Casting brass

[Malcolm Schweizer]

I have read quite a bit on pouring metal, and enlisted help from a friend who does it professionally. I still have not gotten the "brass balls" (pun intended) to do it myself. My friend recommended the book "Build Your Own Metalworking Shop from Scrap: 1 The Charcoal Foundry." This guy builds a lathe from scratch, and then uses it to build all his other machines. If ever stranded on an island... Wait... Just remembered that I AM stranded on an island!

Question for George- how do you mix the metal when making your own bronze to ensure an even blend? Do also post pics of that chariot plane, please.

[george wilson]

You can give it a quick stir with a steel rod. Doesn't need much,and I hardly ever bothered to stir my bronze. It seemed to even itself out.

The chariot plane is very tarnished and looks bad. I need to polish it up.

[Don Rogers]

When I was 15, I worked part time in a Plumbing Supply Store. Occasionally I would work with one of the plumbers as a helper. One job was in a basement having a dry concrete floor and the plumber ask me to get the lead furnace and heat up some lead for a cast iron joint he was going to caulk. I set the led furnace on the concrete floor, pumped it up and proceeded to heat up a full crucible of lead. I also put the cast iron ladle on the concrete floor near thee furnace.


When the lead in the crucible had melted it had some dross covering it and I decided to skim it off with the ladle. Big mistake. As soon as the ladle touched the molten lead, there was an explosion that entirely emptied the crucible of molten lead. Some lead covered my grease laden overalls, some splattered on my face, and some got on the plumber and the lady of the house who was just coming down the basement step to see how we were doing.


Fortunately, none of us were seriously hurt, but the plumber was visibly shaken as he said “ I should have told you to put the ladle on top of the furnace to drive off any moisture before dipping it into the molten lead.” I didn’t know any better.


I was not aware of this problem - after all the ladle was dry and it was laying an a dry concrete floor - how could it have any moisture in it. Besides, how could a little invisible moisture cause such an explosion.


It did and I learned a valuable lesson that day. Ever since then, I’ve occasionally wanted to make my own brass and aluminum castings but this memory always resurfaces and makes me think twice about doing so. Molten metal is nothing to fool around with if you don’t have the knowledge and proper safety equipment .


I hope this story helps someone.

Don

[Steve Voigt]

…

Given the price of brass right now, it likely would cost you less to buy a few cylinders if you're looking to make hammers (I am). I just bought 2" cylinder 4" long, a 1.25", 3" L and a 3/4", 3" long for under 20 dollars.

If you want to do it for the experience, go for it. But I impress upon you this is dangerous. A liquid at quantity at >1700 degrees is not to be trifled with. Please take all appropriate safety precautions. UV eye protection is a must. You can fry your retinas real quick. Super hot vapor or gas does not do good things to the lungs either. Do not do this on concrete - cast on a floor of sand or dirt. Do not add cold material to the crucible with headed metal in it. I sure I am forgetting some important safety items so please do the appropriate research.

An excellent, informative post, Sean. One followup question: I have recently been doing some very basic forging/heat treating/ annealing with a charcoal forge (a truck brake drum fed by a woodstove fan). Do I need UV protection for my eyes? If so, what would you suggest?

I sure agree about the price of brass. Once you add up the price of casting materials, fuel, safety equipment, etc, the cost of casting a few hammer heads will be many times the cost of just buying a suitable chunk of material. The head on my plane mallet is 3/4 brass hex and cost me a whopping $2.50.

[Charles Wiggins]

I was thinking of (carefully) making a wood rectangle the size of the casting I want then putting some wet play sand in a wood box, pressing in my form and then removing it so the mold would be open at the top, a very simplistic approach which would lead to a very rough casting.

Bad idea. At the temps you have to heat brass to get it melted you'd be asking for steam explosions. Any trapped moisture will vaporize to steam instantly and trapped steam will find it's way out and take a lot of molten metal with it. The only saving grace might be that sand is porous, but with the amount of moisture it takes to make play sand hold its shape I'm certain you'd be in for fireworks.

A better solution would be to use an old soup can to catch the metal. Make sure it's clean and preheat it with a torch for a few minutes just before casting to make sure it is COMPLETELY dry, then bury it in DRY sand almost to the rim. Pack the sand tight. The easiest way to do this is to tape paper over the mouth of the can to keep the sand out and after you bury the can shake your flask (the container with the sand in it) to force the sand to settle. Then top it off.

All that said, as George Wilson alludes to, I don't know if you could attain enough heat with a open flame and an open ladle to achieve a molten state. Those eyelets are probably yellow brass, which is has a higher melt point and is much trickier than the red brass that valves are made from. Also, the fact that they are small with a lot of surface area in ratio to the mass means that they will be A LOT of loss due to dross and burn off.

Unless you want to do it, just to do it, you're probably not going to get much of anything to make it worth your time and effort. If you want a billet of brass to turn you'd be better off buying one.

