How to make bronze
A discussion started in 2002 but continuing through 20182002
Q. I'm 15 years old, and I'm wondering how do you make bronze. I know it consists of copper (90%) and tin (10%) which should be 9 parts in 10 copper. Is there any way I could use aluminum like soda cans? Please give me tips and techniques about bronze making.
Thank you,Matt [last name deleted for privacy by Editor]
- Henderson, Nevada
A. You need to melt the copper and add the tin to it. Aluminium cans will not withstand the temperatures and will melt before you melt the copper.
By the way, there is a wide range of bronze compositions, all with different colours. Low copper bronzes can be silver in colour, whilst high copper ones are a golden brown or even with hints of green.
You won't do it unless you have access to a furnace that can reach well over 1000 °C. Not only is this dangerous, but such furnaces are expensive to buy and run.
R&D practical scientist
Chesham, Bucks, UK
How to make bronze, etc.
Mr. Crichton: Your response was very interesting, brief and to the point. I had often wondered how to make bronze and copper etc and it was by accident that I came upon this site. I decided - in my own small mind - that you must be a man of distinction!~
Thanx very much.Ruth C [last name deleted for privacy by Editor]
- Santa Monica, California
A. Hello, post number 2 is incorrect with the temperatures, please DO NOT post if you do not know what your talking about, its very annoying. Anyway I just thought I would post pretty much everything you would ever want to know about bronze:
Bronze was developed about 3500 BC by the ancient Sumerians in the Tigris-Euphrates Valley. Historians are unsure how this alloy was discovered, but believe that . . .Matthew D [last name deleted for privacy by Editor]
New York, New York
Ed. note: the balance of this post was deleted because it is accurately reported below that it was simply copied and pasted from another site without attribution. If readers want to see the original content, please go to www.americanbronze.com/WhatsBronze.htm.
The actual author of the article, John Paul, was kind enough to log on and comment further on down the thread.
I am a 7th grader who needed to learn how to make bronze. Thank you Matt for asking that question so I wouldn't have to. Mr. D please be less curt.Aileen s [last name deleted for privacy by Editor]
- oakridge, Massachusetts
I do not appreciate your answer, as I understand you simply copied that text from another web page (www.americanbronze.com/WhatsBronze.htm).
What you seem not to understand is that brazing (what requires the metal to be heated below melting point, or 430° C (800 °F)) is simply how to join to other metals with bronze. This has nothing to do with making bronze, and I suppose if you had actually read through and understood what you were plagiarizing, you would already know that.Robert Z [last name deleted for privacy by Editor]
- Provo, Utah
! Whilst the second post in this thread may have been accurate and to the point I feel it was rather discouraging in its intent. A fifteen year old inquiring mind asks a question of people who have experience to offer and is told flat out not to bother trying anything as it can't be done. My personal experience is that most non-ferrous metals can be cast quite safely at home if a little research and a lot of care is taken.
If the first poster is still looking, I would start at www.theworkshop.ca .The owner of that site is helpful, insightful and above all else nobody tells him what he can and can't do.
- Auckland, New Zealand
Thanks for the link, Gregg! But I didn't read it your way whatsoever …
Trevor Crichton has extremely patiently and for no personal benefit whatsoever answered more than a thousand student questions here, often in exhaustive detail. Just use the search engine with his name as the search term to see his yeoman efforts. People who haven't yet borne the load of answering even a single student question themselves criticizing him for imperfection may not be a good idea: it could well make him question why he bothers when students rarely thank him but adults stop by to criticize.
We have 10,000 student questions on line here, with half a dozen new ones every day. If you and/or the owner of www.theworkshop.ca will please volunteer to try to handle a tiny portion of those student questions it would take a load off of Mr. Crichton and perhaps allow him to compose more detailed responses instead of being so constrained by time. Thanks again for the link!
Ted Mooney, P.E.
Pine Beach, New Jersey
Striving to live "Aloha"
Q. Okay guys, so here I am trying to recall the two main ingredients of bronze with the help of the internet. Got some more questions for any of you out there that may have an idea as to the answer. How do we know where bronze originated from, how did they figure that they could get it from ore, how did they build these furnaces and generate those kind of heats, was there residual materials that needed to be moved? A web link will suffice if I'm asking too many questions thanks.Glen [last name deleted for privacy by Editor]
- Manchester, UK
A. Dear Matt,
You've got the right idea, bronze should include anywhere from 10-20% Tin and the rest should be copper. What the rest of these guys say are right on as well. You will need to find a way to heat the copper up to 1,000 degrees or more. Tin's melting point is less than half of what coppers is (around 480 degrees), but even a stove top can melt it... but don't try that. I'm not going to pitch you a whole bunch of crap about how you should never do anything dangerous or work with hot fires, I did it in my youth and never got harmed, but that's only because I was EXTREMELY careful and was always in a situation where I could get help if I needed it. I don't care what you're doing with the bronze either, as long as you're being creative and not hurting others then who cares?
