Appreciate your effort! But the pour was too cold. Temperature has more effect than degassing. Degas during while heating

To me it seems a bit weird to keep one sample out of the furnace for so long before pouring and expect comparable results.

the CO2 treated sample looked worse to me. But it was also poured cooler, both time and the CO2 passage removing heat.

I could not agree with you more!! I have found that just melting aluminum at a fairly mild rate then removing the dross yielded an aluminum cylinder free of voids. I have recently machined 2 of these into perfect cylinders for a model steam engine.. Thanks for performing all the research.

@luckygen1001

7 жыл бұрын

If you can make a video of it running.

Sodium carbonate will also pull CO2 from the air, as well as water, to form the bicarbonate. That breaks down at low temps to give the carbonate again.

I think you're exactly right. There's a guy who uses calcium chloride which may work so I bought some to try it out. It's used in swimming pools and inexpensive. Maybe it will work. Probably the best advise I heard was to not let the metal get too hot and pour within 3 minutes after it's melted to keep the heat down. I melt the most awful stuff, anything I can get my hands on so it almost always has porosity. Anyway, this video was very informative so thanks for making it.

Great video, I found it very interesting. Good to see another Aussie mucking around in the shed.

I'm like Fred, I have never had a problem with gases if I pour as soon as it melts, now if I go past the melt time it will quickly develops gass so I try to avoid getting it any hotter than I have to. on another note, I've seen Martin (Oldfounsryman) use Argon I believe where he injects it into the melt under heat. I was really surprised you didn't freeze your melt pushing room temp co2 into the melt outside the furnace which makes me wonder how how your aluminum was. Thanks for the demonstration, as always you do a great informative presentation. When people ask me where I picked up my new trait I always give you major credit for it. And I haven't forgot to do a video on an iron pour, have to wait for my daughter to be here to film it but I hope to do that soon.

@luckygen1001

7 жыл бұрын

Thank you for watching my video. Aluminuim will stay as a liquid for many minutes with a A12 crucible out of the furnace. Did you notice that the second experiment the aluminium was a lot cooler? It still was hot enough to pour after the experiment. As my camera does not zoom very well I had to film the crucible outside the furnace. I am looking forward to your iron pouring video!

after some thought your problem is mostly oxygen so doing this in an oxygen reduced atmosphere would stop most of the out gassing of your molten aluminium if you pack your crucible with aluminium and add a small piece of charcoal then seal the crucible until you are ready to pour the charcoal will suck up o2 and can be scooped out with the drause good luck and the crucible can be sealed with wet bentonite clay and the allowed to dry before firing.

Very enlightening. I have had porosity/gas pitting in my castings and I had been following the trend to use soda. I did buy some degass cake from a foundry supplier which does react more violently but I still get very minute pores over quite a large area. After watching this I will try without adding anything! Cheers for another great vid.

@luckygen1001

7 жыл бұрын

Dirty, oily and corroded scrap will be the cause of porosity. Remelting scrap from the last melt causes more build up of porosity. Try to use very clean scrap.

@creast56

7 жыл бұрын

Thanks. I can see your point there. But its a shame not to be able to reuse leftover melts. Any suggestions?

@luckygen1001

7 жыл бұрын

Use left over scrap from the last melt for unimportant jobs, not all castings need to be porosity free.

You don't need to degas aluminium.. additives only create Gas bubbles not remove Gas. Just heat it to casting temp (750C) and pour it quickly.

thank you again for a informative show

My guess is that your metal is alot warmer on the 1ste pours, because after the 1ste pour the molten metal sits outside of the furnace so the metal is alot cooler after degassing.

@myharris

4 жыл бұрын

I was surprised to see the sodium carbonate added outside the furnace - I've had good results with soda crystals, but I add it while the crucible is still in the furnace. I hold it down in the melt with a stainless steel cup till it stops off-gassing, then sprinkle table salt as a drossing flux, give it another minute or so, scrape off the dross and pour at 700deg.C. Never had a porosity problem yet.

What your humidity level was at the time of casting makes a huge difference.

The temperature difference between the pours was really bad so I would take this with a grain of salt but you have all my respect for going after the exact causes with actual analytical chemistry

Whats your opinions on using pool shock instead? Ive used pool shock for a while and it seems to help alot here. I believe it is calcium hypochlorite.

