I've watched a few other of this man's videos concerning the degassing of aluminum. In each of them he seems to do everything in his power to prevent the process from working. He tends to use aluminum that appears to be just barely molten as opposed to performing the processes in the furnace at temperature. In this case, it appears that he sprinkles the salt onto the dross layer and doesn't even attempt to mix it into the actual aluminum. When he does feign an attempt at incorporating the salt, he seems to be folding the salt into the dross and then scooping it out. Also, he seems to be using the coarsest salt crystals he can find. A "fairer" procedure would be to keep the crucible in the furnace, encapsulate the salt in a foil packet and plunge it to the bottom of the crucible with a degassing plunger. Also, finely grinding the salt would probably make the reaction more likely to occur. I would also have liked to have seen him add some of the molten salt into some molten aluminum. If the process/reaction had any chance of actually working that seems like it would have been the most likely scenario.
For a short while I worked at an aluminum extrusion plant where they dealt with melting tons of aluminum at a time. Degassing was carried out in the gas fired furnace while still being heated, not after the melt was allowed to cool outside the furnace.
I don't know about degassing, but Paul's Garage used Morton Lite Salt to help separate the aluminum from the slag and it seemed to work great for that purpose.
According to the chemistry buffs, the chloride salt reacts with the aluminium, producing aluminium chloride. Aluminium chloride is a gas at these temperatures (with no smell). The gas forms small bubbles. Hydrogen in the aluminium diffuses readily into these small bubbles (low partial pressure) and is carried away. No chlorine is released. You won't ever break up a chloride salt of an alkali metal by heat alone. They're about the most stable chemical bond you can have.
To produce Aluminuim Chloride aluminium has to reduce sodium chloride to sodium and chlorine gas and then what happens to the sodium metal that is leftover? It is so light that it floats in molten aluminium. As you said alkali chloride salts do not breakdown with heat alone so how can aluminium chloride be produced if it will not breakdown. You need to find some chemistry buffs that know what they are talking about
I powdered The Pink salt and mixed it 50/50 with anhydrous Borax and saw a difference, but i put it back in my furnace after adding for about 5 min. There was gas coming out the puddle was moving and i didn't remove the heat till the surface turned black, i think theres magnesium in the pink salt as well as NaCl
NaCl is used for salt glazing of ceramics. It is added at temperatures well above its melting point (801 degrees C) by tossing packages of it into the firebox. The salt melts, vaporizes and flows through the setting. As some of the salt condenses on the pots the sodium reacts with the clay to form a glaze and the chlorine goes up the flue ( very nasty stuff as it produces hydrochloric acid in combination with moisture in the air). In short. the temperature is critical to any reaction.
You have to use a bell plunger and it works great been using it for years both Potassium chloride and Sodium or a mix. It will bubble through the melt and pull out all dissolved hydrogen. Just a note Hydrogen start to be absorbed once the melt is all turn into liquid. The longer your heat the melt the more violent the bubbles will be. Do it this way and pull a sample and put under vacuum and it will have zero porosity when cut.
I use powdered/fine silicon carbide in foil packet to the bottom, mix, then lite salt in a foil packet pushed to the bottom, let melt and then mix in de-dross. Saw chlorine solids being used as well for more advanced de-gassing but thats pretty iffy on the safety side as it makes some seriouslly nasty gasses.
When chlorine is used to degass aluminium, it is actually reacting and producing aluminium chloride. It still works because AlCl₃ has a low boiling point of only 180°C. I'm guessing that the reason the book says you can use NaCl to produce chlorine for aluminium degassing, is because someone confused it with hexachloroethane, which _is_ actually used for aluminium degassing. Hexachloroethane thermally decomposes into tetrachloroethane (dry cleaning fluid) and chlorine gas. It is a white crystalline solid at room temperature. Since sodium chloride does get used as a flux, I could see how someone might confuse the two.
