# Aluminum Foundry



## Rndmann9 (Jun 24, 2018)

So after accumulating a lot of aluminum swarf I built myself a foundry.  Turns out casting is pretty fun.  Anyone else jump down this rabbit hole?  Started as an empty helium tank. Some ceramic insulation blanket 1” a little bit of refractory cement and a burner made out of black iron pipe and a propane nozzle made from a copper welding tip.  Works great.  Green sand is the hard part.  Easy to make.  Hard to get moister just right expecially when it’s hot out side since it drys very quickly.  I purchased some petrobond which is fantastic and produces nice surface finishes but it’s pricy.  I’ll build on this thread as I gain experience.


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## machinejack (Jun 24, 2018)

Been down the same rabbit hole myself. You could change my name to Rndmann9. I only use my greensand for big project. Got 40 Lbs of Petrobond and love it. You really need a muller if you want to keep using it, as the sand next to the casting gets baked. Go look at Mr. Pete 222 on You Tube. Lyle has some very informative videos you can watch. Wood working skills come in to play as you will need patterns.


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## Rndmann9 (Jul 12, 2018)

Done a couple projects now. I might have to put the kids to work for mulling. I just mix it good before I use it.


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## Rndmann9 (Jul 12, 2018)

Here is a couple of the foundry.


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## Rndmann9 (Jul 12, 2018)

The little pin was for an old safe that was missing one and here is the finished rifle saddle.


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## vederstein (Jul 13, 2018)

I started casting last winter.

Build log of my first self cast engine here: https://www.homemodelenginemachinis...n-column-steam-engine-cast-double-size.27224/

I have a lot to still learn though.  Note that I've been making my patterns with a 3d printer.

...Ved.


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## Rndmann9 (Jul 13, 2018)

That’s my next step.  I don’t have a 3D printer but I built a CNC mill and a printer is basicly the same principle so that also might be on the horizon.  So far I’ve just made wood molds except for the hinge pin since I had an original.


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## cephas (Jul 13, 2018)

Rndmann9 said:


> Started as an empty helium tank.



Hey, Rndmann9, good write up!   I had an empty R-22 bulk tank that I had used for remote compressed air tank years and years.  Then I did a thoughtless giving it away and have been regretting that since.  
---cephas


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## Rndmann9 (Jul 13, 2018)

Took me a while to decide on a tank but I’ve had this one a while and finally used up the helium so figured it was as good as any.  Ive seen propane tanks used.  Just make sure it’s purged of any gas before you cut it or it could be a rather enlightening experience lol. Most expensive part is the ceramic wool insulation.   I’ve seen people use aluminum beer kegs and cheap metal trash cans.  since the insulation doesn’t let the metal get too hot.  Clay flower pots will work too.


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## Rndmann9 (Jul 13, 2018)

vederstein said:


> I started casting last winter.
> 
> Build log of my first self cast engine here: https://www.homemodelenginemachinis...n-column-steam-engine-cast-double-size.27224/
> 
> ...


Thanks for the link.  Been reading through it.  I’m actually looking forward to winter. It’s some hot work right now with it being around 90f outside.  What did you model in fusion?   I use inventor personally but I do 3D drawings for a living so I’ve got several different options software wise.


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## vederstein (Jul 13, 2018)

Rndmann9 said:


> Thanks for the link.  Been reading through it.  I’m actually looking forward to winter. It’s some hot work right now with it being around 90f outside.  What did you model in fusion?   I use inventor personally but I do 3D drawings for a living so I’ve got several different options software wise.



I have access to a seat of Inventor.  In the past I've use Intergraph EMS, Solid Edge, Solidworks, now Inventor at work.  Except for EMS, which is totally antiquated, each package has its advantages and disadvantages.  Personally I perfer Solidworks, but I no longer has access to it.

... Ved.


