier British bikes stop at the nickel plate stage - it was not until 1930 that most British bikes used chromium plated components.

AFJ

[Pete Gagan]

Chrome started in the USA at the same time.
Pete

[inrustwetrust]

When it comes to the copper coat, this is often the weak point in the show chrome, and nickle too. It is much like primer, if put on too heavy, it will come off under stress, such as tightening bolts. When cad plating spokes, I would be careful of using copper. I've never heard of copper under cad. Cad is a sacrificial layer that is actually self mending to a degree and electrolitically prevents corrosion of the base metal. A while back I decided that it would be a good idea to cad plate stainless spokes. They were cheaper than steel and would never rust. Cad plating the stainless created a situation called hydrogen embrittlement. I brought both wheels up to low torque and went home for the night. The next morning when I returned and spun the wheel. It jingled. I looked closely and discovered that about one quarter of the spokes had broken at the spool end. Now, I always use steel spokes and have the plater normalize them to prevent embrittlement. With old parts that are under stress, normalizing is just good practice, and does not affect heat treating as is is low temperature.

[AdminGuy]

Good info. Thanks.

My "highly evolved" (I look at them with wonder and amazement) scout friction dappening plates were base copper. As were hollow axel nuts. So this is why I'm kinda thinkin that they may have base coppered the stuff before Cadmium plateing it. A little fill. Not that I would replicate this process. I'm just curious as it's giving me some clues as to what was cad.

I hear triple chrome holds up better for exhaust headers. Discoloration. I guess because of the thicker plate? Or is it the material?

[AFJ]

Many years ago I was told that if chrome plating had a blue cast or tint to it it was of the correct thickness, but that if it had a yellowish colour it was likely too thick.
Once had a set of pipes plated and on heating and cooling a few times the chrome came off in sheets, leaving the underlying nickel plate.

AFJ

[AdminGuy]

So I guess it was too thick? Is that right? Or maybe it was the prep under it?

Has anyone ever fooled around with inner ceramic pipe coating spray of some sort? Did it work?