I personally have had the lite salt burn a very bright flame, scared the crap out of me I thought I might have had a magnesium fire.. But I always test my scrap before melting
the salt is used as a flux, not a degasser. I usually melt it and break it up as a two part reason, first, it creates a eutectic that lowers the melting temperature of the salt, and two, it drives off the moisture so that when you break it up, keep it in airtight containers till your ready to use. Salt is quite hygroscopic, so you want to keep it out of contact with the moisture in the air. I use granulated pool shock wrapped in aluminum foil, and it breaks down into chlorine gas, and bubbles through the molten aluminium. I know it produces a good amount of chlorine gas because it's come up under my face shield a few times and got me in the face.
yea, for that stuff, I wouldnt take with a grain of salt, but his gating techniques are interesting. I think most people that that cast with aluminium know the salt eutectic as a flux anyhow, not as a degasser. Ive seen plenty of stuff used as degassers, but the best is just to learn to control the burner to control the atmosphere rather than messing with degassers.
you state that the salt forms a eutectic, a eutectic of what? the aluminum and the sodium? do you have any data on this. in regard to the pool shock wrapped in foil, the majority of the bubbles developed are from the expanding entrapped gas in the wrapped up granules rather than the chlorine gas being developed. This process is introducing more gas and moisture into the molten metal than what it can remove. the large bubbles developed just does not have the surface area to degas.
I have been in large aluminum factory. They had huge melting operations pour big slabs and roll it to make thin aluminum sheets. The used large amounts of salt and you could smell the chlorine in the air. It rusted everything around the furnaces. So I believe you are incorrect based off what I have seen in a large setup.
BCS (among others) seems to offer a degassing flux for aluminum, but I have no clue what’s in it. Perhaps the MSDS might list major reactive components, if not their proportions, but my limited Google searching has not turned those up either.
Use a chloride salt of a metal less reactive than aluminum, such as zinc chloride. You can also just use dry air or nitrogen bubbled in from the bottom that will wash the dissolved hydrogen out of the aluminum. The hydrogen in the aluminum is formed by aluminum reacting with water vapor in the air above the molten metal. The aluminum reacts with the water, pulling off the oxygen forming aluminum oxide and the remaining hydrogen can dissolve in the metal. Chlorides or chlorine work because the hydrogen will form hydrogen chloride gas with the dissolved hydrogen.It is an acrid smell, but doesn't smell like chlorine.
Right, this makes no sense. You can get salt white-hot before it breaks down. It's not going to break down into chlorine due to heat alone. Maybe if it reacted with something, aluminum or aluminum oxide, but from what I recall of chemistry, that doesn't make sense.
Indeed it's complete bollocks, and whoever wrote that paragraph didn't know any better. To remove hydrogen from molten aluminium, for small batches, it is common practice to use tablets of a hexachloroethane - organic chlorine is relatively easy to strip from the molecule, ionic chlorine from sodium chloride definitely is not (industrially aluminium is degassed by bubbling argon through the molten metal). By the way, aluminium chloride does in fact give off hydrogen chloride when exposed to water or moist air (zinc chloride doesn't, as I wrongly said before); I'm not quite sure if it'd give off chlorine in molten aluminium, it sounds plausible though.
I agree. I think the book was wrong. I THINK that an electric current passed thru the molten metal would do better to dissolve aluminum oxide back to aluminum and free oxygen and hydrogen.
how is it supposed to degas if your just mixing it at the top, try putting it in some aluminium foil and holding it at the bottom. there are so many factors that cause bubbles, and one factor that will make a difference depending on where you live, I've never been to Australia, but where I live (which is the same place as myford boy) the UK has more moisture in the air which the aluminium absorbs and splits the oxygen and hydrogen and creates hydrogen gas. love your videos though, especially the cast iron ones.
In the book it says it will remove hydrogen as a flux but it will float on the top only. Salt will absorb moisture so if it is plunged to the bottom it will bubble.
