Mixing Molten Metals. What Could Go Wrong?? 

It’s cool that so many people are commenting and trying to predict the results. I’m reading all the comments, but there are too many for me to reply to all of them. And it seems I’m not the only one who didn’t predict the crappy alloy problem. 🤦‍♂️ Appreciate all the interaction. Have a great weekend everybody!

First thing I thought was: Never do experiments with molten metal in shorts! 😂

I’m guessing if you’re pouring it in together and making a 5050 mix it will probably not be that great. I tried this years ago in the ingot broke when I dropped it , I really hope you have found a solution🤞🏻.....

There are no failures in projects like this, just varying levels of success! Thank you.

Mix the heated metals prior to pouring them. Once you have a nice hard Cu-Al cast, apply a thin coat of one or the other pure metal to your casting by dipping your casting into the molten metal. Make sure the molten metal is as liquidy as possible to produce the thinnest layer as possible. Once cooled down, grind smooth for a textured dual metal surface look. Just an idea. :) Happy creating!

One of the most underrated channels out there. Thank you for posting videos like this - you learned, and we all learned.

See 'Welding Metallurgy' by Linnert. It has been my go to source for 30+ years. The book could be considered a bible to anyone considering a life in metals. It explains why stainless is stainless and which aluminiums are weldable. It helped me to weld aluminium to steel. The copper section is extensive and describes the various alloying agents.

have you thought about pouring the aluminum out onto a metal table top, letting it cool, then pouring the copper next to it? The heat of the copper should melt only a little bit of the aluminum and I think you would get the effect you wanted.

As someone that makes beer for a living, I deal the specific gravity all the time. I have to assume there is going to be a oil and water kind of separation effect.

"what am i doing today?" "double fisting crucibles of molten metal." "what should I wear?" "shorts, yah, definitely shorts."

My first thought was "this might explode", my second thought was... "naw, he know what he's doin'". ;D

All I could think when trying to predict was "2 crucibles at once?! Craziest damn thing I ever heard of." Lol, and also "they probably won't mix evenly before freezing". You made that cannon though, so I gave it a chance. Glad I did. Fun video. I love my homemade aluminum bronze axe, keep trying! Keep in mind, even 13% is enough Al to get a glass-brittle alloy. From my own research and experience making and casting Al-bronze, one good way to get it evenly mixed is to alloy it in one crucible; add the Al after the Cu melts and mix the ingredients with a smooth up and down motion with something like a skim tool rather than a stirring motion, taking care not to agitate the surface of the melt. Mind you, I do this with the crucible still in my propane furnace with the burner running. An electric furnace would mean pulling it out and having to hurry more before things cool down too much. But if you are able to rig up a way to pour 2 crucibles simultaneously, I'm sure you can figure that out too. Then pour ingots to remelt when you go to pour your actual molds; that should help with getting the ingredients even more fully mixed together. Good luck!

This is why sheetmetal is made by rolling out ingots rather than casting it into thin sections like this.

A thought...try doing a low temp pour in areas with aluminum. allow to cool, then pour in the copper after. the copper will reheat and melt the aluminum in very limited areas.

I stumbled upon this video and found it very interesting. Along with the fact that I learned something that I have never even thought about. Thanks for the information.

Those crucible holders are pretty cool TBH. Thanks for sharing your videos, even when they don't quite go to plan. Have a good one man. 😎

Copper and aluminum have different rates of thermal expansion, so even if you do get some interesting swirls going on, I think they'll separate and crack as they cool. Also, they have different densities, so the aluminum may end up floating on top of the copper. Is there a reason you didn't just heat the aluminum up in the same furnace to 2000F? Will that cause excessive oxidation?

5:20 The abrupt temperature increase to the aluminum... I don't know... can aluminum burn?

Awesome! Every time we learn something new it’s absolutely a success!

I did this a long time ago just with some copper wire and an aluminum can melted together in a steel can. Ended up with the same stuff you sanded to a shine. Eventually this intuition helped me design something really cool with other slightly different metals.

Had no idea what would happen but very impressed with your control when pouring cheers from UK

Your crucible holders are awesome!