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## Rndmann9 (Jul 14, 2018)

I use revit most of the time for work.  Occasionally cad but I pretty much stopped using cad 10years ago and went to revit. Inventor for me took over for cad. I work for an electrical contractor.  When I got inventor hsm a couple years ago I knew it was time to turn the mill into a Cnc mill.  

So my wife is a teacher and challenged me to caste her an apple for her desk.  Challenge accepted.  Still need to clean it up but an interesting shape to cast.


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## CFLBob (Jul 14, 2018)

This is well timed.  I have two five gallon buckets filled with aluminum chips and other swarf and I've been thinking about making a foundry to melt it down for other uses.   I've seen other guys use a cast iron muffin tin to pour the melted metal into, just to reduce space.  

I should probably clean it up.  I'm sure that besides being contaminated with some WD-40 or other oils, there's probably some steel swarf in there, too.  Just because I've cut some and it might end up in the chip pile, too.  I'm sure the oil would just burn off, but I guess the steel/whatever would either form dross on the top and get skimmed off, or maybe settle to the bottom.


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## Rndmann9 (Jul 14, 2018)

Oil will burn off. The steel will do as you said and either sink or float up as dross.  Keep in mind the muffins are just a convenient way to store it so further processing can be done down the road.  Mines kind of mixed too.  If you have a strong magnet you can get most of the steel to separate.  Still got plenty to go  not to mention aluminum cans.  One thing to note is the swarf due to its surface area creates a lot of dross.  If you can melt some solid first then dunk the swarf or cans it works better and doesn’t oxidize as quick   Also if you can press the swarf to make them more dense.  I’ve put it down a tube and used a dowl to make little “bricks”


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## Rndmann9 (Jul 14, 2018)

The steel is easy to spot in the melt though since it will glow bright orange and not melt.


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## Cogsy (Jul 15, 2018)

Rndmann9 said:


> The steel is easy to spot in the melt though since it will glow bright orange and not melt.


Interestingly (to me anyway) the aluminium also glows red but is so reflective it's not easy to tell unless you're in low light or using a video camera on the right setting. I didn't realise you'd be able to see the steel in the ali but next melt I'll give it a go just for interest. Thanks for the tip.


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## Rndmann9 (Jul 15, 2018)

Cogsy said:


> Interestingly (to me anyway) the aluminium also glows red but is so reflective it's not easy to tell unless you're in low light or using a video camera on the right setting. I didn't realise you'd be able to see the steel in the ali but next melt I'll give it a go just for interest. Thanks for the tip.


Yeah I only notice the aluminum if I'm pouring at night.  In normal daylight it looks like quicksilver.  It's kind of neat at night because it's a dull orange but shiny at the same time.  The graphite crucible is usually brighter than the aluminum. The steel however is pretty bright even in daylight since it's almost yellow orange in comparison.  It's also noticeably more ridged when pulling off dross.  Aluminum that hasn't quite liquified has a crumbly cake like texture.


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## Rndmann9 (Jul 15, 2018)

If I melt some soon I'll try to snap a picture with the steel in the mix.  I obviously try to avoid it but sometimes a small spiral of steel gets through.


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## Rndmann9 (Jul 15, 2018)

If I melt some soon I'll try to snap a picture with the steel in the mix.  I obviously try to avoid it but sometimes a small spiral of steel gets through.


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## SmithDoor (Jul 15, 2018)

Rndmann9 said:


> Oil will burn off. The steel will do as you said and either sink or float up as dross.  Keep in mind the muffins are just a convenient way to store it so further processing can be done down the road.  Mines kind of mixed too.  If you have a strong magnet you can get most of the steel to separate.  Still got plenty to go  not to mention aluminum cans.  One thing to note is the swarf due to its surface area creates a lot of dross.  If you can melt some solid first then dunk the swarf or cans it works better and doesn’t oxidize as quick   Also if you can press the swarf to make them more dense.  I’ve put it down a tube and used a dowl to make little “bricks”  View attachment 102755



