Jewelry and Interior Hardware Applications
There is really no “right” way to do this. You could apply a lacquer to it, but lacquer could be a problem because if it gets scratched or chipped, it may peel and you would have to strip it and re-do it. Waxing it is also an option, but to look good, wax has to be maintained and re-applied. We recommend doing nothing to it and letting it continue to age and wear naturally.
The Jax Pewter Black will definitely work on both the brass and the pewter and it will make them both the same color. For your information, the Jax Black will definitely work on the brass and MAY work on the pewter. The Jax Black will make the brass “blacker” than the Jax Pewter Black. There is no substitute for actually trying the chemicals on the specific metals you are trying to blacken.
Jax Brown-Black is the product we would recommend, but you may have a major stumbling block in the removal of the lacquer on the new doorknobs. Chances are the clear lacquer over the brass is epoxy based, baked on or electrostatically applied (or a combination thereof). The Jax Products will only work on the metal itself so the clear-coat will have to be removed – we have nothing that will help you remove this type of lacquer. IF you are able to remove the lacquer, Jax can help with the rest, but you will have to experiment to achieve a color-match, and Brown-Black is the most versatile option here.
The Jax Silver Blackener will NOT hurt your diamonds. Everyone blackens silver with the diamonds in place.
The question really is how much tarnish is involved. The Jax Brass Copper and Gold Cleaner is an extremely mild solution that will remove light tarnish and oxidation from fine jewelry, gold, silver and well-plated items. The Jax Brass, Copper, Gold and Marble Cleaner is more aggressive and also contains ammonia. These first 2 products are classified as “non-hazardous.” The Jax Instant Silver Cleaner is even more aggressive and will remove all oxidation (it is not safe for plated items) – it may also leave the metal a little “dull” which may require some additional polishing. This product would be classified as “hazardous.”