Q. I have an antique wall-mounted glass/soap holder. It has brass underneath. Is there any way I can strip the chrome off the brass at home?
A. Roberta, if the coating is true chromium it will be dificult to remove without affecting the brass base metal or any other coating that may lie underneith. Difficult but not impossible.
If this was a typical decorative finish from years past, it may be a thin layer of chromium directly on the brass, it may be chrome over top a thicker layer of nickel. There may or may not be a thin layer of copper under that. There are specially formulated "coating strippers" for these applications, but they are not available to the "do it yourselfer". If the item is an important aire-loom, you will be better off taking it to a local plating shop that specializes in antiques, for an opinion...
That said, if you're not willing to take it somewhere to be done, there is a possibility that you might be able to strip the outer coating of chrome from the item at home.
If in fact it is "chromium" and not something else, check with your local hardware store for an over the counter product called "muriatic acid". This is a dilute form of hydrochloric acid, and available to anyone for cleaning sandstone, cement or brick, (i.e. fireplaces or sidewalks). Muriatic acid should remove the layer of chromium (only hexavalent) from the surface in a few minutes, but it will certainly damage the brass if you leave it submersed for more than a few minutes at a time.
For the acid to do its' job, the surface of the item would have to be thoroughly cleaned to remove dirt, grime, grease, oils, paint, varnishes etc. Clean deep crevaces and all nooks and crannies, seams and holes thoroughly with a good solvent and a brass or stainless wire bristle brush. The chromium surface must be exposed so the acid can remove it quickly. Chromium will fizz slightly as the acid begins to attack. It may take several attempts to remove the chromium shell to expose what is underneathe. This acid will not remove nickel. If you attempt this, use this product in a well ventilated area away from everything. Acid fumes can rust metal and etch objects it comes into contact with. DO NOT LEAVE IT UNATTENDED!!
If your plan is to change the appearance of the brass from chrome plated back to brass, stripping only the top layer of chromium may not give you what you want especially if nickel and or copper are present underneathe. Good luck, and email again if you have more questions... sending a photo of the item may also shed more light. take care
Best of luck.