In California you would wait for fogy day on chips

Dave


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## trently (Jul 15, 2018)

Hi all, Another source of good scrap to melt is an auto repair shop as there is a lot of aluminum parts that gets replaced and thrown out. the best is pistons but suspension components are good to


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## MRA (Jul 16, 2018)

You're really going for it, melting swarf!  I seem to collect more ali scrap than I need, partly I suppose due to where I work - I've used a lot of extrusions (doors / window frames) which people say are not the best, but I've had OK results.  I have some pistons and a load of what is apparently cast alloy, saved up for something that 'matters'.  You know how it is.  

A recycler I know collects beer cans from an alcoholic neighbour, the painted walls of which he cuts off (!!) to save for roof shingles for a projected shed.  We had a go yesterday at compressing 'ends' in his press, with the idea of melting with less surface area / oxidation / dross.  He has high hundreds, perhaps thousands.  I don't know how I feel about a shed which is a monument to the tenacity of someone else's liver.


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## Rndmann9 (Jul 17, 2018)

Lol. When I was in college one of the local homeless but industrious guys used to come by my fraternity house and collect all the beer cans in a grocery cart...one day he showed up in a brand new f150 truck.  I often wondered how much money we literally tossed and he gave me the assurance at that moment it was plenty.  The swarf is just a reserve. I've got a fair amount of scrap so when I'm done with a pour and don't quite have enough for muffins I'll toss a couple bricks of swarf in while it's hot and make a couple muffins for the next one.  If you leave enough melt to dunk them they don't create a ton of dross. More than I'd like but better than throwing out all that aluminum potential.


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## Wizard69 (Jul 17, 2018)

Wow, nice castings for a first effort!   Starting with swarf doesnt make the process easy.  

By the way most of my casting experience is from working in a zinc die cast foundry just out of high school.  Metal contamination can raise hell with your resultant alloys, id suggest keeping a close eye on what goes in the pot.  

In a die cast zinc plant steel falling into a pot {pot metal}of zinc is a bad thing.   The way the engineer explained it to me is that the steel in contact with the molten zinc and cast iron creates an acid that eats through the cast iron.   Im not going to debate if it is an acid per say but you can clearly see how the steel eats through the cast iron when the pot is drained.  I know this pulls the thread off track but i was amazed as a young guy to see how this happened.  I found it especially odd because cast iron and steel are so closely related.


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## Cogsy (Jul 17, 2018)

Wizard69 said:


> In a die cast zinc plant steel falling into a pot {pot metal}of zinc is a bad thing.   The way the engineer explained it to me is that the steel in contact with the molten zinc and cast iron creates an acid that eats through the cast iron.   Im not going to debate if it is an acid per say but you can clearly see how the steel eats through the cast iron when the pot is drained.  I know this pulls the thread off track but i was amazed as a young guy to see how this happened.  I found it especially odd because cast iron and steel are so closely related.


 Long ago I worked as a hot-dip galvaniser, which is primarily molten zinc with some small amounts of nickel, lead and aluminium. Our pot (called a kettle in galvanising) was steel and large amounts of steel and cast iron was lost to the bottom of the kettle to be fished out at the next dross removal shift (oh how I hated those shifts but we only did it every few months). Interestingly, we were told that copper in the kettle was a very bad thing and if we tossed in a 1 or 2 cent coin (which were copper back then) they would eat their way through the bottom of the kettle. Sounds like much the same as you were told but obviously different metals - and it's very likely that there was no truth to either story. Some metals don't play well (Gallium and Aluminium for instance) but steel/zinc/copper/cast iron work well together. I think those 'old guys' were pulling our collective legs and we were gullible enough to believe them.


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## CFLBob (Jul 17, 2018)

Do you ever put some sort of flux in while you're melting the aluminum swarf?  I've melted silver and we always throw in some borax.