You're right that NaCl or KCl solid salts won't work as everyone is using them. I think i've seen an older video of yours on the same topic. I believe part of the mythos of this ritual is based on a misunderstood fact though. NaCl/KCl solid solutions _are_ used as the basis for aluminum fluxes, but they must be in a solid solution before they'll melt at a low enough temperature to be effective. I also don't know how well the salt mixture does by itself. It may only serve as a mechanism of lowering the melting point of a more important component (in my case, CaF2) Page 131 of "Handbook of Aluminum' by Totten, MacKenzie shows a phase diagram of a NaCl-KCl-CaF2 aluminum flux. The melting point of the eutectic mixture is about 660C. I've made this flux by dissolving fluorite (CaF2) in molten salt mixture. The accuracy of making homemade flux this way is troublesome because absorbed moisture throws off the weights unless you roast the salt first. The flux I've described melts a bit higher than the aluminum flux BCS sells, but it performs the same. The foamy metallic dross will separate to a loose grey ashy material, and your metal loss rate is minimized. I even went and recovered a bunch of ingots out of my old dross bucket. I've tried other gimmicky household things, and they only made more metallic dross. I think most people don't really understand what to expect of a dross cleaning flux, so the remaining claims tend to be the ones that are the least easily disproven by eye at 240p (e.g. degassing performance). As far as degassing goes, i don't think it really does any good for that. If anything, you've just demonstrated my point about how much water is in salt stored in permeable containers. That moisture does anything but degas metal. Oh. Before anyone asks: NaCl-KCl mixture is roughly equimolar or ~4 parts NaCl / ~5 parts KCl by _DRY_ mass CaF2 should be about 5% by mass. Inaccuracies only result in a higher melting point. Large crystals of CaF2 won't melt simply, but it will slowly dissolve in the molten salt, so give it time. Alternatively, pottery materials suppliers sell CaF2 flour as a fluxing component for ceramics/glass/glazes. IIRC, Laguna lists it as "Fluorspar, Superfine'. Keep the ground flux in an airtight container.
you're welcome I should add: if the book isn't on google books anymore, a quick search for the paper "Solubility of CaF 2 in NaCl-KCl salt flux for Al-recycling and its effect on Al-loss" by Milke et. al should provide a superabundance of info on NaCl-KCl-CaF2 mixtures, phase diagrams and all that lovely jazz. Also, regarding degassing, Pyroflux P-40 is listed as a specialty flux for cover/drossing with mild degassing ability. This product is an unknown mixture of KCl-MgCl2. I haven't gone looking for info on KCl-MgCl2 binary solutions, but I imagine it's whatever ratio yields about a ~650C liquidus. Might be something to think about for any curiosity-motivated future experiments, but once we're talking about grinding/roasting/melting/mixing/casting/grinding a bunch of salts to make flux, the attractive simplicity of using ubiquitous products kind of evaporates. These fluxes aren't terribly expensive.
Dream Services International pls can I just add up sodium chloride and potassium chloride and mix it up with fluorspar and use as flux in scrap aluminum melting or must I heat up the sodium chloride and potassium chloride and fluospar to a molten state before using the composition as aluminum flux?
I am glad you clarified this. I have read several Ammen books and thought he was an authority of the foundry art. Just as you have dispelled many other myths in foundry work it just goes to show 'Proof of the pudding etc'. Looking forward to your next episode. :-)
Always been curious as to why some people pronounce Aluminum (Ah-loom-In-Um) as Aluminium (Al-ooo-men-ee-yum)? Lol hopefully this is understandable haha. Honestly though, there is no extra letter I in the last portion of the word so I'm curious as to how one would read it that way or even pronounce it as such?
You can use sodium carbonate, wearing a mask cause of some toxic emanations but for "home casting", degassing is like unecessary... just my point of view.
@@verdatum what determine the aluminun whether they overcooked or nor, is it the high temperayure or let them stay in molten temperature for a long time?
The melting point for NaCl is 801 °C so how could it go into a solute form if your Al is below that? If it could and there was H also dissolved in the Al then you could get HCl (hydrochloric acid once it dissolves into water) But what happens to the Na? It could form Na2O if it can rob some O from any oxides present, otherwise from the air on the surface of the melt. So it sounds like it is one of those things that only works under specific conditions, which the book does not define, and that is poor technical writing.
In my other comment, I describe a NaCl-KCl-CaF2 flux. The fact that eutectic solid mixtures like this have much lower melting points (660C) than any of their components and utilize additional fluxing agents (CaF2) leads me to think that this whole "dump salt in there" fad is just cargo cultish nonsense based on the misunderstanding of actual products. Then again, i'm just talking about drossing. Idk that it does anything for degassing, but the fact that it's hard to prove it doesn't degas (without material testing) means that's the claim that persists.
Mature Patriot he has addressed degassing in one of his vids. This man is a true master of casting. Need to sub to his channel it's one of the few that has no ads as I believe he has a true love of showing his art and sharing of his knowledge.
