View Full Version : building bronze


kyle juedes
10-09-2004, 09:56 PM
Just for the sake of giggles: Can you take brass and aluminum and melt them together in a forge to get bronze?

Thanks,
KJ

kyle juedes
10-09-2004, 10:01 PM
Actually i meant copper and aluminum, but i think that i've heard of alum-brass bornze too.

KJ

mete
10-10-2004, 07:18 AM
There are various copper/aluminum alloys but making them yourself is not a good idea. BTW zinc fumes are toxic .

Geno
10-10-2004, 12:01 PM
Copper, tin and zink make bronze.
Copper and zink make brass.
Tin and zink make pewter.
Hope it helps.

hammerdownnow
10-10-2004, 12:39 PM
Yes but will aluminum and copper mix? Will you need zinc?

Geno
10-10-2004, 02:05 PM
You might look into a nickel aluminum bronze.
I don't think you'll have much luck trying to mix al and copper. :o

kyle juedes
10-10-2004, 10:11 PM
Well, even if it didn't mix, it would me neet to add them together and then swirl it around a little, and let it harden to get some kind of pattern. Would this work?

kyle juedes
10-10-2004, 10:19 PM
If you need zinc to mix it, how did they do it "back in the day"? I mean how much zinc did they have laying around in the Dark ages? By the bay, I really don't know what i'm talking about, so please correct me if i'm wrong.

KJ

kyle juedes
10-10-2004, 10:33 PM
Ok, i've posted 3 times in the last 10 minutes. Sorry i have questions! Well, 6061 aluminum, which form my under standing is one of the most common aluminums, has only .25% zinc. Would you really experience the effect from it with such a low percentage? Also, this is off-topic, but how can you heat tread 6061 with out getting zinc poisoning? Would a resperator protect agaist zinc fumes?

Thanks,
KJ

AwP
10-11-2004, 03:54 AM
If I remember right, zinc poisoning is culmnitive, meaning that it stays in your body and builds up over time. That little bit might not hurt right now, but in a few years maybe you accidentally put something in the forge with zink in it, then a few years after that you want to burn the galvinization off of a pipe, then a in few years... anyhoo, I think you see my point, the less you put in your body the better because even tiny bits add up. A resporator might completely solve your problem, I'll let someone else answer about that, I'm not overly familier with them.

george tichbour
10-11-2004, 06:37 PM
I would imagine that there would be some sort of flux required to keep the aluminum and copper from oxidizing during the melt process then to promote mixing given that there is such a large difference in density between the two metals.

Metal poisoning is indeed usually a cumulative situation but the body also tends to remove toxic metals through the kidneys over time as well so OSHA has posted maximum safe exposure levels for most contaminents.

chipwit
10-12-2004, 06:15 PM
I've made aluminum bronze a few times in my little gas forge, and it is very easy. Just put copper and aluminum in crucible and fire away. It is good to cover the metal with borax or charcoal to protect from oxygen (esp. the Al), but I think the first time I tried I got away without any flux. I used 90% Cu and 10% Al but you can use just about any ratio you want. It comes out a brassy color but brighter, at least with the ratio I used.
Good luck-

kyle juedes
10-12-2004, 06:37 PM
Would a steel tray work for a crucible? Will the two metals melt together on their own, or do you have to mix it with something?

Very useful post Chip! thanks

KJ

chipwit
10-12-2004, 08:13 PM
I know that stainless steel is used for bronze, so I would guess that any steel would work, iit just won't hold up long.
If you have a 99 cent or dollar type store around, they usually sell stainless bowls, coffee creamers etc. A clay flower pot, or any kind of porcelain cup or container would work too-
Is the steel tray all you have? If you can get a cylindrical crucible it would be better because the metal can be completely covered with charcoal or borax and not get exposed to oxygen, but the tray should work. And they will melt together on their own, but adding borax helps metals to fuse.

kyle juedes
10-12-2004, 08:51 PM
Where can i get my paws on some borax? Is it readily availible or do you have to special order it? With the charcoal, so you just make it into a powder or what?