I'm glad that mix didn't pop and fling molten metal on you, since who knows what sorts of stresses develop between the materials during pouring and cooling. Stay safe! I like your videos.

Thanks for showing us your mistakes and being an honest bloke! As for when it comes to metallurgy, it is more complex then most people think. In order for the bonding between two metals to happen, you sometimes need to use a several different pre-treatments, add fluxes into the molten metal.. Use vaccum, pressurize the alloy whilst its mixing.. etc. There is a lot that goes into doing it the best way, depending what type of alloy you are making. I would try lookup some of the fluxes you might want to use in order to make the metals more suseptible to bonding.. And the correct temperature can also be critical to make the results good. Its like when you do a soldering with a soldering iron and solderingwire... if you do the solder correctly.. you have clean surfaces and little contaminants.. You have enough flux to help with bonding.. you have the correct amount of heat, to not overheat, and not too low heat, so it won't properly liquify. But warming the solderingwire for too long.. also overcooks the alloy, and removes the flux... and the solder becomes brittle.. matt, and voids starts appearing.. less bonding and so on.. If you compare that to this experiment, it would indicate that there are contaminants.. possibly the oily stuff in the green sand. maybe the temperature is too high, or too low.. Maybe you need a flux. Maybe you need 0.2% of a nickel, to use as a catalyst. Maybe the copper needs to be preheated and heated for 30 minutes extra... versus the aluminium poured immidiately after smelting. Perhaps making the alloy first, and then casting it, could solve some of the problem as well. But in any case, i think with the right flux(fluxes) even that would get u further. There are fluxes that removes contaminants.. Fluxes that allows higher or lower smelting temperatures.. fluxes that changes viscosity Fluxes that increases bonding potential. etc.

This is definitely cool, I would love to see more things like this! My undergraduate research was on trying to fuse YMnO3 and HoMnO3 using a focal point of light to heat the material to 2400 C after pressurizing it into a semi-stable but brittle (previously preheated powder) cylinder. By using the intense light to heat a single point to melting (but not so much it drips), we were able to slowly move the focal point up the length of the cylinder and allow physics to create the most energy effective crystal direction of growth. This allowed us to make large single crystalline samples for neutron diffraction, but it's so cool to think how else melting techniques and molding techniques could be done!

The cool looking result your after with two different types of metal and a transition zone between them, reminds me of explosion welding.

MAN, I love that T-Shirt I'm a steel fitter welder fabricator I've trained/worked with soooo many know-everything hardheads I've seen it all!!!

I've been interested in using aluminum bronze for pommels and other knife and sword furniture. Thanks for experimenting for me!

Cool experiment and a good, practical way to learn something. I'd like to see you melt the proper aluminum bronze and cast something from it.

I just love the execution of this experiment, especially compared to the many other youtubers who have done the same thing. I just hate it when a youtuber is like "lets mix random metals, aluminum, brass and copper!" and the first thing I think is "but copper is already IN brass, instead why don't you substitute brass for pure zinc." I'm glad you didn't make the same error as so many other youtubers, and yes, there are other people who have mixed a bunch of metals on youtube.

Those crucible holders are awesome innovations! Patent them!

Cool experiment

i had to pause on your 'this is not a drill' shirt because i was wheezing. i love shirts like that. big dad energy

I've no clue what's about to happen but I'm giddy with anticipation.

I've seen many folks with the proper attitude toward trying something new like this, and not getting the hoped-for result. You didn't fail! You succeeded in a different direction (as long as you were able to learn new things from it.) I loved the polish on the actual aluminum bronze section. 90% copper, 10% aluminum? I'd bet there's a good metallurgy/chemistry reason behind that particular combination.

I enjoy your apparently inexhaustible ideas that you also implement!

You might be able to get an interesting effect from filling your mold with copper pellets or turnings, then pouring aluminum in. The outer layer of the mold will be wetted by the aluminum so you would need to cut into the model to get color changes.