Good Luck with your smithing,Erick M [last name deleted for privacy by Editor]
- NYC, New York
A. I would recommend not using just copper and tin by themselves, but also adding a small amount of lead or zinc, or both. This will strengthen the bronze and give it a nicer finish.Harry C [last name deleted for privacy by Editor]
- Wellington, New Zealand
Q. I would like to know how much lead or zinc should be added to a mixture to make the Bronze?Cyrus C [last name deleted for privacy by Editor]
- Akron, Ohio
Q. I'm 13 and my dad & I are going to make bronze and I don't know what is right 1000° F or 800° F? Please reply soon.=)Danny L [last name deleted for privacy by Editor]
- Grand Marais, Minnesota
A. Hello, Danny! I don't think it's 800 °F; I think it's over 1000 °F per Mr. Crichton. But you've already learned that the internet really isn't an authoritative reference. Please try to visit a library and get help from the librarian if necessary to find the melting points in a metals book. You might find the cool charts of eutectic points and such interesting :-)
The American Society for Metals has a series of two dozen oversize volumes which comprise "The Metals Handbook". If you can find a library that has it, you'll be amazed at the exhaustive detail available. Good luck!
Ted Mooney, P.E.
Pine Beach, New Jersey
Striving to live "Aloha"
A. The melting point for tin is 449 °F. The melting point for copper is 1984 °F. Therefore, the melting point of bronze depends on what percentages of metal you're using; a high tin bronze will have a lower melting point than a low tin bronze. Hope that clears up any confusion; no one can tell you the melting point of bronze without first knowing the composition.Ben Friesen
- Duluth, Minnesota
Q. I would like to use bronze sheet to make a pair of chassis for valve (tube) amplifiers. If using steel I would use 16 gauge. I have two questions for you experts;
a) Which bronze would give me more of a rose colour, (as opposed to the bright gold of brass), and;
b) Would 16 gauge bronze sheet provide the same rigidity of 16 gauge steel, or should I go to a thicker sheet?
Many thanks in anticipation of your kind replies,
- Burbage, Leicestershire, England.
Q. I was wondering how to make bronze and happened upon this website. I'm 16 years old and my uncle (who's house I visit often) has a building full of tools, so I have a good bit of resources. I have plenty of tin and copper. I wanted to ask
1) How would I go about shaping the mixture?
2)How much of each material should I add to make a strong, durable bronze?
3)Would a blowtorch that reaches 1000-1500 °F work to melt these materials?
- Lanett, Alabama
Q. Hi I'm, well um, I'm nearly 13 and I want to make bronze. Could I make a fire in the ground and using a pump to blow air into the fire whilst adding coal could I reach about 1000 degrees °C? I would be using a crucible please help!
home - hereford, herefordshire, England
A. Hey Will just like yourself I'm 13 and to answer your question I don't think that well work. you might need a smithing kiln or an oven but I could be wrong. If so, someone please correct me.Zack H [last name deleted for privacy by Editor]
- Willmar, Minnesota
May 13, 2012
A. Anyone interested in metal casting and making home made alloys and tools should check out backyardmetalcasting.com. The man that runs the webpage is a hobbyist and provides plenty of useful info on the topic including how to make you own furnaces, crucibles, and casting sands. Perfect for the curious metal working mind in my book. Be advised working with molten metal is pretty dangerous though. I have had molten aluminum (melting point 1440 °F, easily attainable with charcoal and a hairdryer or a propane torch) explode from the ingot casting tray I was using (I guess dirt or some form of moisture bellow the metal) onto my face. Only burnt off a little of an eyebrow thankfully, but I quit casting until I purchased a metal hard hat to protect my scalp and a full face shield you can get from welding supply stores. You also want to make sure not to do this over concrete as even the driest looking driveway will have enough moisture to cause small explosions (personal experience) so a nice sandy spot in the yard would be the best place. With good safety gear this is a very fun and rewarding hobby. Go out there and have fun with it kids.David kirk
- Charleston West Virginia
A. I am 15 and for the last several years have worked in metallurgy with only a pit in the ground and have reached temperatures of up to and above 1500 °F using hard wood and some sort or blower weather a hair dryer or a small fan, the blower I use has varied depending on desired temperature and what I have on hand my fire pit is just a 5 inch deep by about 3 feet in diameter hole in the ground with a wall of bricks about 2 and a half feet tall around it and with that simple set up I have melted copper and gotten hot enough temperatures to make Damascus steel and as warned you should be safe because I have been burned and help from an adult is best to have.John W [last name deleted for privacy by Editor]
Ed. note: Thanks, John. That was terrific!
