How to Remove Varnish from Brass

A. Hi,

I've been looking for answers to the same question. I was particularly looking for a non-toxic way to remove the lacquer. I found the following link in a google search just now; haven't tried this yet, but wanted to pass it on:
www.heall.com/body/healthupdates/environment/nontoxiccleaning.html

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Ed. note Feb. 2014: Sorry, that site is now defunct and the link is broken.
Readers: if offering a link, please try to at least summarize what it says or give us the title of the article because almost all links fail in short order, and then people are left wasting their time bouncing around the internet from broken link to broken link. We want to post answers here, not broken links :-)

A. I removed the varnish from a brass door knob using hot vinegar. Half the varnish had warn off the knob after fifty years, but half remained in a yellowed state. I placed the door knob in a glass custard cup and poured in white vinegar up to the brim. I removed the door knob from the custard cup and put the vinegar in its cup into the microwave. After just bringing the vinegar to a boil, I returned the knob to the hot vinegar bath and let it stand for 15 min. The varnish slid free like loose cellophane. The entire knob was then polished with brash polish and looks great. For items that don't fit in a microwave, it may be possible to drip hot vinegar over the surface. White vinegar is cheap and non-toxic, but use with plenty of room ventilation.

I learned this technique in Army ROTC in college, where we were issued brass U.S. Army insignia for the uniform. These came coated with the clear varnish. Naturally, the varnish had to be removed so the brass could be polished thereafter.

Re. Brass Varnish Removal --
Method described by Barry Johnson,- Blue Bell, Pennsylvania works like a charm.
Hot vinegar removes varnish/lacquer easily and cleans brass at the same time.
Thanks

Check out Barry Johnson's solution. Brilliant.

Barry Johnson's solution worked great!

Barry Johnson's solution is amazing. I have 2 brass beds that are 140 years old; I bought them 35 years ago; they were lacquered. The last few years they looked awful, but no time to work on them. Read the internet, and thought that hot vinegar would not work -- it works. Easily and no chemicals. Put the vinegar on my grill and took the beds outside. They are great. I am not going to lacquer them. Can brass polish them whenever they need it. Everyone needs to try a spot to see how easy and clean it is. Thank you Barry Johnson.

A. To remove old paint from brass fittings, just coat them with paint-stripper, rub, rinse clean and buff up with soft steel-wool with or without a few drops of ammonia!

A. Hi. Methylene chloride based strippers like Aircraft stripper [linked by editor to product info at Amazon] are harmless to metal but very aggressive toward all paints and varnishes ... and people. Use only with chemical rubber gloves [linked by editor to product info at Amazon] and goggles [linked by editor to product info at Amazon] (as a minimum) and with excellent ventilation (preferably outside and standing upwind). Some strippers are caustic based and those can harm brass.

Ideally, the brass was protected with brass lacquer rather than heavy varnish. And brass lacquer is designed to be easily removable with lacquer thinner [linked by editor to product info at Amazon] or acetone [linked by editor to product info at Rockler].

Regards,

A. Hello William,
There is a product called Citristrip sold at Home Depot. It's about $20.00 per gallon, but a lot more friendly to work with than using Acetone or other thinners. You can brush it on and leave it for some time and the varnish will come off easily. I've used it on brass hardware and door kick plates and works well.

Hi Cindy. Be careful; caustic soda is not sulfuric acid, in fact it's just about the farthest thing from it. Caustic soda is the most common drain cleaner, but sulfuric acid is also sometimes used for that purpose, and they are completely incompatible, with caustic soda being just about as alkaline and can be, and sulfuric acid about as acidic as can be. They will react rather violently with each other if mixed, perhaps boiling and splattering everywhere.

Regards,

A. Hi Dana. The most powerful and universal stripper for organic coatings like clearcoats -- and which should not harm any metals -- is aircraft stripper (methylene chloride). But this is truly terrible stuff for people: you need to work outside with good ventilation, and wear industrial chemical rubber gloves [linked by editor to product info at Amazon] (not dishwashing or food service gloves) and goggles [linked by editor to product info at Amazon] as a minimum. Rubber apron, boots, and sleeves would not be inappropriate, although maybe not needed for trinket size work.

Regards,