Chemical blacking for P/B

I must assume you have not yet downloaded and installed Google onto your computer. As no less an authority than George W Bush, the President of the Untied (sic) States of America has informed us, Google is available on one of the Interwebs. Having logged onto the Interweb of your choice it should be possible to find Google by searching on Lycos, Altavista or any other search engine. If you are unable to find Google then try another Interweb. Once located you can download and install Google and then search for topics of interest on it.

Such a search on the topic above might well find something similar to this

For further information, or just humorous linguistic gaffes, try contacting Mr George W Bush at

snipped-for-privacy@whitehouse.gov

-- Dave Baker - Puma Race Engines

I think that reply comes under the heading of "beating around the Bush"...

Regards, Tony

Blowing the dust off my old copy of "The Practical Metalworker" here's what's written on the subject (for brass) :- "Blackening Brass. There is considerable demand for a satisfactory chemical method of blackening brass, and since the most generally satisfactory method is probably that which utilises copper carbonate dissolved in ammonia solution, the Eastman Company has conducted a number of experiments on the best conditions for obtaining a good black deposit. One of the experimenters states that it was found that in the preparation of the solution the most important points are the concentration of the ammonia employed and the preparation of the copper carbonate. The copper carbonate is precipitated by adding a hot filtered solution of sodium carbonate to a hot filtered solution of copper sulphate, and is then washed very thoroughly by decantation until test shows it to be free from copper and sulphates. This thorough washing is very essential. The copper carbonate can then be filtered by using an aluminium filter dish and kept in the form of paste, though it is sometimes more convenient to dry by heat and use the powder. Paper must not be used for filtering because small threads may dissolve in the ammoniacal copper solution and affect the result. The brass to be blackened should be agitated in the solution at a temperature near 100 degrees F. After blackening, it should be rinsed off and either dried or baked. The most satisfactory solution will be found to be as follows :

10 per cent. ammonia .. 25 parts Dry copper carbonate .. 5 parts Water to make .. .. 100 parts The important part of this formula is the exact amount of ammonia used, and this will vary slightly with the nature of the brass; a considerable increase or decrease of the ammonia will prevent a good surface being obtained. Some of the copper carbonate will remain in suspension since the ammonia will be insufficient to dissolve it all; the undissolved carbonate, however, will do no harm. The time of treatment in the bath will be from fifteen to thirty minutes to get a satisfactory black deposit."

Let us know if you try it !!!!

Not an answer to your specific question about chemical agents, but I've used with success on coil springs a product from that excellent company Frost.

It is sort of "plastic dip" for tool handles etc. They do it various colours (inc black). Part of the advertising blurb states "Retaining its elasticity even under the harshest conditions".

I've been quite impressed with its longevity.