@luckygen1001

7 жыл бұрын

I have never used pool shock but if it bubbles chorine gas it works so much better than other gases. It can be very toxic so do it outside.

Fascinating. Thank you.

Hi, it is a very interesting video and you tel all the true about it. I'm new in metal casting and learning a lot with you. Thank you very much. Please keep doing more video. Best regards

Thank you for making this video it was very informative.

I think a better idea is wetting it and driving the moisture our afterward so you get chips instead powder which is gonna blow all over in your foundry and probably react with the walls, borax does very well with this method.

I really enjoyed this video, thank you

Good day Mr Luckygen when I was a Millwright apprentice some years back working at a aluminum smelter they use a process known locally as RIF there was a graphite rotor that was hollow and wold stir the aluminum while argon gas was pumped thru it. Now I´m a Millwright and not a casting man nor metallurgist. But I remember asking about the gas we cold feel ( more like taste I suppose ) when working over the refining ovens and I was told it was a Magnesium salt that was used for refining ( this was a primary metal smelter aluminium oxide to reedy to role billet material) now I still have some connections to the smelter so I can ask for further clarification. Are you familiar with something of the nature ? Best regards form Iceland

@luckygen1001

5 жыл бұрын

Yes I am.

That's very interesting. Given that you have shown CO2 and sodium bicarbonate isn't great for degassing, what would you use instead?

@luckygen1001

7 жыл бұрын

There is no cheap backyard fix to degas aluminium. All commercial foundries use nitrogen or argon but for us small melters it is not worth the expense and trouble to do it. To keep gas levels low do not melt left over metal from the last melt.

@RaspyOB174

4 жыл бұрын

I know that in the U.S. there is a fairly easy ability to obtain nitrogen via paintball gas providers. It takes a particular bottle and a charge up fee. Also argon is easily obtained through welding suppliers. May be worth a try to obtain a bottle of each and test it with the gas lance!

Good videos man. Metallurgy in the back yard... Thanks for that. A) I have read in several locations that bubbling argon gas with a lance through the molten aluminum will reduce (hydrongen) gas bubbles in the solid metal. Could you confirm this effect? I have seen one cast alloy rim manufacturer do it. B) I have seen youtubers melt aluminum at home and having practically no porosity at all without any form of degassing? Have you seen such samples too? C) Does the porosity depend on the local air moisture or is it caused by the water vapor in the exhaust gas after burning oil or propane which produces CO2 and H20?

@luckygen1001

5 жыл бұрын

Thank you for watching this video. A) All foundries use argon or nitrogen to degas their aluminium and none of them use sodium carbonate to degas their aluminium. I have never used either gas to purge hydrogen porosity so I cannot comment on that. If a foundry is pouring castings for the public they would not use a method that does not work.B) If you are careful when melting aluminium there will be little porosity but having said that castings that have very thick sections will cool last and that is where you will find some hydrogen porosity. There will always will be some porosity. Ask yourself the question why do foundries go to all that trouble to degas when some youtubers don't? Those castings that youtubers pour will have some porosity if examined knowing where to look for the porosity. C) Yes there will always be some moisture in the furnace atmosphere and in the scrap you are melting. Some alloys absorb more hydrogen than others, also when aluminium alloys are over heated they absorb a lot of hydrogen. So can you see why it is counter productive to degas with sodium carbonate, all you are doing is bubbling steam through the molten metal.

This is a must watch video!

thanks, a very good vid. I wonder what would happen if you put the crucible in a vacuum for a short time. have you ever tested that?

@luckygen1001

7 жыл бұрын

That is the best way to degas aluminium but putting a hot crucible in vacuum chamber and pumping out the air is beyond most backyarders.

Very good info. Thanks very much luckygen.

Can you do the same test but use the same amount of degassing pallet? So we can see what the professional stuff looks like in the same amount? Also what about argon gas instead of CO2? There’s another Guy named Martin from Australia that cast aluminum also he uses are gone to the gas.

