Introduction: Mirror Finishing a Metal

Picture of Mirror Finishing a Metal

Sometimes its really difficult dealing with metals like copper and brass (Two metal that we'll be dealing with) . Mirror finishing a metal like the copper plate I have shown in this Instructable, isn't really hard or difficult to achieve, especially when your projects requires metal parts. A dull non-finished metal part look's tacky than an well finished part. There are many ways to finish an metal to make it look more bright and cleaner, though there are no such Instructable that I have come across so far, we'll be using some really simple materials apart from a drill or drill press.

Materials needed:

Scotch pads
Sand paper of 400, 600, 800, 1000, 1500 and 2000 grid.
3m polishing compound or any other polishing compound.
Polishing wheel or buffing wheel.
Soft tissue (Soft toilet papers works best cause they are really soft).
Sterile rubber gloves (Optional)


Drill press

Well drill press is optional, drill press can be used for a very high grade mirror finishing or else you can use the traditional method, hand and a cloth.

Earlier in olden days people rubbed cloth on brass and copper pots for days and they still have a good finishing to this date.

Step 1: Heavy Metal.

Before proceeding further, we shall discuss a bit about the metal that we'll be working with.
Major problem, Metal poisoning.
Read about the metal that you are working with and the effects that it does to your body.

Copper and Brass.
opper is an toxic metal and so is Brass( Mixture of copper and Zinc, again both are toxic).

Copper toxicity, also called copperiedus, refers to the consequences of an excess of copper in the body. Copperiedus can occur from eating acid foods cooked in uncoated copper cookware, or from exposure to excess copper in drinking water or other environmental sources.

More about Metal toxicity:

Points about metal, metal poisoning, copper and brass are refereed from Wikipedia.

Step 2: Let's Begin.

Picture of Let's Begin.

Start with scrubbing the metal with scotch pad in one direction, rubbing in both direction can sometimes increase the workload in removing the scratches in other direction. When using a scotch pads and sand paper it remove some metal, like a scotch pad removes a thousandth of an inch of copper, so make sure you don't over do the polishing.

Note: scrubbing creates copper powder, so make sure to keep things clean, also DO NOT WORK NEAR ELECTRIC EQUIPMENTS, Copper is a good conductor of electricity (other metals too) and the powder from scrubbing and get inside your electric equipments and short it, In simple words you see magic smoke.

Step 3: Order of Work.

Picture of Order of Work.

I have arranged the process in a much simple step.

1. Rub scotch pad
2. cleans it with Acetone and cloth or tissue
3. Rub with 800 grid sand paper
4. Repeat step 2
5. Rub with 1000 grid sand paper
6. Repeat step 2
7. Rub with 1500 grid sand paper
8. Repeat step 2

Step 2. "Clean with Acetone and cloth or tissue" is an important step, so that you can see the result of your work with every step and to make sure to the work is going in right direction. Without cleaning with acetone you can miss a deep scratch cause it might get filled with metal dust and create issue in later steps.

Step 4: Crucial and the Best Part.

Picture of Crucial and the Best Part.

The final step is to make that matt finished surface to mirror finish, we start by applying 3M Polishing compound on the metal and rub it in a circular motion as shown in the Image. Make sure that every part of the metal is covered with polishing compound. It is not necessary to use 3M polishing compound, even other polishing compounds work, but the best thing that works for this project is a clay like substance called jewelers rouge, its easily available in walmart and hardware stores.

Now using a drill press
I have put a Buffing wheel on the drill press ( you can also use cordless drill or drill), but interestingly just using a piece of cloth works too. Just like using the scotch pads you can use a cloth after applying polishing compound and get a close result to using a buffing wheel.

Step 5: Are You Satisfied?

Picture of Are You Satisfied?

Well I wasn't!!

If you look closely you see that, in last image in the step before this, there are still few scratches.

So what do we do?
Very simple

Repeat the entire process again. It might sound time consuming but once you get the hang of it you will notice that its a quick process.

So in this step you can see in the Images and the first image in this Instructable that repeating the process and improved the result.

Step 6: What Else Can Be Done?

Picture of What Else Can Be Done?

Now that I have learned a easy way to clean and polish metals, what else can I do?

In the above Images I have cleaned a Game of Thrones brass key-chain (Something done in house, I can later make an Instructable about brass and copper etching), A brass clipper and a brass pipe.