One thing that I would love to see is if you tried basically this same process, but measured out the ratios of copper to aluminum in advance. You said it yourself that due to its high surface tension its difficult to control how much aluminum you pour into the mold. But if you are simply emptying both crucibles, I don't see this being an issue. Of course, you would still end up with a sub-optimal alloy due to the amount left behind and the variations throughout the pour, but it could potentially be strong enough for an art piece like you had said.

My meager input: You want layers like this, you'll need to pour copper over solid aluminum that's been treated in some manner to avoid passivating, but that manner has to be compatible with the process (i.e. acid dip straight into paraffin would preserve the surface but isn't going to behave well when molten copper is poured over it in a tight mold). Solution's likely to zincate copper shapes (lye bath electroplating with zinc). The zinc should absorb into the copper, hopefully, well enough to avoid bubbles, and the aluminum surface would be devoid of oxide so copper should bond well. Then you can turn the piece and have your layers well bonded with minimal alloying taking place.

Extremely coool crucible crutch holders or “crutchibles”!

I can't believe I just sat here and watched you do that ! Rush into town, go to the library, grab first book you see on metallurgy, read the pictures and look at the words, eat yout cereal with a fork, and stop using the Internet for information. ;)

One technique you could try would be to cast the copper first then cool it, clean it, brush it shiny then apply aluminum to the outside of the copper casting, and cover it with slip and reheat the copper to the melting point of aluminum. This would cause alloying of various amounts according to various factors such as thickness on the aluminum, oxygen , fluxes and depth of heating. I've made aluminum copper alloys before just playing with a torch and the hardness and brittle nature is surprising. The stuff almost looks crystalline when hit with a hammer. Perhaps some of the crystalline alloy could be 'painted' onto a copper vase after it is ground to a powder and mixed with a flux?

Interrupted pours generally result in a weak casting even if your staying with the same metal. The exception is adding a bit more to an open riser/feeder or spru as it shrinks. And there are better ways of handling that too. Was fun just the same.

At the 5:20 mark, my guess was that either the temperature difference would keep the metal from binding properly (possibly having some minor combustion in the mold) or that there's another binding element missing which could cause the metal to split apart after solidifying After watching the rest of the video, the solidified outcome is about what I thought it would look like, but the reason for that outcome was not what I was thinking. I've only had a little bit of experience with metallurgy through welding, I wasn't expecting the metal to bind as much as it did, and kinda thought there would be more of a pattern with highly brittle weak points where the metal overlapped, it's neat to see multiple alloys form from just two materials (even if the vast majority of them formed a brittle mass of unusable junk metal) the fact there was a portion of it (even a small one) which came out close to the desired alloy is cool.

Because of the different viscosities in the 2 metals, pouring them separately is going to mean they will not mix and, most likely become separate pieces when they solidify. Mixing them in a liquid state would ensure a better bond, but having one next to the other would cause a difference in their structure as they cooled at different rates. You might get a slight mixing between the 2, but it won't be enough for them to bond properly. It'd be interesting if you were to pour them in and do a single swirl to the point where the 2 metals weren't uniformly mixed but where they come into contact with each other may have mixed sufficiently to provide a bond.

Maybe... the hot copper will make the alluminum boil? Splashing molten metal of over the place... Glad I was wrong and you were safe!

Ok just got to having buffed it! Exactly as I suspected. Gas bubbles....its like a cold joint in a concrete foundation pour when a jackwagon doesn't calculate properly and had to order a second truck for the following day.

Difference on density (Cu 8 g/cm3, Al 2.7 g.cm3) will make the liquid Al try to work its way up through the liquid Cu - so there may not be nice layering but instead some kind of a solidified slurry of the two metals, which might separate from each other and cause the whole block to crumble if the metals contract differently on solidifying. It works for damask because the solid layers are very similar in physical properties (density, thermal expansion, etc).

