Fluxing?

[S.B.]

Explain exactly what this process is(makes elements in alloy stick together or cleans alloy?) and why should I do it. Then, what you use for fluxing your alloy and why, please? Need to know just what I'm doing.
Steve

[jmsj]

S.B.
The best explanation I have read is at www.lasc.us/ Look for Glen Fryxell's article " The Simple act of fluxing". Hope this helps. jmsj

[S.B.]

jmsj, sorry but, much of the link you posted is very redundant. Could you post a direct link to this article, please?

Steve

[S.B.]

Never mind, I did a direct search and found the article you referenced. Do appreciate your trying to help.
http://www.lasc.us/FryxellFluxing.htm
Thanks, Steve

[Bret4207]

I'm not going to try and say what it does chemically. All I know is you get better boolits when you flux. I simply stir and scrape with a dry stick. The carbon released as the stick chars serves as an excellent flux and the stirring and scraping works to provide the mechanical cleaning and mixing we need. No flame, no smoke to speak of. Works great, simple.

[montana_charlie]

Explain exactly what this process is(makes elements in alloy stick together or cleans alloy?) and why should I do it. The term 'flux', when used in the rest of the world of metallurgy, has a different connotation than it does when we bullet casters use it.

I'm not certain that anything we do is truly 'fluxing', but we have two kinds of it.

When smelting a batch of scrap metal, any desire to control oxides is a peripheral concern. The object is to blend metals from various sources together, and remove all of the trash that came with them.

I use a big slotted spoon and 'wax' for this. Throw in a chunk of wax, stir it around with the spoon while giving the pot a thorough scraping, and skim off the junk.
That leaves the metal clean enough for pouring ingots to be stored.

When casting bullets, I consider any form of 'wax' to be a contaminant. I won't use it for 'fluxing', or as a lube on my moulds. Like many others, the simple wooden stick is my 'fluxing agent' of choice.

The thing is...the object is not to clean the metal. That was done at smelting.
The goal now is to control oxides.
The grey sludge which forms on the surface of clean metal is made up of oxides from every metal that exists in the alloy.

In an alloy containing only lead and tin, the ratio of tin oxide in the layer of sludge will be slightly higher than the ratio of tin in the alloy...because tin oxidizes more readily than lead. Simply skimming the sludge off not only discards good metal, it also begins to modify the ratio in your alloy.

Returning oxides to the metalic state is called 'reduction', and the carbon from the 'fluxing stick' causes that to occur.

With this basic explanation, you should be able to formulate answers to the questions you asked.

CM