If that's pure sodium you have there, when not sealed it should be stored in oil. It will react very violently to water, even the moisture in the atmosphere could be enough to set it off. If you haven't seen it before, carefully and from a distance, drop a very small piece (match head size or less) into a pot of water and watch the reaction!
A friend gave me about 1/2 kg of Metallic Sodium, it was in a glass jar of Paraffin oil. I used to cut off a piece, throw it on the ground and hose it with a spray of water. The reaction was very violent, an explosion and ball of molten metal.
Chlorine gas has no odour, the smell you get in a swimming pool is the chlorine reacting with contaminants in the water, i.e. urine, sweat and oils from the swimmers. The reaction creates chloramines which is where the odour comes from.
Saltwater pools (fresh water with salt added--about 3000 pm; ocean is like 10x that) have a salt cell/generator electrode that the saltwater passes through. As saltwater passes through, electrolysis occurs, splitting the salt and water into hydrogen and hypochlorous acid (HOCl). I'm not sure if introducing electricity into a crucible would work! But Darren is correct: chlorine is odorless...public swimming pools have that "chlorine smell" but it is indeed chlorine reacting with sweat, urine, oils, etc. that produces the chloramines that can bug one's nose, eyes, and skin. Chloramines are formed when HOCl reacts with ammonia--a component of sweat, urine and body oils. Anyway, more than you wanted to know!
Terribly sorry chlorine has a strong pungent odour, I taught the chemistry of chlorine for more than 30 years. Chlorine is a yellowy-green dense gas with a choking smell. That is the opinion of the Royal Society of Chemistry! Or try ua-cam.com/video/BXCfBl4rmh0/v-deo.html I don't know where you get your "facts" from.
Yes Stephen I agree. Anyone who isn't just Regurgitating "Facts" KNOWS Chlorine does have an ODOR and If they had generated Chlorine Gas and SMELLED IT they would Never Forget that experience IF they Survived.
zippy, if you knew what you are talking about you would consider the displayed information more deeply. first of all the the salt did not melt nor decompose at the temperatures of molten aluminum. if the salt did not decompose to sodium and Chlorine then it would not react with any hydrogen or be able to degas the aluminum. all that happened with the salt was that the entrapped moisture was released - a very important point. Now for all those mistaken people that wrap the salt up in foil and submerge it in the molten aluminum there is a bigger problem. the massive air bubbles produced is not from the degassing of the aluminum but from the expanding gas that was trapped in the foil when it was wrapped. Looks good but makes the problem worse. next to make things even worse- the moisture that was in the salt is released deep within the molten aluminum and makes any entrapped hydrogen WORSE. So go suck, wrapping anything in foil and submerging it in the melt, makes the entrapped gases worse - the bubbles are the gasses you were trying to prevent entering.
I've watched a few other of this man's videos concerning the degassing of aluminum. In each of them he seems to do everything in his power to prevent the process from working. He tends to use aluminum that appears to be just barely molten as opposed to performing the processes in the furnace at temperature. In this case, it appears that he sprinkles the salt onto the dross layer and doesn't even attempt to mix it into the actual aluminum. When he does feign an attempt at incorporating the salt, he seems to be folding the salt into the dross and then scooping it out. Also, he seems to be using the coarsest salt crystals he can find. A "fairer" procedure would be to keep the crucible in the furnace, encapsulate the salt in a foil packet and plunge it to the bottom of the crucible with a degassing plunger. Also, finely grinding the salt would probably make the reaction more likely to occur. I would also have liked to have seen him add some of the molten salt into some molten aluminum. If the process/reaction had any chance of actually working that seems like it would have been the most likely scenario.
For a short while I worked at an aluminum extrusion plant where they dealt with melting tons of aluminum at a time. Degassing was carried out in the gas fired furnace while still being heated, not after the melt was allowed to cool outside the furnace.
What did they use for degassing? Did they use CO2 or some kind of solid fluxing compound?
I don't know about degassing, but Paul's Garage used Morton Lite Salt to help separate the aluminum from the slag and it seemed to work great for that purpose.
I was under the impression that flux should be pushed to the bottom of the molten aluminum with a specialized tool.
Yeah! But maybe the impurities are on top of the metal liquid.
I've never seen flux used where it wasn't mixed in thoroughly.
