Galvanic coating of the Dunlop "C" cylinders

[Desmo]

Hello,

Were the cast iron Dunlop brake cylinders originally zinc or cadmium plated? During the forthcoming overhaul, I would like to restore them to their original appearance.
Thank you for your hints.

Best regards
John

[Heuer]

Cadmium

[cactusman]

Unless you know someone in the aircraft business then cadmium plating is no longer possible (in the UK)...

[Desmo]

... Unfortunately.

Thank you both for your information.

Best regards
John

[Heuer]

Quite a few places in the US, every street corner in India!

Very difficult in Europe although if you look east there will be places. Personally, unless it is on OBL, I would say it is not worth the trouble or expense.

CMC did an early OTS and cad plated everything, including all the handbrake parts you cannot see. Can't remember the cost but it was high.

[cactusman]

You could get them zinc plated...it's the std replacement for cadmium where cad plating is no longer permitted (or is prohibitively expensive)..

[Series1 Stu]

Zinc plating is what you would get if you sent them away for reconditioning by a reputable supplier. If you're going to strip them yourself and send them for plating make sure your supplier is fully conversant with plating cast iron parts because of the particular pre-treatments required.

Regards

[Desmo]

Hello Julian, hello Stuart,

I have agreed a silver zinc plating with the workshop. The workshop is PastParts Ltd. I got 4 original used cast iron 1/8 Dunlop brake cylinders for the front axle as a possible replacement some time ago. Now that I have decided to overhaul the units belonges to the car, I will offer them for sale. It is interesting that these replacement cylinders were not cadmium-plated but merely blackened or painted black.

John

[mgcjag]

If you go for zinc plating ensure that it has a passivant coat..if not the zinc will go gray and powdery...Steve

[cactusman]

Yes...wise word Steve...

[Series1 Stu]

It's likely to be a clear passivate coating these days so it will be grey/silver in appearance.

Regards