A. Wow. Lots of comments and recommendations. I created the article for American Bronze as a reference for customers seeking general information about bronze. As far as working with metals at home, no problem. Many people do that.
As far as making metals at home, I would think that would require a lot of research and effort to get the correct mixtures. Also using scrap would require getting impurities out of each before using them. Very time consuming.
I would recommend contacting a foundry that produces metals for the industry. We used Everdure Bronze for statues that has a specific copper, zinc, and some other contents. Other uses requires different percentages of ingredients.
You can purchase small casting tools and equipment online. The number one thing to remember is be very safe. Bronze melts at 1750 F and we would pour our products at 2250 F. At these temperatures contact with water would create an explosive action. Contact with your skin would be very very serious. Please DO NOT ATTEMPT WORKING AT THESE TEMPERATURES WITHOUT PROPER SUPERVISION, SETUP AND PROTECTION!
Otherwise, be creative, have fun, and learn.
- Deltona, Florida
A. Hi Guys,
If you want to smelt your own bronze, and just want to have a go, then this the following should be a good introduction.
This will lead to many questions.
In history bronze can be as simple as 90 percent copper 10 percent tin, or it can have precious metal in it such as silver and gold, with no tin to be seen at all (the Colossus of Rhodes was reputed to be made from this alloy called black bronze).
Adding more tin will lighten the bronze 80/20 (bell metal) is almost white (almost), but is brittle, and will shatter with thin castings.
So for your purpose stick with the 90/10, this will make a very durable bronze that has a goldy-brown colour, good for jewelry, and other items.
This is something I created to test refractory materials :-
And this is probably as cheap and uncomplicated as bronze smelting can get.
The furnace body shouldn't cost you more than $20, the crucible $13 (and is the smallest one I could get... just a materials test remember), the tongs $13, and the expensive component is the JTH-7 Bernzomatic hose torch, and adapters to fit it to a standard BBQ cylinder. You can borrow the BBQ cylinder from your Dad ;-)
The furnace body is made from a milk powder can (about the size of a coffee can), a K26 fire brick, padded with some hi-duty kaowool, and sealed with some zirconium paint (you could use kaowool hardener here instead of the paint).
If you decide that you don't like melting metal and casting metal, then you can give the heating components to your Dad next Father's day, and give the furnace to a friend.
** Caution: This little furnace gets very hot very quickly, the melt point of bronze is 800 °C, but the flow point is 100 - 200 degrees hotter.
** Note: Please season your crucible first, or it will shatter (see a question about seasoning crucibles).
The procedure for this furnace for bronze is as follows :-
1) Fill your crucible to the brim with Borax [linked by editor to product info at Amazon], and then tip it out. This lines the crucible with "flux" and makes the metal flow nicely.
2) Put your tin into the crucible (I like to do this first, as the tin effectively lowers the coppers melt point).
3) Your copper goes into the crucible next. The best type of copper for this operation is granulated, but small pieces will do as long as the tin is covered. Put some more borax on top.
5) Light your furnace, and lower in your crucible (with tongs), put the lid on the furnace. Check in about three minutes time.
** The following is an old trick that works, but if you don't feel comfortable with it buy a graphite stirring rod.
6) Your bronze should be molten or very close. Get a green stick (not a wet or turgid stick), and use this to stir your alloy. The impurities will stick to the green stick. As an added bonus the stick will turn to charcoal, and can be used as a stirring stick until it disintegrates.
7) Your bronze is ready to pour into your mold (and that is a big topic too).
Oh and I can't state this enough, although the furnace is small, it can still burn you very badly. If you don't feel confident don't attempt this.
There are many casting groups on the net that will gladly assist you in this hobby.
- Mortdale, NSW, Australia
I was looking on how to make bronze for a school project and this was a site I found and it helped (some)Bekah H [last name deleted for privacy by Editor]
- Hilliard, Ohio
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