Aluminum Foundry

stuartblack said:

Dont melt Aluminium in a steel crucible the Aluminium eats it, there are two groups on face book devoted to metal casting. Any questions you have, will have been answered before. Graphite crucibles are cheep.

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I dropped my account on the book of faces years ago. I'm hoping to find melting and casting ideas on metal working forums. Like this one or the others I belong to.

nel2lar said:

Rndmann9
The question of melting all your chips is a very good one. What I do when I gather up the chips I place them in a cut open soda or pop can, then I bend over the edges and crush the can down as much as I can. When I melt my other metal and the crucible is molten I will put the can of chips in and hold down until melt is started. I have a lot of chip melt under my belt and it is something that works and the best way to get the biggest bang for what you are doing.
Nelson

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Thats a good idea. It’s amazing the amount of swarf vs the resulting ingut. Swarf takes up a lot of space....

It’s addictive. I’ve been pacing around trying to figure out what I want to make next myself.

Well ToneyM safty first and if you can see whats happening through a molten liquid . But I have other uses for steel and for $25 for a #10 graphite crucible off Evil bay, cheep safty. There are a few youtube videos of steel letting go with aluminum in them. Luckily the ones I've seen no one got seriously injured. Melting aluminium in steel also creates a new alloy, so new crucibles for led, and castiorn dont mix theme for the same reason.

CFLBob said:

Although I've never had a builtin pool, one of my first jobs was working maintenance in a condo with big pools. Pool shock was like the liquid chlorine we dumped in to chlorinate the pool, only supposed to be way more concentrated. Looking around on Google before I saw what looked like some sort of crystals or powder that gets dumped into the water. Do you use the liquid or solid?

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Please, please, don't ever put water or an aqueous solution into molten aluminium. Many years ago I worked for Comalco and they had pictures of the results of just half a cup of water being inserted into the melt of a furnace. It showed an estimated 10 tons of aluminium around the front of the furnace, with the unfortunate furnaceman being somewhere underneath it all. Not only do you have the water, instantly turned to steam, with around 1600 times the volume of the water, but then it reacts with the molten aluminium, and is broken down into an aluminium oxide and hydrogen. All this releases a huge amount of energy, and it would not make for a good day in the shed if you try it.
While I have not tried casting myself yet, it is my understanding that the best raw materials to use, are old castings like alloy wheels. They are made from alloys specifically made for casting, while swarf will most likely be from alloys like 6061, which are often used for their machinability. I am presently camping in the Outback of Australia, and don't have any of my references with me but from memory the casting alloys are from the 2000snds and 7000nds series, but IIRC the 7000series has some zinc rich alloys included too. I seem to remember hearing that cylinder heads for overhead cam engines that have had the camshaft running directly in the head, that is without any bearing inserts, use one of the zinc rich alloys of the 7000 series. The same may apply to transmission, gearbox and other major vehicle castings, not sure if that is good or bad, some knowledgable person may chime in with the good oil.

I have found that a discarded pressure bladder tank from a well water system works very well for a furnace surround. Use a cardboard tube from Home Depot as the inner and fill the void with furnace cement.

I started casting in the 90's and have melted everything from aluminium to bronze and many alloys in between. I have read my share of so called bad effects from water and wet concrete. I have never tested fate but it is not as dangerous as most play it up to be. Molten metal is the biggest danger because if it gets on you, you are in trouble. Follow the safety rules and do not do anything that you do not feel comfortable with. WORK SAFE.
Nelson

nel2lar said:

I started casting in the 90's and have melted everything from aluminium to bronze and many alloys in between. I have read my share of so called bad effects from water and wet concrete. I have never tested fate but it is not as dangerous as most play it up to be. Molten metal is the biggest danger because if it gets on you, you are in trouble. Follow the safety rules and do not do anything that you do not feel comfortable with. WORK SAFE.
Nelson

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I agree that it is the molten metal that is the problem. However even a small amount of water, such as a damp drossing tool or de-gassing cup is enough to create a shower of molten aluminum droplets - plays havoc with the hairstyle.

Over the last 40 years I have always placed my moulds on a 1" dry sand bed and would never pour on concrete. I was taught how to play safely with aluminium over a 10 hour course with a professional foundryman turned lecturer and have always followed his advice and have been fortunate enough to play safely with molten aluminium for many years with no accidents, even when working with classes of fourteen year olds.

Enjoy working safely and live long and prosper.

Terry

Rndmann9,

Next you can create your own rifle receiver!
Way to go!