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## Rndmann9 (Jul 17, 2018)

CFLBob said:


> Do you ever put some sort of flux in while you're melting the aluminum swarf?  I've melted silver and we always throw in some borax.


Light salt ( potassium chloride & sodium chloride. Degass the aluminum with calcium carbonate (washing powder) not to be confused with calcium bicarbonate (baking powder).


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## Rndmann9 (Jul 18, 2018)

Correction to earlier statement. Sodium Carbonate not Calcium


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## CFLBob (Jul 18, 2018)

Thanks.  I'm looking for plans for a foundry I can build.  Lots to choose from.  

I already have an acetylene/air torch.


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## SmithDoor (Jul 18, 2018)

I used propane and or fuel oil #2 aka diesil fuel
The old type furnace unit works great just flip of switch and it is running 



CFLBob said:


> Thanks.  I'm looking for plans for a foundry I can build.  Lots to choose from.
> 
> I already have an acetylene/air torch.


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## machinejack (Jul 18, 2018)

For non porous castings in aluminum I have always used pool shock for a flux/degasser . A reil type propane burner in a 12" piece of pipe lined with 1" of kaowool. In a home made sch 80 pipe crucible. Been doing this for a few years. I started out using a green sand made with bentonite clay but have since graduated to PetroBond. Now 66 years old "I'm retired from the clock but not from life".


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## CFLBob (Jul 19, 2018)

Isn't pool shock liquid chlorine?  I think I've heard of some sort of powder, but the only pool shock I've seen used was liquid chlorine solution.


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## machinejack (Jul 19, 2018)

I only know that before I started using it I had porosity in my castings. I read somewhere about using pool shock to get the hydrogen gas out. I use a forked rod and roll a little bit of the shock in aluminum foil  and as soon as I take the melt out of the furnace I plung the rod to the bottom of the crucible slowly stir the pool shock in. It bubbles for a few seconds then I skim off the dross. Don't know the chemistry but it works for me. Stay up wind of use a respirator as chlorine gas is produced.


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## CFLBob (Jul 19, 2018)

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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## machinejack (Jul 19, 2018)

You need the powder form.  Ace Hardware sells it HTH brand. Most big box stores carry it under different names.


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## nel2lar (Jul 20, 2018)

Rndmann9 said:


> Oil will burn off. The steel will do as you said and either sink or float up as dross.  Ke”  View attachment 102755



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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## Wizard69 (Jul 20, 2018)

The issue with the loss steel was very interesting to me as you could actially see how a dropped bolt or whatever would eat though the pot when it was drained.    In a couple of cases you could see the thread imprint in the cast iron.   

Honestly when I left that plant after about 2 and a half years of working there it was the happiest day of my life.   Conditions where bad and most of the people employed there where not the types you could trust with being safe.     I lost track of how many times I drove into the place to find out that an ambulance had been called yet again to take somebody to the hospital.    Now I work at a place where they go overboard with safety, thank fully the only time an ambulance gets called is for someone having a heart attack.    Not that that is  a good thing mind you but none of them have been job related.




Cogsy said:


> Long ago I worked as a hot-dip galvaniser, which is primarily molten zinc with some small amounts of nickel, lead and aluminium. Our pot (called a kettle in galvanising) was steel and large amounts of steel and cast iron was lost to the bottom of the kettle to be fished out at the next dross removal shift (oh how I hated those shifts but we only did it every few months). Interestingly, we were told that copper in the kettle was a very bad thing and if we tossed in a 1 or 2 cent coin (which were copper back then) they would eat their way through the bottom of the kettle. Sounds like much the same as you were told but obviously different metals - and it's very likely that there was no truth to either story. Some metals don't play well (Gallium and Aluminium for instance) but steel/zinc/copper/cast iron work well together. I think those 'old guys' were pulling our collective legs and we were gullible enough to believe them.