Whenever I've seen salt added to aluminium it was rolled up in a ball of foil and pushed to the bottom
According to the chemistry buffs, the chloride salt reacts with the aluminium, producing aluminium chloride. Aluminium chloride is a gas at these temperatures (with no smell). The gas forms small bubbles. Hydrogen in the aluminium diffuses readily into these small bubbles (low partial pressure) and is carried away.
No chlorine is released. You won't ever break up a chloride salt of an alkali metal by heat alone. They're about the most stable chemical bond you can have.
To produce Aluminuim Chloride aluminium has to reduce sodium chloride to sodium and chlorine gas and then what happens to the sodium metal that is leftover? It is so light that it floats in molten aluminium. As you said alkali chloride salts do not breakdown with heat alone so how can aluminium chloride be produced if it will not breakdown. You need to find some chemistry buffs that know what they are talking about
I powdered The Pink salt and mixed it 50/50 with anhydrous Borax and saw a difference, but i put it back in my furnace after adding for about 5 min. There was gas coming out the puddle was moving and i didn't remove the heat till the surface turned black, i think theres magnesium in the pink salt as well as NaCl
Maybe add a little pepper as well.
NaCl is used for salt glazing of ceramics. It is added at temperatures well above its melting point (801 degrees C) by tossing packages of it into the firebox. The salt melts, vaporizes and flows through the setting. As some of the salt condenses on the pots the sodium reacts with the clay to form a glaze and the chlorine goes up the flue ( very nasty stuff as it produces hydrochloric acid in combination with moisture in the air). In short. the temperature is critical to any reaction.
You have to use a bell plunger and it works great been using it for years both Potassium chloride and Sodium or a mix.
It will bubble through the melt and pull out all dissolved hydrogen. Just a note Hydrogen start to be absorbed once the melt is all turn into liquid. The longer your heat the melt the more violent the bubbles will be. Do it this way and pull a sample and put under vacuum and it will have zero porosity when cut.
hi sir, would you remind sharing your contact with me cuz i have some questions on behalf the flux and i will be thankful for you.
thanks
I use powdered/fine silicon carbide in foil packet to the bottom, mix, then lite salt in a foil packet pushed to the bottom, let melt and then mix in de-dross. Saw chlorine solids being used as well for more advanced de-gassing but thats pretty iffy on the safety side as it makes some seriouslly nasty gasses.
When chlorine is used to degass aluminium, it is actually reacting and producing aluminium chloride. It still works because AlCl₃ has a low boiling point of only 180°C.
I'm guessing that the reason the book says you can use NaCl to produce chlorine for aluminium degassing, is because someone confused it with hexachloroethane, which _is_ actually used for aluminium degassing. Hexachloroethane thermally decomposes into tetrachloroethane (dry cleaning fluid) and chlorine gas. It is a white crystalline solid at room temperature. Since sodium chloride does get used as a flux, I could see how someone might confuse the two.
It also makes the aluminum more fluid....table salt
I personally have had the lite salt burn a very bright flame, scared the crap out of me I thought I might have had a magnesium fire.. But I always test my scrap before melting
the salt is used as a flux, not a degasser. I usually melt it and break it up as a two part reason, first, it creates a eutectic that lowers the melting temperature of the salt, and two, it drives off the moisture so that when you break it up, keep it in airtight containers till your ready to use. Salt is quite hygroscopic, so you want to keep it out of contact with the moisture in the air. I use granulated pool shock wrapped in aluminum foil, and it breaks down into chlorine gas, and bubbles through the molten aluminium. I know it produces a good amount of chlorine gas because it's come up under my face shield a few times and got me in the face.
The book says sodium and potassium chloride will breakdown with heat to give chlorine gas.
yea, for that stuff, I wouldnt take with a grain of salt, but his gating techniques are interesting. I think most people that that cast with aluminium know the salt eutectic as a flux anyhow, not as a degasser. Ive seen plenty of stuff used as degassers, but the best is just to learn to control the burner to control the atmosphere rather than messing with degassers.
That is what i do.
you state that the salt forms a eutectic, a eutectic of what? the aluminum and the sodium? do you have any data on this.
in regard to the pool shock wrapped in foil, the majority of the bubbles developed are from the expanding entrapped gas in the wrapped up granules rather than the chlorine gas being developed. This process is introducing more gas and moisture into the molten metal than what it can remove. the large bubbles developed just does not have the surface area to degas.