More about pipes and circular objects.
I have used a little different method the clean the brass pipe.
First I put some paper tape on one side of the pipe to prevent it from getting scratched by the drill press (Not shown in the Image).
Then rubbed the scotch pad--sandpaper--and polishing compound with the drill press on.
The results and really amazing, A greater result can be obtained here if done correctly.

Step 7: What Have I Used This Method So For?

There are so many used, but what have I done.

Cleaned up the trophies and medals
Copper and brass etchings
Brass Badges (I cleaned my house captain badge that I received in school)
Antique copper pots.
Even the metal clipper on my Pen!!


Varen Greycloak (author)2016-09-20

hmm, going to try this with sheet aluminum.

toasterizer (author)2015-04-21

Very good ible. I have to say I cringed at the picture that showed the drill press being used by a gentleman wearing a necktie. Drill presses and neckties are a very scary combination.

ygujarati (author)toasterizer2015-04-22

well I'm still in school, so any free time or breaks then we get, we rush to the "Design and Technology lab" to get the work done.... I will try to minimize that from now.
Thanks toasterrizer .

Void Schism (author)ygujarati2015-04-22

Perhaps you should have a word with whoever is in charge of safety. Nothing with risk of constriction or trapping should be worn in a workshop. When I was at school we had to remove our ties before the teacher would power the machines. Sometimes even gloves pose an increased risk over handling materials bare-handed.

gaieb (author)Void Schism2015-06-17

Example, my grandfather was cleaning the husks out of a corn picker, left it running as he had many times before. It caouht the end of the thumb of the leather glove and pulled his thumb into the rollers, he yanked it out, but it left the lower joint of his thumb in the machine, would have probably been safe without the glove,

I know, he shouldn't have left the machine running, so don't bring that up. The fact is because of the glove being able to catch on something resulted in the lost of his thumb. gloves are not always safe.

DDW_OR (author)ygujarati2015-04-26

if you have a dress code in school, tuck the tie in your shirt, and role up your shirt sleeves. maybe use a large rubber band to hold sleeves in place, but this may leave creases.

lazemaple (author)2015-04-26

is there something less toxic than acetone to use for step 2?

ac-dc (author)lazemaple2015-04-26

Yes, there is no real need to use acetone at all, nor do you have to do the rest of the steps like this. Try these two steps instead:

1) Wet sand the part in detergent solution using progressively finer grit sandpaper. Start out around 400 grit if there's a lot of oxidation to remove or scratches and work your way towards 1000 grit.

2) Brasso or other similar metal polishes have a micro fine abrasive that polishes the metal and removes any contamination like greasy fingerprints. Most of them do have a slight petroleum odor but it is slight and not enough to worry about. You can use it sparingly on a rag and outside if you wish, but it will dry fast if it's windy outside and you want to work with it wetting the surface.

Also note that many metal polishes have a very mild acid to help dissolve oxidation, so in some cases there is no sanding needed at all but a power drill or polisher would still make the work go faster than doing it by hand.

ac-dc (author)ac-dc2015-04-26

Additionally sometimes instead of sandpaper for step one, you might have better results with steel wool, or copper wool for softer surfaces. Like the sandpaper it also comes in ranges from coarse to fine.

andrew.mead.1253 (author)ac-dc2015-04-28

"Copper wool"? I've never seen that. Does it really exist or are you mistaken?

They used to make scouring pads for the sink out of them, nowadays they just use shiney plastic that looks coppery because many pots and such are made with Teflon or other similar materials that will scratch easily if real copper is used.

We call it Copper gauze at work.

ygujarati (author)lazemaple2015-04-26

Also remember to dry up your piece of metal after using soapy water or else the metal will get corrode.

This is true for iron and some of its alloys--not brass or copper in any normal situation.

hexanerax (author)lazemaple2015-04-26

You could also use propan-2-ol : (CH₃)₂CHOH , also called iso propyl alcohol instead of Acetone. Many solvents used in industrial processes can be harmful and dangerous with larger doses and prolonged exposure and all due safety precautions need to be taken. Acetone is not as toxic as a post on this thread seems to suggest . Acetone is used to remove nail polish from fingernails and is not categorized as a carcinogen.

I agree, this is much better than acetone for the purpose discussed. It's also known as "wood alcohol" and methyl hydrate here in Canada. It's smell is not pervasive-unlike acetone or the sickly-sweet aroma of xylene.

Michael013 (author)lazemaple2015-04-26

Acetone is fairly non-toxic, as solvents go. Your body can even turn it into glucose.

lazemaple (author)Michael0132015-04-27

So are you saying we metabolize it? That is a scary thought!

