For anyone who really is looking to have more control over the complete look of a piece, here is an excellent article by Architectural Classics entitled How to Age Brass – Ultimate Guide. Definitely worth a look if you are interested in the specific process. (UPDATE 2022: that site is offline – we have archived the article below instead).
A few good books on amazon on this subject as well:
Brass is one of the more common materials for your old home’s furnishings and hardware to be made of. Back in the day (when your grand dad was but a twinkle in his pop’s eye), it was the cheapest, most readily available and most suitable metal for creating these pieces. Coincidentally, it also looks lovely when it is aged! Shiny new brass can look a little bit like it came from a thrift store, or was just the cheap option when you went to the furniture store to replace your door handles, your knockers or your latches. The other thing about getting brass objects which are new and shiny is that you will often have older pieces in your home also, perhaps because they’ve been in your own home for ten or twenty years (or … admit it… maybe even thirty ☺). Or you may have bought them with a lovely aged patina on them already, from an auction or a dealer who didn’t feel the need to make his antique pieces look like you were the one who stepped back into the 1800s, when they were all new, rather than the piece coming into the twenty-first century!
So, those of you that love your old home, your old furnishings, and your old hardware, and want them to look old and mellow, may want to age your brass so that it fits in with the rest of your house, or for several other reasons. Here are some of the circumstances in which you may wish to age your brass times, taken from real-life dilemmas:
- Either you or somebody else has cleaned your brass door knobs, fittings, chandelier structure, or ornaments, with the best of intentions. You’re happy that it’s clean and sanitary, for sure, but you weren’t expecting it to look like it was born yesterday! Your brass is now glowing, and mismatched with everything else in the house. You want to turn back the clock just far enough to make it old again – not turn it back to when it was made!
- You may have older brass ornaments, for example lamps or chandeliers, that have many components. Time being what it is, some of the parts have been lost, and it is possible to complete the set with parts that you buy, but all of these parts are new, and will make the piece look like a dog’s breakfast of bright and dull parts. You want to age the brass before you put the piece together, to make it look consistent.
- You have bought a reproduction of something which is beautiful, but would have been out of your price range to buy if it was the genuine antique. Obviously it isn’t old … but the rest of your furniture is, and you want it to match. Newer pieces are often varnished to help the shininess last longer, also, and you don’t want it to take thirty years to get it looking the same way as the rest of your stuff does! How do you get the varnish off, and mellow out that ‘new’ look?
Make sure it is brass!
The first step in getting your new brass back to old is making sure that your item is actually brass! The aging methods described in this article mostly depends on reactions between the specific molecules that brass is composed of, and the agent used to develop the effect. Bronze or copper materials will react totally differently with many of these agents, and when you are handling chemicals, unexpected introductions into the mix can have dangerous results. Ensuring that what you think is brass, actually is, is one of your basic safety precautions. Besides, it stops you wasting your time concocting lotions and potions that just won’t work! Take your item to an antique store or dealer, and have someone used to handling these items tell you what it is made of. You should also be able to pick up some handy hints on how to spot differences for next time.
The next step, another one which is critical for safety, is to remove the varnish. As mentioned, any extra chemicals thrown into the mix when you are mixing up these brews can have very unexpected results. Varnish is a common one which may cause problems – it is both reactive and flammable. Remove varnish first by using acetone (nail polish remover), painted on with a brush, and then by boiling smaller items in water. For larger items, wipe the acetone off with hot water and leave it to dry before starting your aging process.
The gentlest methods with the most commonly available materials are usually the best ones to try first.
Salt and vinegar
Salt and vinegar is a great one … unfortunately you need them separately, so no excuse to buy the chips! You can use a small paintbrush to brush vinegar over the entire surface of the item. This oxidizes the brass, which is actually what happens to the metal naturally over time, the process of oxidization. Painting saltwater will have the same effect, only take a bit more time and patience on your part.
Brass can also be oxidized using heat or flame – if you have ever heated up a needle to sterilize it before popping a blister or removing a splinter, you will have noticed that the metal gets a gorgeous rainbow effect to it, which doesn’t wash off. This is what happens when steel oxidizes; brass will apparently not develop rainbow colours, but simply gets the old and mellow look much faster. An important safety note, though – make sure your brass is unlacquered – lacquer is flammable and could do you a lot of damage if it catches on fire.
Of course, you can use modern methods to make antique-looking brass, also. God bless science! There are plenty of products on the market which have been created, tested and proven to make brass and various other metals look older. The products made by Liberon Waxes are readily available – they have products for aging iron, brass copper and bronze, and you can choose from various colours for your finish also. They are easily applied by diluting them and then wiping them on with an absorbent cloth, however, note that they actually leave a colour deposit on the surface, as opposed to changing the composition of surface metal, and this colour is easily rubbed off through normal use.
Another method using specially manufactured products is called ‘acid dripping’ … sounds dangerous, I know, but just follow the instructions! You will find some mixtures called antiquing solutions with only a little bit of research. These are a dilute mixture of copper sulphate, acids, and other ingredients for colour consistency and contamination resistance. Follow the two mandatory safety steps above – making sure your item is brass, and de-lacquering it. Your solution will have its own instructions, which should be read in conjunction with this guide – if any instructions contradict each other, go with the bottle, as the manufacturers know what has gone into their specific product.