Done a bunch of aluminum, made my own sand muller, used a freon can for furnace lined with fireclay/sand refractory, An 8" piece of 4" steel pipe with plate welded on the end makes a good crucible. i found it works fine just burning small wood chunks with a squirrel cage blower run off a vairac to get speed control, run light enough blast to not throw charcoal out. A vehicle heater blower would work with it's speed control, run on a battery or battery charger. I also built a 55 gallon drum cupola to do cast iron but haven't gotten around to trying it out, (intend to use home made hardwood charcoal in it) was planning to cast parts for medium size steam engines, but when one old steam engine of about 15 hp showed up on ebay for an affordable price I grabbed it and the manufacture of them when on hold for awhile. Take it up later when I find some time to spare. Right now I'm building a home hydroelectric power plant using inverse water wheel. Once that's scaled up to full income level and a few greenhouses running off it, maybe I'll have time to dedicate to the foundry and manufacture of custom designed steam engines for personal use in tractors and trucks like I always dreamed of doing.

Reuben
Sounds like you have a plan.
Keep us up on your progress.
It all sounds good.
Nelson

This is what happens to steel crucibles when melting aluminium. Granted its a can its a steel can. Its not a question of if but when. Graphite crucibles are cheep. Imagine the burns from that aluminium

Stuart
That is one of the best videos on why not to use cheap containers like cans. When I started in the 90's I could get about 3 burns out of a can but the metal and the thickness is not what it was then. If you choose a metal can this is exactly what will happen. Very well done.
Nelson

I agree that using a steel can as a crucible is a stupid idea (I only ever did it a couple of times) but a heavy-walled steel pipe would not fail in such a catastrophic fashion. There would be warning signs, seepage into the furnace, visible alloy on the outside of the crucible, etc. long before the bottom or side just drops out. Graphite crucibles are far too expensive and difficult to source where I live so I'll stick with my steel, but of course I'll continue to inspect it as I use it.

It was interesting to see the dreaded 'concrete steam explosions' caught on camera too, and reminds me of my hot-dip galvanising days. Again, not the catastrophic event people envisage when they warn of such things. The droplets of alloy that land on you from such an event are certainly painful, and will leave a mark for a while at least, but aren't terribly serious. A good reminder to wear your safety gear though.

As a final 'war story', the company I worked for were trying to improve safety and bought each hot worker a supposedly "fire proof", button up, long-sleeved shirt. If the trial went well, we were to receive the matching long pants as well (both items were hideously expensive). They worked reasonably well for the most part, and did save us from quite a few of the 'normal' minor burns from spits and droplets (like you see in the video). However, when I had a major amount of liquid alloy ejected on to my chest, it dumped enough heat into the shirt to ignite the "fire proof" material and it went up in flames - and we could not beat it out. Ironically for safety reasons, a water supply was not kept close-by to the molten metal area, so my only option was to remove the shirt, still buttoned up, over the top of my head as it burned ferociously. After that experience, I went back to using my trusty leather apron and my hair grew back eventually.

Yeah K $25.50 for a 10 yep thats sooooooo expensive

I was looking around a foundry supply web site. They carry several types of additives for aluminum. Silicone among them..
Does anyone have info on the additives?
No information on what they do.
I was on another youtube channel, Myfordboy.
He uses a couple of additives/ fluxes, salt, and a de gasser. He turns out some decent looking castings
Myfordboy recommends not using cans or extruded alloy for casting.
I was thinking there might be an additive that converts such scrap for good cast material.
Dennis

I melt anything I can find excepting cans. I've thrown 6061T6 tooling plate scraps, extruded door, window frames, busted auto transmissions and auto rims in the mix. Always degas with pool shock and I have had nothing but good luck.
Jack

Yeah casts and extruded are different alloys so in the mix you dont have what you start with. Also another reason not to use steel crucibles. Despite people saying its not much. You I nobody knows what the new alloys are. The easist way is can you machine extruded Aluminium in its natrual state easily ? Can you with cast ? One is not really the other is yes. In the end its really up to you. Mag wheels are a good but try a sample piece first some have magnesium. Apareantly it can burn through the crucible and furnace. Dont know if thats true.

I made one with a 15 gallon-ish metal trashcan with ceramic blanket and the black pipe/welding tip torch like the one from (the king of random)
In my attempt to melt copper, I had to double up on the torches and used added a canned fan mounted to a manifold plenum to get forced air in both torches.
It worked great on Aluminum with one burner, but 2 burners melts it so much faster.
Copper takes forever and I lose nearly 1/2 of it as dross, but it does melt it eventually.

I have a friend with a small machine shop and I get aluminum turnings, and the coolant residue on the turnings causes a HUGE amount of dross!
For aluminum, go to the auto parts salvage yard and get castings made out of aluminum, like transmission parts.
Taking damaged parts to the counter is great for talking them down on the price, or go to a metal recycle shop as they have it sorted by type.

The video is great for showing us that a bean can with no more than a few thou wall section is unsuitable for use as a crucible for melting aluminium. In fact it's barely good enough to melt lead in.
It does not make a steel crucible dangerous or unusable providing it is of sufficient wall section.