The co2 pour was too cold, I have quite a bit of luck with the borax though

Holy crap. How hot do you get it? I could never let a crucible of aluminum just sit that long. Granted, I keep my foundry temp down on aluminum melts because I watched 20 or so cans burn up as if they were paper when I dropped them in at higher temp (it was before I had my IR thermometer, but based on how long it was on, how much propane I was pushing into it and how high I had my forced air from temps I typically saw with my IR thermometer, I'd say it was around 1800-2000*F. It's a loose estimate, but it's all I can go off). So I always kept it down after that (around 1000*F), and actually retained some metal from the cans

@luckygen1001

5 жыл бұрын

Larger amounts take a while to cool down.

@The52brandon

5 жыл бұрын

@@luckygen1001 gotcha. I only have smaller crucibles (I suppose my foundry is quite small itself. But I'm in the process of a major upgrade with the added fuel option of waste oil, and added accelerant option of pure O2, to go with the previous combo of forced air and 0-30psi propane. Can't wait). So although I've done a high number of melts, none were much in the way of volume

What do you use for degassing? It would be nice to do this same test with something that is supposed to work like a professional commercial degassing chemistry.

@centurialinc

7 жыл бұрын

The only two degassers that are ever taken seriously are Argon and Nitrogen, (Dry) Compressed. They are noble gasses and the idea is to stir and push out any hydrogen using a mechanical not chemical process. But the point being made here is that not knowing the details are, is what is causing all the confusion. Using simpler techniques like no degassing at all shows much better results. An old saying comes to mind. The how is more important than the what. This video demonstrates a very scientific approach to brake down what is going on. We should all do the same. Best Matt

@luckygen1001

7 жыл бұрын

I do not degas because here in Australia nitrogen cylinders are very expensive to rent, also I do not melt a lot of aluminium so the cost is not justified. You need to look at olfoundryman youtube channel he has some videos about this subject and knows a lot more about aluminium melting than I do.

@luckygen1001

7 жыл бұрын

Actually nitrogen is not a noble gas because there are so many compounds, ie ammonia, nitric acid but it is unreactive to molten aluminium.

@centurialinc

7 жыл бұрын

After I typed that I realized the mistake. Just the argon. I'm happy you found it to :) Thanks for the fantastic videos. Best Matt

@Gippetos

7 жыл бұрын

I amfinding your channel quite informative with all the myth busting and demonstrations/experiments. Appreciate you taking the time. :) Will check out olfoudryman. Cheers, Al

If you want to degass molten metal (remove entrapped gasses), why wouldnt you put it in a vacuum chamber and pull a moderate vacuum for a period of time.

@luckygen1001

5 жыл бұрын

It is the best way to degas aluminium but getting a vacuum quickly can be a challenge.

Hi, I'm interested in the green sand formula, I already have 400 mesh silica sand, calcic bentonite, and a little bit of cornstarch, do I need something? What proporsions do you use? I would appreciate the information I am a student of mechanical engineering interested in aluminum casting.

@luckygen1001

5 жыл бұрын

I use 7.5% bentonite for my sand but for other sands you may have to use more or less depending on how coarse or fine the sand is compared to mine.

@albertfunes5775

5 жыл бұрын

If it were thinner should I use more bentonite?

the veg oil guy has figured out a good way to vacuum molten metal, and black beard projects made a good simple vacuum chamber

Tnx a million! Great work! So what is the best n easiest to use? Could u please tell us?

@luckygen1001

5 жыл бұрын

Argon or nitrogen will work but there is no easy way to degas aluminium.

@KAYAPOGAN

5 жыл бұрын

Thank you again! Good luck!

Use argon,degass at 1300 and flux the metal to remove impurities

Thanks for sharing your research, Can you confirm the aluminium was heated with propane torch? Im of the understanding that propane will burn with CO2 and H2O as outputs, leading to some humidity in the kiln, whereas electric furnace (dry heat) may be better for keeping a dry atmosphere around the melt. It is one of the reasons I am working on the electric furnace build, but i know little of the art of foundry :-)

@luckygen1001

7 жыл бұрын

Yes it was melted in my propane fired furnace. This why fuel fired furnaces need to have the air fuel mixtures correct.

@JBFromOZ

7 жыл бұрын

thanks for the update :-)

@6226superhurricane

6 жыл бұрын

Aluminium actually

have you considered cannibalizing a refrigerator to make a vacuum pump to pull vacuum to degas?

@luckygen1001

5 жыл бұрын

Using vacuum pump is the best way to degas aluminium but takes too long to build up a strong vacuum.