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## Cogsy (Jul 20, 2018)

Wizard69 said:


> Honestly when I left that plant after about 2 and a half years of working there it was the happiest day of my life.   Conditions where bad and most of the people employed there where not the types you could trust with being safe.     I lost track of how many times I drove into the place to find out that an ambulance had been called yet again to take somebody to the hospital.


Another similarity of the jobs, when I began working at the galvanisers I was replacing a 20 year old guy sent to the hospital with 3rd degree burns to 75% of his body (never found out if he survived) yet being young and stupid I didn't think too much about it. While I was there for only around a year and a half, there were many accidents and I had to (literally) run for my life on 2 occasions. I got out with only 1 serious burn and a smashed foot but many close calls. While I was employed we only had 1 fatality at the plant but I don't know how it wasn't more. It's so much nicer doing what I do now...


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## stuartblack (Jul 21, 2018)

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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## TonyM (Jul 21, 2018)

stuartblack said:


> Dont melt Aluminium in a steel crucible the Aluminium eats it. Graphite crucibles are cheep.


Although what you say is true, the reaction with steel is so slow that it is not overly important if the crucible has a decent wall section.


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## CFLBob (Jul 21, 2018)

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.



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.


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## Rndmann9 (Jul 21, 2018)

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


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


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## Rndmann9 (Jul 21, 2018)

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


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## stuartblack (Jul 22, 2018)

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.


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## Ropetangler (Jul 22, 2018)

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?


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.


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## Darthtrader (Jul 23, 2018)

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.


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## nel2lar (Jul 23, 2018)

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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## terryd (Jul 24, 2018)

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



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


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## AdvenJack (Jul 25, 2018)

Rndmann9,

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


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## reubenT (Jul 25, 2018)

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.


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## nel2lar (Jul 26, 2018)

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


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## stuartblack (Aug 4, 2018)

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


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## nel2lar (Aug 4, 2018)

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


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## Cogsy (Aug 4, 2018)

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.


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## stuartblack (Aug 5, 2018)

Yeah K $25.50 for a 10 yep thats sooooooo expensive


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## dkwflight (Aug 5, 2018)

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


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## machinejack (Aug 5, 2018)

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


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## stuartblack (Aug 5, 2018)

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.


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## Archangel (Aug 5, 2018)

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.


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## TonyM (Aug 6, 2018)

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.


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## Archangel (Aug 6, 2018)

A graphite crucible is the only way to go!


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## Cogsy (Aug 6, 2018)

stuartblack said:


> Yeah K $25.50 for a 10 yep thats sooooooo expensive


That's a good find - they seem to have come down in price since I last looked, though I would like a bit bigger than that. Had a (really) quick search myself and only turned up the ~$80 ones I was expecting but the cheaper units must be there somewhere. But yes, to me, that is quite expensive for something I can make for free when I'm on a very limited income - it might be peanuts to you, but it's certainly more than I can afford.

This is the sort of thing my search turned up:


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## Archangel (Aug 6, 2018)

Please post how you cast a graphite crucible for free!
My #8 has been working well so far but every time I clean it before starting the next melt, there is a tiny bit of interior worn off and someday it will add up to buying a new one.


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## stuartblack (Aug 6, 2018)

There is this but I cant find one ingredient

In the bar with 10 kg tap the down arrow theres a twelve at the bottom


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## stuartblack (Aug 6, 2018)

IMG_1215



__ stuartblack
__ Aug 6, 2018






16kg I could be there all day with the listings theres thousands


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## Cogsy (Aug 7, 2018)

stuartblack said:


> IMG_1215
> 
> 
> 
> ...


 Yeh, I know. I couldn't find the cheap one you found but plenty at $80 or so. With the dodgy listing practices/search manipulation eBay allows its sellers to do, finding the best price is getting difficult.

@Archangel - I can't cast graphite crucibles at all, let alone for free. I meant I can weld up some heavy steel pipe for free.