Melt up a batch of the strong aliminum-bronze and cast the vase with that! Maybe throw some 1/4 in steel ball bearings in while it's heating to see what that does to the surface, knowing it won't ever be hot enough to melt the steel. Or better yet, fabricate a frame from 1/8" steel rod (or whatever diameter is suitable), and then cast a layer, let it cool, switch metals, cast a layer, let it cool... This was the steel framework is what will keep the copper and aluminum from otherwise breaking at the cold-joint. Still, was a great show, but then again, I think nearly all of your videos are pretty great! Namaste

As a metallurgist here are my predictions. The layer pour method will only produce layers if each layer is allowed to solidify to some degree. Without the pervious layer being solidified the two metals will just mix together forming Al Bronze. The simultaneous pour will just lead to the formation of Al bronze no stripes of different metals will likely be present. Edit: I always seem to forget about the density differences in liquid metals, when arc melting samples we melt them several times to make sure the elements are homogenously distributed. I would honestly try this again with AL and Cu but let each layer solidify before pouring the next. By allowing layers to solidify you avoid creating brittle intermetallic compositions from the uncontrolled pouring of the metals.

I love how your t-shirt works on about 4 different levels. 😅

Love the T-shirt!

Pour layers of copper and silver to make your vase. Give ample time for molten metal to freeze between layers. Do not expect the vase to hold water when complete.

Stopped at 5:20 - My prediction: The temperature difference between these two fluids is huge: 600f. Think about what happens when you pour boiling water on ice... a difference of less than 400F. There is a violent reaction as the temperatures equalize rapidly. I think what will happen is similar... there will be a lot of bubbling and popping and spraying.. and general danger. I think in the end you will end up with some blobs of copper/aluminum, though. Either way, you're alive to upload the video, so it couldn't have been that bad. Edit: Oh, interesting! Thanks for doing these experiments. Fun to watch. I have never done any casting but I enjoy watching it happen.

🤣🤣🤣🤣 I just dropped my phone @ shit-bronze!!!!! 🤣🤣🤣👍 Ok.... going back to finish the rest of the video now.

Would be interested in seeing it poured into something like a cement mixer, that way they are actively being mixed, though might just coat the mixer. But active mixing could let you pour in the copper and the pour in the aluminum while the copper is still hot. Then once alloyed you could repeat and cast into something useful

Aluminum has a fairly small molten state, go past it and it crystalizes, go further and it vaporizes. I've worked in an aluminum casting plant, aluminum is caustic when molten and is VERY temperature sensitive (if you are wanting to keep the integrity of the aluminum). I worked back in mold repair and we would have to soak the cast steel forms in high temp caustic soda to dissolve the majority of the aluminum, wash them off, sand blast the rest of the aluminum off, put them in a tempering oven before we could weld the pitting that the aluminum caused. There was always a little aluminum left in those pits, and it the second you hit it with a TIG torch, the aluminum would get real bright (like a little sun) then fade to dull red right before it vaporized while the steel around it heated up and I could fill those damn pits.

With a copper zinc mix, do be a bit careful with the vapours. The copper is hot enough to make the zinc boil and catch fire - the fumes give you a nasty fever for a few days.

They mixed a good bit more than I had expected.

Spray form. Spray them at the same time. Let the molten metals leak out a small hole in the bottom of the crucible then force them with compressed gas toward the mold or make a billet to be machined. Adjust distance from the part for each metal. There won't be a lovely Damascus look to it though.

Aluminum bronze alloy sounds like a great solid bushing material.

I predict that the copper will lead the aluminum in heat and force it to remelt which, depending on moisture content may lead to explosive results if it gets trapped. I see now that it does remelt slightly. It seems that a metering process is needed, perhaps a preheated crucible to mix the molten materials together and then pour the concoction into the mold. If I was going for a copper / aluminum look, I would perhaps rough up the surface of the mold in some way, pour the copper, then put in a second mold with smooth walls and pour the aluminum. Finishing with a belt sander down to the copper / aluminum layer. Thanks for the interesting video

Maybe you could prepare two crucibles of copper, then drop the right amount of aluminum into one to get aluminum bronze in it, and then pour these. That should avoid the brittle alloy and still could create some patterns.

This is going to explode Edit: That was less dramatic than I expected. I thought the huge temperature difference would lead to extremely fast cooling.