@claytonmccormick7506

5 жыл бұрын

@@luckygen1001 what you need is not hard vacuum but a high volume of low grade say 10 to the minus 2 torr there are 2 ways to achieve this 1 only evacuate a small area 2 us a large pump harbor freight have compressor pumps in the 3 to 5 h.p. range for 144 to under 200 dollars you would need to find an electric motor of appropriate size but you could use the intake as a fairly robust roughing pump i would use both so you can degas quickly while the metal is still molton ,steam casting is the reverse uping the pressure to reduce booble size i would use all three methods with the luck you have been having.

@11Aldebaran11

4 жыл бұрын

@@luckygen1001 How about that. Instead of use a vacuum pump, lets built a vacuumed cylinder or accumulator. First cover the crucible with melted aluminum with cover that will make crucible airtight, and then connect this cover with pipe to the vacuumed cylinder. After all this, open the cylinder regulator slowly, so the vacuum will continued to the crucible in less density of course. Please consider that English is not my native language (Greek speaking lunatic :-) ) I tried my best to passed to you my idea. Regards to All.

Aluminum soda?

I'm gonna try throwing some sodium metal in.

Surely you have a better camera than the one you use for all your videos. No hate man but it's about time to upgrade to at least 1080p. The latest iPhones all shoot in 4k60p

Is there any hidden dangers to this? Also should I wear a breather?

@luckygen1001

3 жыл бұрын

It just produces steam.

Olfoundryman uses argon gas for 7 minutes for good results

So do you need to degas aluminum?

@luckygen1001

6 жыл бұрын

It all depends how fussy you are. I don't bother because of all the costs involved renting argon bottles. What electronics are you interested in?

@hobbyelectronics6630

6 жыл бұрын

Lately I have been playing with nixie tubes. I am thinking about casting a clock base with lost foam. I have 90% argon 8% co2 MIG gas. Do you think that might be worth a try. I didn't think salt, washing soda or co2 would do anything. Thanks for clearing that up. You saved me a lot of wasted time and effort. I rather expected that clean scrap equals clean casting.

@luckygen1001

6 жыл бұрын

You could give the 90% argon 8% co2 MIG gas a try, it has to be dry otherwise you put in more gas. Yes you are so right clean scrap does equal clean castings.

Aluminium reacts with CO2... Argon or helium would be better...

More people should be watching this video and stop doing the silly things a few are promoting on KZread as a method of degassing. The proper methods of melting are a correct flame balance and melt temperature and time to molten. Keep the time to molten and poring as short as is practical. Less gas will be entrained in the melt.

I LOOKED AT THE CHEMISTRY OF THE ALUMINUM OXIDE AND DEGASSING TECHNIQUE. I HAVE NOT HAD A CHANCE TO TRY THIS BUT I THINK IT WILL WORK MAKE PURE ALUMINUM. I WILL TRY IT ASAP. INSTEAD OF "DEGASSING WITH SODIUM CARBONATE" TRY THIS TO CLEAN THE MOLTEN METAL. RUN AN ELECTRIC CURRENT THRU THE ALUMINUM METAL JUST AFTER THE ALUMINUM TURNS MOLTEN. CONTINUE HEATING THE OXYGEN SHOULD BUBBLE OFF NEXT TO THE anode and hydrogen will bubble off next to the cathode. USE COPPER WIRE To STEEL ELECTRODES OR GRAPHITE ELECTRODES. LEAVE THE CURRENT ON UNTIL THE BUBBLES STOP. ALL OXYGEN AND HYDROGEN SHOULD BE REMOVED. THEN FLUX AND REMOVE THE DROSS. SHOULD BE VERY SMALL AMOUNT. THE CURRENT SHOULD CHANGE ALUMINUM OXIDE BACK TO PURE ALUMINUM. ALUMINUM SHOULD BE CLEAN AND PURE WITH NO BUBBLE HOLES.

@luckygen1001

5 жыл бұрын

Let me know when you upload the video I will watch it.

@TheRealCreepinogie

5 жыл бұрын

Good luck.

Start of the ally was to cold

I dont think your chemistry is right on this...you are trying to take carbon and oxygen out of the aluminum solution

@tomharrell1954

4 жыл бұрын

No! He is trying to remove hydrogen!

Way to science the shit out of that one! Love it. Cheers!

Argon not are gone. Sorry iPhone