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## reubenT (Aug 7, 2018)

50/50 mix of kaolin clay and alumina, dampened to stiff clay consistency, formed into a cup by whatever means works,  on a wheel or packing into a form,  or just free hand but that makes an uneven cup.      then dried and fired.   Supposed to make a good crucible.    I just use my 3/8" thick steel can because my castings are not critical as to exact alloy, and I use whatever aluminum I have including cans and extruded,   just making hubs and pulleys.  But copper or brass requires the ceramic crucible,  being their melting temp is too close to steel.   By the time the brass is melted the steel will be like soft butter and fall through.  Backyard metal casting is a good resource for info http://www.alloyavenue.com/vb/forum.php


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## stuartblack (Aug 8, 2018)

Hey Cogsy The $25.50 was in Australia but came from hongkong . I assume your in the US the 16kg one.(I envy you guys cant find that big on Au ebay ) is US price and suprised me cos the US dollar is higher than ours. I would think would be somthing like $10. I wonder where the crucibles are sourced cos if there $25 here the seller is making a profit even with free postage. They must pay $2.00. Hmmm Ill just see if china has evil bay pitty i cant read chineese ,And see if i can find a price


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## Ghosty (Aug 8, 2018)

The cheapest 16kg one I found was $70, from HK
https://www.ebay.com.au/itm/1-2-3-4-6-8-10-12-16KG-Graphite-Furnace-Casting-Foundry-Crucible-Melting-Tool/322615886013?hash=item4b1d67c0bd:m:mrdiLrVRXWNsdwUR7Yl041g&var=511611358026&_sacat=0&_nkw=16kg+graphite+crucible&_from=R40&rt=nc&LH_TitleDesc=0

I have a 8kg one, as that is the largest the forge I have access to can take.

Cheers


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## stuartblack (Aug 8, 2018)

Whoa man thats bad I found a 2kg for between $26 - 30 Thats no help to any body. I wonder why there so cheep here.


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## stuartblack (Aug 8, 2018)

Thats so weird Ghosty I dont understand why the prices are so different.


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## Ghosty (Aug 8, 2018)

stuartblack said:


> Thats so weird Ghosty I dont understand why the prices are so different.



Don't know, it just pays to spend a little time looking as you can save a lot of $$$$$. I do this as well when looking for tools and supplies as well, i'm on a limited income so i have to watch where the $$$$ go.

Cheers
Andrew


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## stuartblack (Aug 8, 2018)

I did find this but guess what sold out 16 kg Thats on US Ebay. Thats what I wanted with the spout, not fair, you guys get all the good stuff . Well i now know to searh deeper


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## Cogsy (Aug 9, 2018)

stuartblack said:


> Hey Cogsy The $25.50 was in Australia but came from hongkong . I assume your in the US


It seems to have dropped off my profile but I'm an Aussie too, though I'm in Perth so we often get stung for extra postage on stuff to get across the Nullarbor. I think I want a 10 or 12 kg one but I've only ever found them at $80 ish so haven't bothered. I'll have more of a look on ebay and see what I can dig up.


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## stuartblack (Aug 9, 2018)

put this item number in evil bays search bar     152445427080
Thats a 12 I bought the 10 from this crowd be interesting to see if its the same price over WA


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## Cogsy (Aug 9, 2018)

stuartblack said:


> put this item number in evil bays search bar     152445427080
> Thats a 12 I bought the 10 from this crowd be interesting to see if its the same price over WA


Very good pricing but as feared - they won't ship to WA at all. Their shipping excludes half the country by the looks of it :
*"Posting to: Australia
 Excludes: Northern Territory, Perth Metro, Adelaide Metro, QLD Far North, WA Regional, SA Regional, Tasmania, WA Remote"*
Oh well, someday I'll get one. Let us know what the quality is like when you get yours.


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## stuartblack (Aug 10, 2018)

Man thats shitfull Australia wide delivery execpt .
 It looks like there photo funny enough like exactly. I wont be heating it up for a while though.


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