[Charles Wiggins]

When I was 15, I worked part time in a Plumbing Supply Store. Occasionally I would work with one of the plumbers as a helper. One job was in a basement having a dry concrete floor and the plumber ask me to get the lead furnace and heat up some lead for a cast iron joint he was going to caulk. I set the led furnace on the concrete floor, pumped it up and proceeded to heat up a full crucible of lead. I also put the cast iron ladle on the concrete floor near thee furnace.


When the lead in the crucible had melted it had some dross covering it and I decided to skim it off with the ladle. Big mistake. As soon as the ladle touched the molten lead, there was an explosion that entirely emptied the crucible of molten lead. Some lead covered my grease laden overalls, some splattered on my face, and some got on the plumber and the lady of the house who was just coming down the basement step to see how we were doing.


Fortunately, none of us were seriously hurt, but the plumber was visibly shaken as he said “ I should have told you to put the ladle on top of the furnace to drive off any moisture before dipping it into the molten lead.” I didn’t know any better.


I was not aware of this problem - after all the ladle was dry and it was laying an a dry concrete floor - how could it have any moisture in it. Besides, how could a little invisible moisture cause such an explosion.


It did and I learned a valuable lesson that day. Ever since then, I’ve occasionally wanted to make my own brass and aluminum castings but this memory always resurfaces and makes me think twice about doing so. Molten metal is nothing to fool around with if you don’t have the knowledge and proper safety equipment .


I hope this story helps someone.

Don

I was a sculpture major in college and have done a lot of casting. One time we were pouring aluminum (~800ºF) and we had some left over to pour out into the ingot tray. We have preheated the tray as we had many other times but there was a little bit of moisture in one corner of the tray that did not get chased off and when we poured the ingot we had an explosion. Some of it bounced off the ceiling and showered down on us. I was OK but my partner was balding and got 2nd degree burns on his scalp. The worst part is you can't just drop what you're doing. The metal has to be poured. The instructor took his end and we finished the pour.

We were lucky we were wearing fire jackets. A lot of times in the summer when the newer students weren't around if we were just doing aluminum and not bronze we'd forego the jackets because it would be hotter to wear them than not. With bronze we always had to wear them regardless of the ambient temp because the crucible was too hot to be that close to without protection.

[george wilson]

I might add that melting small pieces of brass is not so easy: The small pieces probably will not melt together because of oxidation on their surfaces. It is difficult to remelt chips for the same reason. I'd recommend adding a liberal amount of borax flux to the crucible before you even start to heat it up. The borax will melt all over the brass pieces,and allow them to remain clean of oxidation,and melt together. The borax will float on top and can be skimmed off before pouring the brass. At least,a hole can be scraped into the flux at the spout,and the brass can be allowed to pour out. Scrape the melted flux out of your crucible just after the pour,or it will turn to hard glass.The professionals at the Geddy Foundry refused a 10# bag of small brass chips I offered them,saying they were too hard to melt.

However,hot flux has a disadvantage: It MAY eat a hole into graphite crucibles.Some types certainly will. I'm not sure about Borax as I never had to use it myself.If so your expensive crucible will last 3 or 4 times before it has a big hole in it.

It has been many years since I did casting,and I did not try melting chips or small,thin things like eyelets. I refined silver using laundry washing soda,and it did a good job after repeated melts,but it ate a hole in my crucible. The silver was in the form of black powder from a photo lab. It was full of chemical impurities which the washing soda did absorb on every melt until the silver was pure. After messing around with it,and having 19# of it,I sent the rest to Hoover and Strong for refining the rest. The crucible cost $40.00. They send back pure silver casting grain. What I did not like was they would not take money. They kept some of the silver,which they took at scrap value(about half price). I'd have preferred to pay money.

You can buy brass flux on Ebay.

[Shawn Pixley]

Yes I would recomend UV protection there. It probably doesn't need to be quite as dark as if you are doing forge welding. I have safety glasses with UV protection. I also have a full safety visor with UV Protection. Your local welding supply place will be able to help here.

The brake drum forges are quite a good way to start. Do you buy or make your charcoal? Given the nearness of my neighbors, I use a propane forge with three burners. I am sure that the charcoal forge might be a step too far here.

[Shawn Pixley]

I was a sculpture major in college and have done a lot of casting. One time we were pouring aluminum (~800ºF) and we had some left over to pour out into the ingot tray. We have preheated the tray as we had many other times but there was a little bit of moisture in one corner of the tray that did not get chased off and when we poured the ingot we had an explosion. Some of it bounced off the ceiling and showered down on us. I was OK but my partner was balding and got 2nd degree burns on his scalp. The worst part is you can't just drop what you're doing. The metal has to be poured. The instructor took his end and we finished the pour.

We were lucky we were wearing fire jackets. A lot of times in the summer when the newer students weren't around if we were just doing aluminum and not bronze we'd forego the jackets because it would be hotter to wear them than not. With bronze we always had to wear them regardless of the ambient temp because the crucible was too hot to be that close to without protection.

