Argon Purge

[15meter]

If you want to try wouldn't carbon dioxide be cheaper and do the same thing?

Or am I missing something?

[elmacgyver0]

If money is no object and you have plenty of ventilation, I would say go for it.

[JSnover]

I don't worry about the surface. I flux, stir, skim, and it doesn't cost a penny.

[Rickf1985]

Entirely possible the OP is a welder and argon purge is very common and necessary for a lot of stainless steel welding. Being a welder myself I could see why he would ask if he was looking at it from that angle. He may have also planned on building a containment for the pot. We will never know since that was his one and only post, he never came back.

[15meter]

Entirely possible the OP is a welder and argon purge is very common and necessary for a lot of stainless steel welding. Being a welder myself I could see why he would ask if he was looking at it from that angle. He may have also planned on building a containment for the pot. We will never know since that was his one and only post, he never came back.

Another drive-by posting

[Dancing Bear]

We used coarse charcoal in our large lead pots to reduce oxidation when I worked in a heat treat department many moons again. But that was at much higher temps then for casting.

[Hossfly]

Too expensive, I know what a 125 cf cyl. Cost to refill even if you own the bottle. Argon

[Rickf1985]

Another drive-by posting

And what, exactly, is that supposed to mean?

[Rickf1985]

Too expensive, I know what a 125 cf cyl. Cost to refill even if you own the bottle. Argon

Mine is a 250 cf., and it is almost empty! OUCH!!!

[JimB..]

OP joined on 1-18-24 at 10:43, posted this question, and was off by 11:01.
He hasn’t been seen since.

Just sayin.

[15meter]

And what, exactly, is that supposed to mean?

Exactly what it says, single post and disappears into the night.

Amazing the number who take the time to register, ask a single question then disappear.

[Rickf1985]

I thought you were talking about me! That's why I said that, I had three posts on this thread already. LOL I have the same thing on my forum, I was just looking at those figures today. over 400 people that have registered since 2007 and never posted again. But I do know for a fact that some of those are still on the board since I have talked to them at shows and they mention recent threads. They are the lurkers that just absorb the info without commenting. A lot of them feel they do not have anything to add to what is already being said. Smart people.

[kevin c]

Just because the OP has vanished doesn’t mean we can’t make this a worthwhile thread. So, in that vein:

Once you flux, just leave a layer of melted wax on top to prevent oxidation.

How do you do that, popper? Anytime I put beeswax on top of the melt, it melts, sizzles, sputters, and then starts wicking up the inside walls of the pot to end up burning onto the lip (unless I ignite it). Even a pea sized lump does this. Much less leaves a smoking grease spot floating on one corner of the melt surface.

[JSnover]

Just because the OP has vanished doesn’t mean we can’t make this a worthwhile thread. So, in that vein:



How do you do that, popper? Anytime I put beeswax on top of the melt, it melts, sizzles, sputters, and then starts wicking up the inside walls of the pot to end up burning onto the lip (unless I ignite it). Even a pea sized lump does this. Much less leaves a smoking grease spot floating on one corner of the melt surface.

I wondered the same thing. I just flux by stirring with a stick and letting the ash cover the surface.

[mfraser264]

Having worked in a steel casting and investment super alloy casting facility, have a little experience with this. We would cover the induction furnace when melting steel and then introduce Argon but were unable to seal the cover so the argon melts were done as quickly as possible as the gas bled off. It would displace the atmosphere and greatly reduce oxidation which was the reaction of the molten steel alloy with oxygen, nitrogen and hydrogen as we were concerned with.

Argon, being a inert gas, was injected sometimes while melting and pouring the super alloys which were nickel and cobalt. Mostly this was done in a vacuum furnace.

If the concern while casting lead alloys is re-oxidation of Tin, the reality is you will not loose enough Tin to re-ox in foundry terms to be concerned with. Once the re-ox is skimmed off, it cannot be refined with household equipment/processes anyway to slavage the Tin.

Have been casting lead alloys for 40+ years and yet to use any barrier materials on top of the melt. Will use the white metal specific fluxes however sawdust is not a flux. Sawdust wont 100% seal off the head of the metal charge as typical top top material will.

In college I used green and brown glass to as a re-ox barrier when melting brass and bronze and this did work well.

[jsizemore]

When I smelted window came the old caulk would make it's way to the surface when stirred and scraped and maintain an insulating layer for both oxygen and heat. Had to cut the gas back more than normal and had a clear shiny surface when the dross was spooned clean.

[justindad]

Just because the OP has vanished doesn’t mean we can’t make this a worthwhile thread. So, in that vein:



How do you do that, popper? Anytime I put beeswax on top of the melt, it melts, sizzles, sputters, and then starts wicking up the inside walls of the pot to end up burning onto the lip (unless I ignite it). Even a pea sized lump does this. Much less leaves a smoking grease spot floating on one corner of the melt surface.

I have microcrystalline wax that does this. To be complete - I have some left-overs from experimenting with the FWFL recipe, that includes MC wax and paraffin wax. It leaves a charred skin on the top of the lead. With pure beeswax - I get the same thing you do, with the liquid wax wicking up the sides of the pot.

[john.k]

Many use charcoal from a store bought packet .........I use charcoal salvaged from Clemco air filters ...used ones ,as new ones are over $100.......anyhoo,the theory is that charcoal is so light ,there is zero chance of any contaminating a bullet.

[john.k]

Incidentally,a special argon foaming spin probe is used to deoxidise aluminium alloys before casting.........this is because the oxide is the same weight as the metal ,and there is no other way of deoxidizing the melt...........Actually there is ,but it involves a certain level of danger ,and WHS hate danger.