Thanks,
KJ

hammerdownnow
10-13-2004, 04:12 AM
In the laundry soap section of the grocery store. Do not buy Boraxo. Buy pure 20 mule team borax. Or use the dust in the bottom of your charcoal bag. Keep us informed on your findings. thanks, Roc

chipwit
10-14-2004, 01:17 PM
Roc- You can usually get borax at the grocery store in the laundry detergent aisle and it's called 20 Mule Team. With charcoal just crush it pretty good and it should work. Mine was
pretty coarse with some pieces over 1/4" but finer would be better I think. As long as there is a layer deep enough to react the oxygen before it can get to the metal you're fine, but I don't have any data. It helps to put the aluminum on the bottom since it reacts more with oxygen than the copper and there is less oxygen at the bottom.

kyle juedes
10-25-2004, 09:29 PM
Ok.. I have a bunch of brass and alum.. Will brass and aluminum mix to make bronze? or do you need copper? I can't find much copper besides piping. Are pennies pure copper or are they alloyed?

Thanks,
KJ

mete
10-25-2004, 09:47 PM
New pennies are a sandwich - copper rich outside , zinc inside. Aluminum bronzes have copper and 5-10% aluminum....Zinc fumes will make you sick immediately, it's things like lead and other heavy metals that are cumulative.

hammerdownnow
10-25-2004, 10:21 PM
Copper pipe is great, It has to meet a certain purity standard to be used to run water. I have heard it is the best sourse for pure copper. DON'T USE PENNIES!

kyle juedes
10-25-2004, 11:27 PM
Ok, thanks alot. I'll use the pipe and aluminum. i'll probably go with the charcoal, since i can get it for free. Can i use coal from burnt wood? Because that would be REALLY cheap. If there is charcoal on top of the mix, how can you tell when it's melted?

kyle juedes
10-26-2004, 12:06 AM
See... This is why i'm shying away from piping. It's melting point is 1980 F! :eek: I'm working with a small coffee can forge with a propane torch. 1980 is really pushing it! I might upgrade to MAPP if i can get any money.. but even for MAPP this is HIGH. :confused: Would a hair dryer boost the temp enough with propane?

hammerdownnow
10-26-2004, 12:14 AM
Propane plus air will melt steel! What is the melting temp of aluminum?

hammerdownnow
10-26-2004, 12:20 AM
Charcoal and air will get very hot too. It might be yor best bet if you get it free. what do you get? Lump or brickette? Eather will work for what you are doing. If you need plans to make an effecient charcoal forge with a blower, let me know and I will post a link.

kyle juedes
10-26-2004, 12:26 AM
I'm probably sure that my parents wont let me have a coal forge. Their already iffy on the torch-forge. Alum melts at 1000. I could probably get bickettes from my neighbors. So, a hair dryer and a torch will melt copper for sure?

Thanks,
KJ

hammerdownnow
10-26-2004, 12:46 AM
Depending on how you set it up. Messing with propane and alternating the original funtion of a torch is dangerous and should only be done by someone with experience with such things.

How about a wood fire? Charcoal is just wood with the water cooked out of it. When you when you set wood on fire and all the flame is gone and just the coals are left, you are then burning charcoal. When you add air it makes the charcoal burn faster and hotter. Look at this tutorial on makeing a forge in a barbeque grill and then tell me if it would be fesable for you to do something similar.
"Forge-b-que" (http://www.taigoo.com/tutorial/frameset.html) click on the pic of the barbeque grill and look at the pics.

kyle juedes
10-26-2004, 10:06 AM
Like i said, i don't know about a coal forge. I can deffinitely make a fire though. My first three blades were heat treated in my fireplace. The last blade took me a good three hours to get a good even heat on the knife :eek:. But, maybe a hairdryer would decrease that. The only problem i can see with a fire is that:

1. The whole purpose of me doing this is so i can cast a ring for a freind and to cast a couple "blocks" so i can grind them into guards. I don't suppose casting is very safe at all to do in the house. And i suppose my parents would shoot me if i did it! ;)

2. since the aluminum has zinc, don't you run the risk of getting a bunch of zinc fumes in your house?

