Degassing aluminium with argon gas

[@aliquis07]

Hi, thank you for sharing your videos with us. Argon is the right way to degassing Aluminum, after to see your video I see 3 things that might help to improve the experience. 1. five minutes could be a good time to degassing but your metal could get cold meanwhile, why not try to do this inside the furnace adding a metallic cover on the crucible in order to avoid losing metal and increase an Argon atmosphere inside the crucible. 2. try to pouring the metal like a common piece, you know pouring the metal directly to the mold causes turbulence, so I think some of the porosity is because of turbulence pouring. 3. Do not forget the shrinkage porosity, maybe you can use a suitable riser on the piece, in order to avoid this type of porosity and not confuse both kinds of porosities. all are only suggestions, have a great day.

[@sarahnikas1344]

Your videos are highly underrated. Thanks for the info.

[@deltajegga]

was the lance stainless steel? did you have problems with the aluminum dissolving it? i tried a small tube of stainless steel and it blew out a hole in the side after the second use. but a graphite rod bored out on a lathe with a long drill bit works good though.

[@kentuckytrapper780]

Try melting aluminum car rim's it's the best quality aluminum ive found. Great info thanks.

[@kentuckytrapper780]

@John Doe nothing, I've tried a little of everything but nothing does just as good. Get it to the perfect temp is the key..

[@kentuckytrapper780]

@John Doe 1250 to 1300 degrees F usually does the job. Good luck.

[@dennisyoung4631]

“Time for ORGONE…” Note that I’ve named my TIG cylinders *Orgone Accumulators.*

[@p2p583]

For how long do you degas the aluminium?

[@ronnybraswell588]

Did you watch the video? He clearly explained that.

[@IndyRockStar]

could you just run the argon through a fish tank air stone?

[@turtlemann14]

problem would probably be that the heat shock would crack the stone quickly. on the other hand, if you could force enough argon through it it may stay cool enough and work.

[@dennisyoung4631]

Perhaps use a drilled graphite rod? Only issue I have yet to figure is how to rotate the rod while still flowing the Argon/nitrogen

[@turtlemann14]

@@dennisyoung4631 simple rotary coupler would solve that. i like where you are going here.

[@dennisyoung4631]

@@turtlemann14 I’ve been wondering how to do this matter for my own use in foundry service, on a small scale, i.e. A10 crucibles and smaller, without spending huge amounts of money. Another issue is that one really wants a *small* flow of chlorine in addition to Argon or Nitrogen. The chlorine chemically combines with hydrogen, while the other gases merely displace it.

[@tomasjosefvela1]

@@dennisyoung4631 maybe chlorine tablets crushed into a fine powder, the ones used at the spa (used for the pedicure stations) can be bought in more affordable amounts than the ones supplied for a swimming pool

[@JC-iq9gv]

Genuinely interesting !!! In ‘’ THE HOBBYIST'S GUIDE TO CASTING METAL’’ of Ben Baker, there is a lot of information about hobby casting and especially about degassing aluminium. Your attempt of degassing with an inert gas as your soda one are mentioned. There is also a reference to another degassing technique based on chlorine. Worth to have a look. May be you have that book.

[@metalmusings]

I have seen chlorine, and as I understand it right it is the most efficient degassing gas. But everything around starts to rust from the chlorine, so I'll pass on that. I would be easy to test using tablets for pool. I don't have a book on the subject, I rely on my google skills. I just hope it doesn't say that na2co3 works haha.

[@JC-iq9gv]

To answer your question, you can google the title of the book ;-)

[@gizish]

What is the name of the book?

[@JC-iq9gv]

See my first post ;-)

[@gizish]

@@JC-iq9gv oh haha. Thanks!

[@canadianoddy8504]

The problem was the size of the bubbles. The bubbles must be less than 3 mm. This has to do with surface area. Also your pressure was way to high. Apparently you run 1 1/2 LPH on the argon. I just watched a video made by an Australian guy. It's the best video every made explaining degassing in my opinion. I will incl a link here but not sure if I can attach it to your video. The poster is called: Olfoundryman Here is the video link: kzbin.info/www/bejne/b3uXipJtfKigj8k By the way your video is good but there are issues that need fixing.

[@tomharrell1954]

Excellent if you want to get the aluminum perfect the argon gas must be very small bubbles like foam !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@metalmusings]

Yes I have got that comment before and I think that is right. At least it didn't make a difference the way I did it.

[@olfoundryman8418]

Thomas, Yep, dead on - should be sized like foam on a beer. Damn hard to get you really need a rotary degasser, best I can from my 0.1 mm slot is 1 mm on a water test which means 2 to 3 mm in aluminium. Blowing argon out of the end of a pipe (or even 1/16 inch holes) is like farting in a bath and about as useful. A 1/16 inch hole will give a 6 to 10 mm bubble size in aluminium... Martin