Raining molten aluminum - yikes! If I a casting anything of size I wear my jeans under leather welding chaps and a jacket under my leather apron. We always had a large bucket of water available for you to put you foot or feet in if a spark or metal landed on (or in) your shoe. I used to forge wearing boots. It is remarkable how sparks find their way into your boot.

[Shawn Pixley]

However,hot flux has a disadvantage: It MAY eat a hole into graphite crucibles.Some types certainly will. I'm not sure about Borax as I never had to use it myself.If so your expensive crucible will last 3 or 4 times before it has a big hole in it.

It has been many years since I did casting,and I did not try melting chips or small,thin things like eyelets. I refined silver using laundry washing soda,and it did a good job after repeated melts,but it ate a hole in my crucible.

You can buy brass flux on Ebay.

I just bake out 20 Mule team Borax for forging flux. For fine metals (bronze, silver, gold) I use a good jewelor's flux. I will only go up 20-30% reclaimed material when casting. The balance is virgin casting shot.

With ceramic crucibles, the flux doesn't eat it as fast. George, I have never used a graphite crucible. I thought they were primarily used for metal refining? Good for you in the silver reclaimation! I agree they should have done it for money. Sounds just like the salmon canning "deals" out there.

[george wilson]

They used graphite at the Geddy Foundry. I haven't used anything else. There are small little ceramic crucibles for gold,and large,lined steel pouring ladles for iron and steel,but I never did work that large.

I would just use the 20 mule team Borax myself. But,I sometimes hesitate to recommend things I do to others. I would tend to play it safe with them and tell them to buy brass flux.

Ever been close to a 19th. C. borax wagon? I was in Death Valley JUST after we left Alaska in 1957(what a miserable place that was after being used to cool weather!!) Those enormous wagons had tires over 12" wide,and several feet in diameter. Loaded with borax,they must have wanted to sink into the desert sand pretty bad! Artifacts sitting in the desert lasted many years. The water tasted of borax until we crossed the Mississippi river. Even the soft drinks were full of it. Pepsis were bottled in Phoenix. We were used to good,pure cold water in Alaska.

[Steve Voigt]

Yes I would recomend UV protection there. It probably doesn't need to be quite as dark as if you are doing forge welding. I have safety glasses with UV protection. I also have a full safety visor with UV Protection. Your local welding supply place will be able to help here.

The brake drum forges are quite a good way to start. Do you buy or make your charcoal? Given the nearness of my neighbors, I use a propane forge with three burners. I am sure that the charcoal forge might be a step too far here.

Thanks Shawn, I'll dig up some UV lenses.
I just buy hard lump charcoal. Everything I've read says it should be fine as long as you don't use briquets. I'm using pretty minimal quantities, just doing plane irons and chisels, so cost isn't a big issue.
The charcoal burns very cleanly. I was surprised. It doesn't make much more of a mess than barbecuing.
Here's the homemade forge, in case anyone is interested:

photo-130.jpg photo-129.jpg

[Moses Yoder]

After careful consideration I have decided not to do this myself, but just to take the brass in for recycling. This is the reason why America will eventually fail; modern people value their life more than exploration. The thread obviously is not wasted; there is a lot of good info, and I learned a lot from it. When we made our own lead sinkers we used to run around in bare feet melting lead and pouring it into molds, no safety glasses (we didn't know what safety glasses were) and we are all still alive to talk about it except for my dad, and the lead casting had nothing to do with his death. Nowadays I would have to buy $6250 worth of safety equipment and take out special insurance and have any helpers sign a waiver before casting lead. No wonder I can't sell the eyelets.

[Dan Hintz]

When we made our own lead sinkers we used to run around in bare feet melting lead and pouring it into molds, no safety glasses (we didn't know what safety glasses were) and we are all still alive to talk about it.

This is the reason why America will eventually fail; modern people value their life more than exploration.

If you want to blame the eventual failure of America on anything (and I don't believe this is it), it sounds like luck and ignorance about safety are more appropriate scapegoats.

Nowadays I would have to buy $6250 worth of safety equipment and take out special insurance and have any helpers sign a waiver before casting lead. No wonder I can't sell the eyelets.

As has been said, this likely has nothing to do with why you can't sell the eyelets. The more likely reason is, "It's just easier to buy new!", as already suggested.

If you're truly interested in learning how to do this, then stop blowing it out of proportion and find someone to teach you (community colleges are a good place to start looking, especially ones with art-oriented programs). We're merely trying to prevent you from doing something highly dangerous out of ignorance... learn the right way to do it first, say goodbye to the ignorance, and have fun making custom stuff.

[Pat Barry]

When we made our own lead sinkers we used to run around in bare feet melting lead and pouring it into molds, no safety glasses (we didn't know what safety glasses were)

LOL - making lead sinkers are NOTHING like pouring molten brass. Give it a whirl though. What can go wrong?