Prepare a dilute solution of one part antiquing solution to 10 parts room temperature water in a ceramic or plastic bowl large enough to accommodate your items.
- Submerge the items in the solution and agitate to remove air bubbles – if left they will produce bright spots on the metal, as air does not let the solution contact the item..
- You will notice the color develop in a matter of moments, at first a coppery pink that darkens through red brown and eventually a brown black.
- If you expect to highlight your finish you should let the darkening progress past the tone you ultimately want. If you prefer an even tone remove the item when it appears the right color.
- Rinse the item under hot water and clean off the powdery residue with a sponge or a scouring pad for an immediate highlighted effect.
- If the color is still too light simply return to the antiquing solution. If it is too dark then a scouring pad will quickly take you back to clean metal and you can try again.
- If you are satisfied with the color then dry the item quickly and evenly. Avoid leaving wet spots as these will invariably turn darker as they dry.
- The antiqued metal can be left as is, lacquered or waxed.
- If left unprotected it will continue to age – if you want the colour to stay the same, lacquer or wax it
Some notes on chemical mixes – these vary immensely. Some come undiluted, and require you to dilute them – if this is the case, follow the directions, and always use distilled water. If the recipe requires you to use a glass or plastic container, make sure it is very clean first, and use ones that are non-reactive. A decent, but not definitive guide, is if the item is microwave and freezer safe, it is generally non-reactive. And if it says nothing when you stand there and yell insults at it, it is also non-reactive… !
When you are scouring, don’t use steel wool, as fragments can come off and cause spots or streaks in your finish. Then when you are waxing, use Treewax, Johnson’s paste wax, or natural beeswax – even Tung oil works well. If you want to lacquer your item, consider that if the lacquer becomes scratched, you’ll need to remove the lacquer and start all over again, as an exposed spot will oxidize further than the rest of the item, and create a streak or spot.
For safety’s sake, whenever you are using chemicals to age your brass, always use rubber gloves without holes, safety glasses, and good ventilation. If at all possible, get a decent respirator.
If you are confident with chemicals, here is a summary table of the ones you can use to age brass, their finish, dilution and method.
Ammonia vapour is a great way to get a natural patina on your brass items – the old wive’s method of using urine or a dung heap is a related way of getting the ammonia – cheap, readily available, and about as natural as it comes … but of course, not to everybody’s ‘taste’! Warm urine is best, and varying temperatures of the solution give various effects. It was more usual to use horse than human urine, as their hay and oats diet means their urine is much richer in ammonia than ours. Wonderful! Burying the items in a dung heap is a similar theory to the urine one … it’s only grass, remember! If you can get past the psychological barrier, though, this is a simple, cheap method of producing a natural and realistic effect on your brass items.
In the same vein are various scientific, chemical ways of applying the ammonia to your brass items to age them, none of which involve your own bladder. Ammonia vapor produces a greenish brown oxide finish on your brass, like a coppery colour, and is said to be as close as you can come to a natural patina.
To age your brass items with ammonia vapour:
- You will need a plastic container with a tight lid. You can get the white ‘pickle’ buckets used by preservers and home-brewers from hardware and brewing shops, or any other well sealed plastic container will work.
- Cut a piece of plywood to make a shelf that will sit a few inches off the bottom. This shelf can sit on three blocks of wood to ensure it remains level.
- Clean your brass item and degrease it, definitely make sure it is not varnished
- Be careful not to splash the item with ammonia, this will produce spots on it.
- Pour a cup of full strength or “Clear Ammonia” into the bottom of the bucket, place the items for antiquing on the plywood and snap the lid in place.
Full strength ammonia can be obtained from architecture offices or print shops with “blueline” facilities, “clear ammonia” from the grocery store. (It is an extremely unpleasant fluid and should only be handled by competent adults in well ventilated areas or outside.)
An alternative method is to place your brass item in a large plastic bag with a rag soaked in ammonia – just make sure they are not touching each other, to avoid spotting and get an even finish. Also, if it is warm and humid, ammonia vapour can condense on the inside of the bag and run onto your brass, producing an uneven finish – so only use this method if you want a very light patina and don’t need to leave it in the bag too long. The time it takes to age your brass will vary from minutes to hours by this method, depending on the relative humidity, how warm and fresh your ammonia is, and what colour you want to develop it to. Check it often, but try not to inhale the ammonia vapour when you lift the lid off. Hold your breath and do it quickly. When the brass has developed to the colour you want, you can wax it if you like – beeswax is probably the most authentic sort of wax you would use for these items – as long as they are not doorknobs!
You can also use ammonia baths to age your brass products, if they are small enough to fit in a tub. Fill the container with common household ammonia, and put some copper pennies in the bottom – the more you can spare, the better! Put your brass fittings in there along with the pennies, but make sure they aren’t touching. Cover up the container, to create a decent seal. It doesn’t necessarily have to be airtight. Leave the tub overnight, somewhere away from children and pets … and check it first thing in the morning to see whether the colour has developed as dark as you’d like it to. If not, just leave it in a bit longer.