I'm limited in my ways to work becuase i live in a city, so i don't have much room to work with. How is Adding air to the torch altering it? I was going to have the torch on one side of the forge and the hair dryer pipe on the other. This way i dont have to alter the torches opperation to have air.

hammerdownnow
10-26-2004, 10:16 AM
Not sure how that would work. From my limited knowlege the air and gas need to mix before combustion. I see your deliema. Here is a link that mght help confuse you more.
backyard metalcasting (http://www.backyardmetalcasting.com/)

R. Lemmen
10-26-2004, 02:11 PM
Just for added emphasis, a personal story:

When he was much younger, before the age of environmental restrictions, my father breifly worked at a zinc smelter in The Netherlands. At the time the people of that town called the factory "The Still (quiet) Dead". No one who worked there lived long past forty years old. Zinc fumes are nasty and should not be treated lightly. Luckily, my Father only worked there briefly and has suffered no ill effects.

You do not want to cast any metals INSIDE your home!!! Do it in a well ventillated shop or in an outdoor area a good distance away from combustible materials.

Cheers,

Rob

chipwit
10-27-2004, 04:00 AM
Kyle- If you have access to an area where you could dig a hole and have electric power to run a hair blower, and you have enough charcoal (real charcoal, not briquettes), and a pipe (big enough to carry the air blast from a hair blower, you can melt steel if you want to. I haven't done it but I would think a hole 1.5' deep by a foot wide would be enough, and rig up the pipe so one end enters the bottom of the hole (you will have to obviously need to bury part of the pipe) and direct the blast from the blower into the above ground end of the pipe. I make my own charcoal but dry wood will work too, the more dense, the more heat it will produce. I converted my smoker/barbeque into a forge by just running a pipe into it and I now use a cheap shop-vac as a blower (with dimmer switch to control the blast) and I have often melted steel when I had it too deep for too long. The only drawback with charcoal is that when melting stuff, the fire consumes prodigious amounts of charcoal (or wood), so if you go this route, you will need to have plenty on hand.
BTW- aluminum contains no zinc unless you have some weird alloy- and for what it's worth, I have made nickel silver by melting 2 new pennies (zinc core) and 7 nickels.
I also burn the zinc off galvenized wire for making damascus in my ventilated garage, (in a propane forge) but I exit the garage while the zinc is burning (burning zinc gives off copious smoke and a distictive blue flame) and don't reenter till it's done. All this stuff is dangerous- you just have to use common sense and educate yourself beforehand as to the risks. Melting brass gives off toxic zinc fumes too- but people cast it all the time.
Despite the current safety hysteria and alarmist attitudes, common sense and knowledge
will allow you to work with zinc, mercury, even lead! This whole ultra-safety thing reeks of PC to me- enough of that, pardon my rant. Good luck!

kyle juedes
10-27-2004, 09:21 PM
Who know what temp brass melts at? I've heard 1630 from Metal suppliers online, but then have heard 1750-1800 from various casting websites. I think i could hit 1630 in my forge, but probably not the latter.

Will Alum and brass melt together? can you make alum-brass bronze? If it doesn't melt together, just out of curiosity, i you swirl it will you get a damascusy pattern in the final result?

Thanks,
KJ

chipwit
10-28-2004, 01:55 PM
Kyle-
I just got this off the first site I got with google: "The melting points of these alloys vary from 1680F to 1850F or so".
On the brass and aluminum, I'm sure it would work, and I'd bet that there are alum. bronzes with zinc, which equals brass + alum. When I made bronze and alum bronze, I didn't stir and it seemed to be pretty well mixed, but stirring is probably a good idea.

kyle juedes
11-07-2004, 06:38 PM
Here's the results:
http://serv1.freeimageupload.net/uploads/1099870536.pjpeg
http://serv1.freeimageupload.net/uploads/1099870663.pjpeg

I cast the ring for my freind, a guard and a pin for a knife.

Thank you all for your help.

KJ

hammerdownnow
11-08-2004, 12:31 AM
What metals did you use, and what were the ratios? In the pic it looks like three different mixes.

kyle juedes
11-08-2004, 09:52 AM
yea. The metals are all the same ratios (probably aout 1 to 6), but the longer i kept in in the forge the darker the color got (I only had time to pour one shape at a time, the pin bieing the last). I'd suspect that more and more zinz burned off, so i got a highher and higher Cu to Al ratio. Even with the color change, i'm very happy that it worked at all. oh and i used brass and aluminum.
KJ

hammerdownnow
11-08-2004, 10:09 AM
I like the coppery color the best. I think I will try it with alum and copper. Thanks for the update. Cool little foundry.