Fluxing

[I Haines]

Will someone explain the mechanics of fluxing? What is the purpose and how is it achieved? Thanks in advance.

[lwknight]

This has been covered in great detail and debate in numerous threads.

Basically the word " fluxing " is misleading because we actually are reducing oxides back into solution by introduction of hydrocarbons like wax to steal the oxygen atoms away from the metal oxides.

You have 2 parts to the fluxing process.
1. A little wax on melted alloy will break the surface tension and free particles of contaminants to be released for skimming off. This is most helpful when smelting scrap and skimming the crud that comes with it.

2. Your nice clean alloy will always be oxidizing and eventually you will want to reduce the oxides back into solution because you lose tin more than anything else if you simply skim ff the skin on the surface.

The process is dirt simple. Just toss a small ( pending your pot size) peanut to pecan sized chunk of wax or a coating of sawdust onto the melt and stir the peewaddly out of it. Dunk, crush, mash and smash it till you end up with nothing but carbon dust if you want it all saved.
Warning!! Wax will auto ignite and make you hurt yourself!!
Light it on fire if it does not auto ignite to stop the smoking.

[runfiverun]

it's introducing carbon into the alloy helping the alloy bond and releasing the dirt.
lw pretty much covered it.

[HighHook]

lwknight, Thanks for the great info...

[onesonek]

This has been covered in great detail and debate in numerous threads.

Basically the word " fluxing " is misleading because we actually are reducing oxides back into solution by introduction of hydrocarbons like wax to steal the oxygen atoms away from the metal oxides.

You have 2 parts to the fluxing process.
1. A little wax on melted alloy will break the surface tension and free particles of contaminants to be released for skimming off. This is most helpful when smelting scrap and skimming the crud that comes with it.

2. Your nice clean alloy will always be oxidizing and eventually you will want to reduce the oxides back into solution because you
The process is dirt simple. Just toss a small ( pending your pot size) peanut to pecan sized chunk of wax or a coating of sawdust onto the melt and stir the peewaddly out of it. Dunk, crush, mash and smash it till you end up with nothing but carbon dust if you want it all saved.
Warning!! Wax will auto ignite and make you hurt yourself!!
Light it on fire if it does not auto ignite to stop the smoking.

Indeed!

Being new to casting myself, I hadn't read enough or all on fluxing/reducing as I thought ,,,untill I read a similar post.

lose tin more than anything else if you simply skim ff the skin on the surface.


I was,,but fortunately I saved the dross. Some 50# of boolits later I melted the dross down, and recovered a bit over a pound of good stuff.

Dunk, crush, mash and smash it till you end up with nothing but carbon dust if you want it all saved.

Started doing that, and the dross was reduced to the point of what was being removed from the pot wouldn't fill a .22short case on a 20# pour, and that was likely more ash from my stir stick than anything. Of which, I found 1/2-5/8" hardwood dowel rods from the hardware store works best for me. Even being round, it still pushes the dross/oxides to a pile to the back of the pot. Which I do after about every 1/4 of the pot. The dowel end is big enough to dunk the oxide pile a couple times and hold it under a few seconds. The remaining stuff that floats back, I roll out against the side, I can see the remaining tin/alloy squeeze out) and the bulk of the ash sticks to the dowel which I tap off on the edge of the dross can.
I use wood shavings (CFF) to reduce that initial startup, once the the alloy is up about 600-625*. Seems to reduce that funky layer of tin/antimony on top quicker than wax for me.

[I Haines]

Thanks for the info. Is fluxing pure lead necessary?

[lwknight]

Thanks for the info. Is fluxing pure lead necessary?

The word "Necessary" is a realitive type term.
You will lose a lot lead in dross/oxides and you can recover most of it if you want to work it. Whether its worth it or not is in the eye of the beholder.