What do you mean granulated pool shock...what is that? pls reply
I have been in large aluminum factory. They had huge melting operations pour big slabs and roll it to make thin aluminum sheets. The used large amounts of salt and you could smell the chlorine in the air. It rusted everything around the furnaces. So I believe you are incorrect based off what I have seen in a large setup.
BCS (among others) seems to offer a degassing flux for aluminum, but I have no clue what’s in it. Perhaps the MSDS might list major reactive components, if not their proportions, but my limited Google searching has not turned those up either.
Use a chloride salt of a metal less reactive than aluminum, such as zinc chloride. You can also just use dry air or nitrogen bubbled in from the bottom that will wash the dissolved hydrogen out of the aluminum. The hydrogen in the aluminum is formed by aluminum reacting with water vapor in the air above the molten metal. The aluminum reacts with the water, pulling off the oxygen forming aluminum oxide and the remaining hydrogen can dissolve in the metal. Chlorides or chlorine work because the hydrogen will form hydrogen chloride gas with the dissolved hydrogen.It is an acrid smell, but doesn't smell like chlorine.
Right, this makes no sense. You can get salt white-hot before it breaks down. It's not going to break down into chlorine due to heat alone. Maybe if it reacted with something, aluminum or aluminum oxide, but from what I recall of chemistry, that doesn't make sense.
In the book it said to use heat alone.
Indeed it's complete bollocks, and whoever wrote that paragraph didn't know any better.
To remove hydrogen from molten aluminium, for small batches, it is common practice to use tablets of a hexachloroethane - organic chlorine is relatively easy to strip from the molecule, ionic chlorine from sodium chloride definitely is not (industrially aluminium is degassed by bubbling argon through the molten metal).
By the way, aluminium chloride does in fact give off hydrogen chloride when exposed to water or moist air (zinc chloride doesn't, as I wrongly said before); I'm not quite sure if it'd give off chlorine in molten aluminium, it sounds plausible though.
I was thinking the same thing.
I agree. I think the book was wrong. I THINK that an electric current passed thru the molten metal would do better to dissolve aluminum oxide back to aluminum and free oxygen and hydrogen.
Put the salt in a foil foil packet and push it under the surface to mix in.
how is it supposed to degas if your just mixing it at the top, try putting it in some aluminium foil and holding it at the bottom. there are so many factors that cause bubbles, and one factor that will make a difference depending on where you live, I've never been to Australia, but where I live (which is the same place as myford boy) the UK has more moisture in the air which the aluminium absorbs and splits the oxygen and hydrogen and creates hydrogen gas.
love your videos though, especially the cast iron ones.
In the book it says it will remove hydrogen as a flux but it will float on the top only. Salt will absorb moisture so if it is plunged to the bottom it will bubble.
I use straight chlorine tablets that have been crushed into powder. MAKE SURE YOU USE A FAN SO TO NOT BREATH FUMES
You're right that NaCl or KCl solid salts won't work as everyone is using them. I think i've seen an older video of yours on the same topic. I believe part of the mythos of this ritual is based on a misunderstood fact though. NaCl/KCl solid solutions _are_ used as the basis for aluminum fluxes, but they must be in a solid solution before they'll melt at a low enough temperature to be effective. I also don't know how well the salt mixture does by itself. It may only serve as a mechanism of lowering the melting point of a more important component (in my case, CaF2)
Page 131 of "Handbook of Aluminum' by Totten, MacKenzie shows a phase diagram of a NaCl-KCl-CaF2 aluminum flux. The melting point of the eutectic mixture is about 660C. I've made this flux by dissolving fluorite (CaF2) in molten salt mixture. The accuracy of making homemade flux this way is troublesome because absorbed moisture throws off the weights unless you roast the salt first.
The flux I've described melts a bit higher than the aluminum flux BCS sells, but it performs the same. The foamy metallic dross will separate to a loose grey ashy material, and your metal loss rate is minimized. I even went and recovered a bunch of ingots out of my old dross bucket. I've tried other gimmicky household things, and they only made more metallic dross. I think most people don't really understand what to expect of a dross cleaning flux, so the remaining claims tend to be the ones that are the least easily disproven by eye at 240p (e.g. degassing performance).