Australian $1 & $2 coins are aluminium (note the correct spelling lol) bronze. They are very, very slow to wear out which is exactly what’s needed for the two most used coins.

not as bad as i expected, that aluminum brass stock may be interesting if it could be pattern welded to a nice carbon steel.

You learn something from everything you do...especially the oopsies. Fun fact: I have the same shirt...and my kid says "Yeah, I know...it's a hammer...duh"

the most extreme 'edward 40 hands' challenge ever!

Years ago i was pouring small bronze sculptors and making my own bronze using copper (90%) and tin (10%) by weight. I made a gas fires foundry . I melted the copper first and then added the tin in the molten copper using the same crucible. then I added crushed coke cola bottle glass the glass melted to form a gas seal on the molten bronze, a cold metal rod poked into the bronze would remove the glass and a hand full of borax was add to the bronze as a flux before pouring

Love the experimentation! There is an Al/Cu alloy called 'Duraluminium '. I'm not sure what the ratio is, but the alloy looks like aluminium, so I'm guessing Aluminium is the dominant ingredient. It's used for it's stiffness properties. Like engine mounting plates. Edit: Wikipedia has the mix as 91-95% aluminium, 3.8-4.9% copper, 1.2-1.8% magnesium, 0.3-0.9% manganese,

So, here is my thought, it would be fairly difficult to do, but if you just melted copper, and some how suspended a number of small pieces of aluminum inside the mold (not molten, probably help to get the mold fairly warm tho) then added your molten copper, the heat of the copper, would melt the aluminum in the spots where it is resting. I don't have much experience casting metal but I'm sure there is a wax or something you could lodge inside the mold to hold the aluminum in place that would simply be burned away upon adding the copper? this way you can use your vase molds, and get your copper aluminum mixed patterns. I bet you'll find that the little bits of aluminum will spread farther throughout the mold than you might think (big splotches of silver color despite fairly small pieces of aluminum) and you'll end up with a stronger alloy closer to your aluminum bronze!

Just from observing the lifting of two crucibles I'm thinking about how it's bad to have your hands all tied up, in case of a trip/slip or fall. There's also a lack of ppe which doesn't bode well... But obviously you lived so I hope whatever happened wasn't too bad.

There are several problems. The first is that the aluminum isn’t pure. They’re alloys. There’s likely magnesium in there, which normally is strong, but is brittle when heated like that. Secondly, heating the molds would allow the aluminum to be more liquid rather than hardening almost instantly when poured in such a thin layer. I’ve made aluminum bronze, but not what you’re trying to do.

It might be interesting to try this as a three metal pour and have three different feed holes going into the same form. You would need an assistant foundry worker or two, now is a perfect time to start apprenticing people, and see how that turned out. With a poor with brass and bronze work? You're saying something about color contrast and if it's big enough between the two maybe that would work. By the way, new subscriber!

You should do some molten dirty pours. Just let it splash out on a cement slab next to each other, on top of each other, etc. they do it with copper alone here in Miami AZ copper country. It is big.

Nordic gold - 89% copper, 5% aluminium, 5% zinc and 1% tin. Molten zinc is a pisser for its flammability. It better goes in as zinc copper brass. The tough alloy takes a high polish and is very showy. Copper aluminide, almost ceramic, is grown after casting the mixed alloy. The Al-sparse alloy cast piece is reheated to grow a matrix of crossed micro needles.

i worked one summer at East Alcoa aluminum factory... it's quite amazing how much electricity it takes to smelt aluminum

That did exactly what I though it would. Make stuff with Aluminum Bronze mix. It is lighter weight than typical bronze. It is also more corrosion resistant than most types of bronze. It you want stuff more like damascus you really can not do that with molten metal. Gravity of the fluids will always end up doing that.

Finding the 2 thousand year old recipe for Corinthian Bronze/Brass would be a thing. Once more highly valued than any metals. Use was on a massive scale. They knew how to work with it. So much has been lost to history.

Electrician/electrical engineer. My guess is the difference in temperature would cause a reaction like poring boiling oil and water together. The aluminum would heat to a hotter temperature causing popping and splatter the still liquid metal. But given their weight and that the temperature that copper melts at would not cause the aluminum to turn to a gas the distance on the splatter should not be more than a few feet.

