fluxing with wood...

[quiknot]

did i hear right that one way to flux is to just stir the hot lead with a piece of wood?

[grumpy one]

The short answer is yes. I've used sawdust and stirred it in, and I've used flakes of old water-damaged chip-board, and both work well. When I've used a stick the stick hasn't lasted all that long. I prefer to stir wood dust or flakes through the mix, because the process seems a lot more active that way - but I also find that so long as I hold it for a few minutes at around 650F, it doesn't seem to matter whether I flux or not anyway, the crud either floats up, sinks down, or sticks to the sides of the pot. I can get the sunken stuff to the surface fairly effectively by stirring with a stainless steel spoon - the crud is much less dense than lead, it really wants to get to the top if it gets a chance.

Seems to me the main thing is not to use anything that makes noxious fumes. Wood smokes, and the smoke stings the eyes a bit, but is practically perfume compared with what happens with tallow.

[garandsrus]

Quiknot,

I have done that and it works well. I usually throw in some sawdust also. Make sure the wood is dry and immerse it in the lead slowly so that any moisture can evaporate before the wood is immersed.

John

[wiljen]

I've used sawdust and even ground walnut husk in a coffee grinder and used it when sawdust wasn't abundant in my shop.

[Junior1942]

Another way to flux is to not flux at all. I haven't in years.

[ron brooks]

Another way to flux is to not flux at all. I haven't in years.

Why not? No problems with dirty alloy or losing tin?

Thanks,

Ron

[Hunter]

It is my understanding that during smelting and casting the tin does separate from the alloy but I am no expert.

[NVcurmudgeon]

Years ago there was an article in Handloader by a metallurgist who worked for a lead/lead alloy company. IIRC, the man was not even a shooter, but he knew his metals. The article was chock-full of scientific information, enough to cause my eyes to glaze over. The summation of his article was that three-metal alloys of lead, tin, and antimony DO NOT gravity separate. I believe him completely. One bit of empirical evidence that is convincing to me is that when I weigh rifle boolits from a long casting session, weights are remarkably uniform. If the metals gravity separated, I would expect a wide variation of weights, reflectng a variable distribution of metals. I flux for the sole reason of getting the crud out. This is particularly important to me because I am a ladle caster. Were I a bottom-pour kind of guy, I would use a layer of kitty litter and never flux, but stir occasionally to get the crud to surface and join the kitty litter.

[VTDW]

My preference is a paint stir stick. It is great to flux, scrape and stir.

Dave

[Junior1942]

Why not? No problems with dirty alloy or losing tin?

Thanks,

RonThe metals are in solution and don't/won't separate. Fluxing ww alloy to keep the tin and antimony in solution is like fluxing sea water to keep the salt in solution. The crud on top of the melt is just that--crud. Discard it and cast.

[ron brooks]

The metals are in solution and don't/won't separate. Fluxing ww alloy to keep the tin and antimony in solution is like fluxing sea water to keep the salt in solution. The crud on top of the melt is just that--crud. Discard it and cast.

Okay, I'll give it a try.

Thanks,

Ron