As far as degassing goes, i don't think it really does any good for that. If anything, you've just demonstrated my point about how much water is in salt stored in permeable containers. That moisture does anything but degas metal.
Oh. Before anyone asks:
NaCl-KCl mixture is roughly equimolar or ~4 parts NaCl / ~5 parts KCl by _DRY_ mass
CaF2 should be about 5% by mass.
Inaccuracies only result in a higher melting point.
Large crystals of CaF2 won't melt simply, but it will slowly dissolve in the molten salt, so give it time.
Alternatively, pottery materials suppliers sell CaF2 flour as a fluxing component for ceramics/glass/glazes.
IIRC, Laguna lists it as "Fluorspar, Superfine'.
Keep the ground flux in an airtight container.
Thank you for the info.
you're welcome
I should add:
if the book isn't on google books anymore, a quick search for the paper "Solubility of CaF 2 in NaCl-KCl salt flux for Al-recycling and its effect on Al-loss" by Milke et. al should provide a superabundance of info on NaCl-KCl-CaF2 mixtures, phase diagrams and all that lovely jazz.
Also, regarding degassing, Pyroflux P-40 is listed as a specialty flux for cover/drossing with mild degassing ability. This product is an unknown mixture of KCl-MgCl2. I haven't gone looking for info on
KCl-MgCl2 binary solutions, but I imagine it's whatever ratio yields about a ~650C liquidus. Might be something to think about for any curiosity-motivated future experiments, but once we're talking about grinding/roasting/melting/mixing/casting/grinding a bunch of salts to make flux, the attractive simplicity of using ubiquitous products kind of evaporates. These fluxes aren't terribly expensive.
Dream Services International pls can I just add up sodium chloride and potassium chloride and mix it up with fluorspar and use as flux in scrap aluminum melting or must I heat up the sodium chloride and potassium chloride and fluospar to a molten state before using the composition as aluminum flux?
Heat up aluminum suspend in beaker of chlorine solution and it will keep generating chlorine
Sodium Carbonate will degas, Lite Salt works as a flux.
I m not sure of the salt. It would have to be sodium chloride also wonder if you poured from one flask to another.
Robert Anderson Salt is sodium chloride my friend
Good day sir! I have tones of aluminum chips here. Can you help me figure out how to melt them and turn it into an aluminum block? Thanks a lot!!
Sell it to a scrapyard and buy aluminuim car wheels.
It would break down with electrolysis.
I am glad you clarified this. I have read several Ammen books and thought he was an authority of the foundry art. Just as you have dispelled many other myths in foundry work it just goes to show 'Proof of the pudding etc'. Looking forward to your next episode. :-)
When writing books most people don't check what they write about and it does lead people in the wrong direction.
you have with your videos @@luckygen1001
Always been curious as to why some people pronounce Aluminum (Ah-loom-In-Um) as Aluminium (Al-ooo-men-ee-yum)? Lol hopefully this is understandable haha. Honestly though, there is no extra letter I in the last portion of the word so I'm curious as to how one would read it that way or even pronounce it as such?
It's actually kind of a convoluted story, worth a google search if you like science history.
If you read the history of the word it actually originated as "aluminium", and is still pronounced as such in many parts of the world :)
Flux me, didn’t this open a can of worms hahaha 😂
So are you saying that the book was wrong? If so, from your experiments what is the best solution that you have found to date?
I don't bother degassing.
Don't overcook your aluminum. Then degassing isn't needed. Took me ages to learn this.
You can use sodium carbonate, wearing a mask cause of some toxic emanations but for "home casting", degassing is like unecessary... just my point of view.
@@verdatum what determine the aluminun whether they overcooked or nor, is it the high temperayure or let them stay in molten temperature for a long time?
@@calvinsalim2375 the latter. Once molten, it turns into a magnet for gas.
But,,,,,,,,,, salt is usefull,,,, it melts and floats on top of the melt,, shielding it from oxidation,,,, its a flux.
Try calcium hypochlorite
Why that particular chemical?