Michael013 (author)lazemaple2015-04-27

Google "Ketogenesis"

ygujarati (author)lazemaple2015-04-26

You can use warm soapy water, Dish washing liquid soap works just fine.

sergeiepp (author)2015-05-13

I advise to bring to a mirror finish using plasma electrolytic method. This method during 3-5 minutes to improve the roughness of 2-3 class. For more information about equipment and methods can be read here

JesseM2 (author)2015-04-26

You know what works really well on copper is Soy Sauce... No joke, pour soy sauce on the copper and let it sit for about 10-20 minutes and wipe it clean. Literally takes away any oxidation that may have ocurred throughout that piece of metal's lifetime. buffing it is a diffierent story, I'm just saying this will make your copper look brand new in minutes with absolutely no work whatsoever.

andrew.mead.1253 (author)JesseM22015-04-28

The effect of the weak acid found in Soy Sauce (and most other condiments) will by no means approach the desirable effect occasional to the abrasive treatments proposed and discussed.

JesseM2 (author)andrew.mead.12532015-04-28

Well I can say that it made it look pretty damn brand new to me. I didn't scrub or anything it just spilt and I wiped it away later... looked like a brand new penny.

bettina-sisr (author)JesseM22015-04-27

Also tomato paste works great to clean up old dingy copper, not sure about the polishing part though. Smear it on, rub in, let dry, wash off:-)

ygujarati (author)JesseM22015-04-26

Never heard of it or tried it before but now sure I'll try it.

Thank you

JesseM2 (author)ygujarati2015-04-26

NP I found out by accident and just to let you know it was "Low-Sodium" soy sauce... Might have something to do with it but definitely let me know what happens.

rogersba17 (author)2015-04-26

For starters I'm going to repeat what everyone else has said and say no long sleeves, neckties, necklaces, long hair, etc around anything rotating... You will die, or worse, have to live with what has happened to you. Second! Sanding in one direction is like wearing a necktie around something spinning... You're gonna have a bad time.... What I've been taught is to make small circles with a fine sand paper that has been dipped in soapy water, the soapy water cleans the sand paper and removes the particles that have been rubbed from the material. Next if you'd like to make sure you corrode your material you rinse it with a quick drying solvent, rubbing alcohol will work just fine, and it won't burn through rubber gloves, next when you use a rubbing compound, again small circles with a cloth, you can use a micro fiber cloth but regular fabric shop rag works great from experience, and an easier way to get that nice shiney finish is to use a buffer, it's a big flat foam surface that rotates. The small concentric circles really make everything look great and you won't see them in the sun. Enjoy!

Rodeodog (author)rogersba172015-04-27

I take exception to what you said about sanding. The small circles is just extra work. The soapy water is necessary to clean the metal between sand paper grits, however, when you change sanding grits, you should change the direction of sanding by 90 degrees (this will highlight the previous grit scratches and show you when you are ready to progress to the next grit). When we used the polishing compounds we generally used acetone or methanol to clean the specimen because it was faster and better at cutting through the compound. Methanol became the choice because of bulk buying and less flammable spontaneity, or so I was told.

The soapy water process is, I believe, known more accurately as "de-greasing".

ygujarati (author)rogersba172015-04-26

You wrote an Instructable here!!. Thank you for the guide. Also have you tried electro-cleaning or other methods of cleaning metal? some more help will do great.

Thank you once again.

andrew.mead.1253 (author)2015-04-28

Over the decades I've used everything from chalk powder, Brasso, Jewellers Rouge to ( as of last week) fibreglass insulation to polish objects composed of soft metals. It's not a hobby but I enjoy it and the creativity involved using abrasive mediums to abrade and burnish metal objects. 3M has an amazingly good line of "cutting-edge" technology products for cleaning and polishing. I use acetone and xylene without gloves and have washed my hands in xylene when the going got tough. I have a friend who happens to be a jeweller. I was shocked to hear that he used benzene in his family business and had for over 60 years. Both he and his brother are retired since 2013. One's 85 and the other, 88. Neither have had health problems of any note. By the way, I'm in regular contact with lead and its alloys and have been working with it for precisely 30 and a half years without ill-effect-save the occasional descent to bouts of insanity and months-long periods of violent retching..... ( just kidding-couldn't resist, etc.). That being said, I would never work with Mercury- not because of the danger involved but the realization it's always polished and impossible to grab hold of.