I'm guessing a lot of sparks flying, but no reasoning behind it...it would just be fun to watch.

Really weird observation, but with the melting temps different, what about casting an aluminum part, clean it up and mount it in the sand mold, much like a chill or a plug, and then pour copper around it, that might allow you basically "stencil" an aluminum image on a copper background.

I was expecting a nasty reaction because of heat differential in the mold. An extremely weak alloy is a marked improvement on what I was thinking was going to happen.

I melted left over copper and brass together and i got half and half copper on top not a distinct line between them .good fun.

Your issue here to me seems to be the mould is stone cold and solidifies whatever you pour into it, when it strikes the mould. Either preheat them a lot(maybe not possible with sand), or make a steel mould(Coquille casting style?), to avoid the shock cooling/solidifying before it's had a chance to mix/interact

I can honestly say I have no idea what will happen. I don't think there will be any aluminum bronze but there might be some cool patterns between the two. I also think they might delaminate like they won't really stick together but will break apart once they are cooled. Edit: Dang! I didn't even think about the weight of the metals and the copper sinking, also that little piece that you sanded looks sweet!

I predict it will make fancy Slag

should do a multi brass pour. Like Nichol brass and then copper brass alloy. Should come out looking like a tiger stripe pattern if you do it right.

I have no idea if these two metals can be smithed (heated and hammered, forged?) like iron and steel can, but I would have liked to see him try on some of the better chips that actually mixed. It was definitely a cool experiment. Also, Dude! Mind your safety more!

Aluminum brass, at least in my metallurgy game copper and aluminum make aluminum brass. In there we use it to cast moulds for other metal castings. Here I would imagine you will get seperation as the metals are mixed after they start cooling.

My prediction? Probably some form of reaction at the oxide layer that makes this somewhat dangerous to perform outside of an inert atmosphere. Although even neglecting that, a striping of dissimilar metals from a homogenous melt into the mold usually will result in interesting grain boundaries that range from cutting diamonds like butter to being polymer putties. So, whatever results will probably not blend well and just crack apart during cooling.

Idea 1: Boundry layer messes up pour. The lower temperature of molten aluminium cools copper too quick and forms granules that clogs the channels. Idea 2: Some kind of exothermic chemical reaction. Cooper and aluminium will form a battery in electrolites. Maybe they do it really quick when in liquid state. Might not be a problem when you melt them, as only a small amount is liquid at while they are mixing? Sucks, neither hit.

You're lucky you didn't get a violent thermite reaction between copper oxides and molten aluminum.

Only 2 minutes into it, but you can heat the aluminum all the way up to 4,400 F before it starts to boil, so the aluminum does not have to be at only 1,200 F, trying to freeze the copper...Nice one-hand crucible holders!

There is an alloy of Al Cu and Fe that is used for high pressure parts in aviation, if I recall.

With the ceramic casting skeletons, try Nordic gold. Absolutely beautiful stuff and relatively simple recipe to create. Food for thought...

Dual wield crucibles. Nice.

You can cast Al over Cu if you wanted to a more interesting pattern. If you filled the mold with copper granules/scrap/whathaveyou, then heat the mold to something like 550 or 600 C (Al melts at 660), and then pour the Al over the top you should be able to maintain much better segregation. The melting point difference is more severe with Cu Al, but my wedding band has something similar with gold scrap cast into a silver ring. Tis very pretty. If you have any ferric chloride kicking around I would be curious to see a quick etch of the piece you sanded up. The grain structure in there is going to be pretty neat, although there may not be anything big enough to see with the naked eye.

Stopping at 5:20 to give my prediction... Since both metals are at different temperatures, there's a chance it might go volatile, with the aluminum being overheated to compensate for the copper's high temperature. It'll be like a fudge ripple of metals; they'll swirl together but not form a true alloy.

Its going to flash or explode or do something crazy. The reason why I think that is because the temperatures are so far apart. You probably need to start with the hottest material and then slowly add the other.