The melting point for NaCl is 801 °C so how could it go into a solute form if your Al is below that? If it could and there was H also dissolved in the Al then you could get HCl (hydrochloric acid once it dissolves into water) But what happens to the Na? It could form Na2O if it can rob some O from any oxides present, otherwise from the air on the surface of the melt. So it sounds like it is one of those things that only works under specific conditions, which the book does not define, and that is poor technical writing.
You need to try this out and if you can get chorine gas from salt without passing an electric current through it let me know.
In my other comment, I describe a NaCl-KCl-CaF2 flux. The fact that eutectic solid mixtures like this have much lower melting points (660C) than any of their components and utilize additional fluxing agents (CaF2) leads me to think that this whole "dump salt in there" fad is just cargo cultish nonsense based on the misunderstanding of actual products. Then again, i'm just talking about drossing. Idk that it does anything for degassing, but the fact that it's hard to prove it doesn't degas (without material testing) means that's the claim that persists.
Throw the book away!
Mature Patriot he has addressed degassing in one of his vids. This man is a true master of casting. Need to sub to his channel it's one of the few that has no ads as I believe he has a true love of showing his art and sharing of his knowledge.
240p really?
lol
Large grain salt is a problem
Smart man
Took a whole year to stir it
If that's pure sodium you have there, when not sealed it should be stored in oil. It will react very violently to water, even the moisture in the atmosphere could be enough to set it off. If you haven't seen it before, carefully and from a distance, drop a very small piece (match head size or less) into a pot of water and watch the reaction!
A friend gave me about 1/2 kg of Metallic Sodium, it was in a glass jar of Paraffin oil. I used to cut off a piece, throw it on the ground and hose it with a spray of water. The reaction was very violent, an explosion and ball of molten metal.
if you dont plunge it its worthless.
Chlorine gas has no odour, the smell you get in a swimming pool is the chlorine reacting with contaminants in the water, i.e. urine, sweat and oils from the swimmers. The reaction creates chloramines which is where the odour comes from.
Saltwater pools (fresh water with salt added--about 3000 pm; ocean is like 10x that) have a salt cell/generator electrode that the saltwater passes through. As saltwater passes through, electrolysis occurs, splitting the salt and water into hydrogen and hypochlorous acid (HOCl). I'm not sure if introducing electricity into a crucible would work! But Darren is correct: chlorine is odorless...public swimming pools have that "chlorine smell" but it is indeed chlorine reacting with sweat, urine, oils, etc. that produces the chloramines that can bug one's nose, eyes, and skin. Chloramines are formed when HOCl reacts with ammonia--a component of sweat, urine and body oils. Anyway, more than you wanted to know!
Terribly sorry chlorine has a strong pungent odour, I taught the chemistry of chlorine for more than 30 years. Chlorine is a yellowy-green dense gas with a choking smell. That is the opinion of the Royal Society of Chemistry! Or try ua-cam.com/video/BXCfBl4rmh0/v-deo.html I don't know where you get your "facts" from.
Yes Stephen I agree. Anyone who isn't just Regurgitating "Facts" KNOWS Chlorine does have an ODOR and If they had generated Chlorine Gas and SMELLED IT they would Never Forget that experience IF they Survived.
>Chlorine gas has no odour
on the bright side, this is a lot funnier 2 years into COVID
You are not going degas just playing around the top of the melt. This guy has no idea what he is doing.
zippy, if you knew what you are talking about you would consider the displayed information more deeply.
first of all the the salt did not melt nor decompose at the temperatures of molten aluminum. if the salt did not decompose to sodium and Chlorine then it would not react with any hydrogen or be able to degas the aluminum.
all that happened with the salt was that the entrapped moisture was released - a very important point.
Now for all those mistaken people that wrap the salt up in foil and submerge it in the molten aluminum there is a bigger problem. the massive air bubbles produced is not from the degassing of the aluminum but from the expanding gas that was trapped in the foil when it was wrapped. Looks good but makes the problem worse.
next to make things even worse- the moisture that was in the salt is released deep within the molten aluminum and makes any entrapped hydrogen WORSE.
So go suck, wrapping anything in foil and submerging it in the melt, makes the entrapped gases worse - the bubbles are the gasses you were trying to prevent entering.
He says so himself at 7:20!!
Did you even watch the video?
It smells disgusting when you put into it. I tried it before.
the swimming pool smell is actually chloramines. chlorine gas is much harder to detect by smell