lazemaple (author)2015-04-27

I wouldn't call potential for lung irritation and kidney damage nothing to worry about... granted that is when inhaling large amounts then again each of us has higher and lower thresholds than another, and given the number of repeat uses to polish the metal I prefer something with little risk potential

Some excellent info here

As it happens I'm highly sensitive to all solvents so thank you for the suggestions for alternates to use

zacker (author)2015-04-27

...And once its polished, you really don't need to do all this again, just use a little brass / copper cleaner / polisher on a very fine steel wool pad. Or, use that stuu called "Never Dull" its a wool like material with some sort of polish / cleaner on it, it comes in a can, you tear off a chunk and rub the item with it until its clean. works great.

steve.oakley.10 (author)2015-04-26

I tie and a drill press ? thats a death wish. long sleeves are almost as bad. saw a guy get flipped over from one side to another by a lathe when shirt got grabbed. happens in a instant.

zacker (author)steve.oakley.102015-04-27

A girl a few years back, I believe at Yale got her hair caught in a metal lathe while working alone in a metal shop and got killed. Its crazy what can happen. Ive had my chest torn up prtyy well by a regular wire wheel in a hand held drill when it got caught up in my sweat shirt while I was stripping paint off a small part that I held too close to myself.... it happens in an instant!

Amnesia Wes (author)2015-04-27

Instead of using my drill press, I bought a larger buffing wheel and put it on my bench grinder. Quicker and easier to work with.

mndietz (author)2015-04-26

What do the warnings on the can say?

tovey (author)mndietz2015-04-26

Don't use to mirror finish metal.


Not really: I just couldn't resist.

mndietz (author)2015-04-26

Be very careful of the acetone. It is extremely flammable, goes through most "rubber " gloves, and causes cancer.

Wild-Bill (author)mndietz2015-04-26

Yes, Acetone is dangerous and should be handled with caution. Do not get it on you skin and always wearing latex or nitrile (better choice) gloves when handling it and only use in a very well ventilated area and wearing a chemical mask is also recommended. I like the way it can clean up hardened fibreglass resin. I handle Acetone the same way I handle Xylene which is way more dangerous.

Really nice project - can see doing a cool steam punk project using some of your techniques.

Flammable, yes, but I have never had acetone penetrating my rubber gloves. Then again, I almost always handle acetone without any gloves, since, according to current concensus, acetone is not a carcinogen and not even that toxic.

See e.g. Wikipedia:

"Acetone has been studied extensively and is generally recognized to have low acute and chronic toxicity if ingested and/or inhaled. Acetone is not currently regarded as a carcinogen, a mutagenic chemical or a concern for chronic neurotoxicity effects.

Acetone can be found as an ingredient in a variety of consumer products ranging from cosmetics to processed and unprocessed foods. Acetone has been rated as a generally recognized as safe (GRAS) substance when present in beverages, baked foods, desserts, and preserves at concentrations ranging from 5 to 8 mg/L.

Acetone is believed to exhibit only slight toxicity in normal use, and there is no strong evidence of chronic health effects if basic precautions are followed."

billbillt (author)2015-04-26

Don't let the "Health and Safety" police disrupt you from your endeavors... They are always on guard patrol here looking for things to criticize.. Great job...

The Lightning Stalker (author)2015-04-26

Meet shetal

chalawandan (author)2015-04-21

Nice ible. You can use the same techniques for motor parts - I've seen some engine bays where dedicated owners have spent an age polishing various metals to a chrome like shine instead of paying for lots of chrome work.

rogersba17 (author)chalawandan2015-04-26

Sorry to break it to you, but if they don't continuously shine these things or put a clear coat over them they will tarnish very quickly.

jgriffiths12 (author)2015-04-23

Try white diamond. it's well known with truck owners a little bit of effort with a microfibre cloth and it can turn a dull unlaquered aluminium wheel or fuel tank into a mirror it's not cheap but you get what you pay for

Mario2007 (author)2015-04-23

Horrible things have happened to people wearing long sleeves, neck ties, long hair, and necklaces around drill presses and lathes. I saw a pic of a man turned to hamburger meat because of such a thing. Shop safety is very important and should be enforced.

d_salce84 (author)2015-04-23

I'd say finish it off with semi chrome. Also everytime you to change to a different sanding grit use it in a different direction. That way You can make sure you removed the previous scratches.

dshrimpton (author)2015-04-22

can this be used on aluminium

About This Instructable




Bio: I'm a student, studying Engineering. I'm learning electronics, robotics, wood working and science in general. I enjoy hacking and disassembling as much as ... More »
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