A thought on fluxing.

[Seeker]

I did some smelting today and used pine sawdust for fluxing. While I was at it I got to thinking... I wonder if dried out pine needles would work? I have tons of them lying around.

[RogerDat]

If said pine needles had anything with moisture such as a bit of wet dirt or tuft of stick with wet bark and you pushed that under the surface of molten lead the explosion would be unpleasant. That said I think about anything carbon based and organic can work. But the tinsel fairy takes revenge on all those that use anything damp in molten lead.

Bag of wood shaving rodent bedding from the big box store or pet store is cheap, dry and easy to store.

[JWFilips]

I have a few white pines that ooze sap over the year: It hardens into rosin ( I think) This is a great addition to my sawdust flux when smelting. Wouldn't want to use it otherwise....just for the nasty removal of junk in the Smelt! Very smoky

[bangerjim]

Sappy pine is excellent for flux in the re-melting process. DRY is the key word.

I have a HUGE pine and needles all over the driveway that have sap in them. The sap makes a good flux.

[scottfire1957]

Yeah, they'll work fine. Make doubly sure they are dry. Let them sit atop the melt, without stirring, for a while.

If you can dry beforehand, that also helps.

[country gent]

Like sawdust or wood chips you would need to sprinkle them on top of pot and wait for a few minutes for them to dry. With wood chips I add a little paraffin and light it starting the charing process much faster and getting rid of moisture faster. Any thing added to a pot of molten metal needs to be added slowly and allowed the heat to remove moisture before being carried under the surface

[waksupi]

Stirring your pot with a good dry stick works just as well.

[mold maker]

Stirring with a dry stick does work, but is a good way to get charred wood against the walls and bottom of the pot. The surface tension will hold it there and as the lead level drops it is released as dross on the melt. Of course if you stir sawdust into the melt, the same thing can happen.
Short of buying ready made, there is no free ride.

[mongoose33]

I've switched from corncob and walnut dry tumbling to clean brass to wet stainless steel tumbling. I have a bunch of both corncob and walnut lying around--how would that work? The walnut seems especially appealing as a possibility.

[rockydoc]

I have a BigGreenEgg charcoal cooker so I have a huge supply of hardwood charcoal dust. Sawdust becomes charcoal as it heats up on the alloy, so wouldn't the charcoal do just as well or better than sawdust?

[Seeker]

I answered my own question today. Dried pine needles make exellent fluxing material. I smelted 32lbs. Of pure lead ingots today and 56lbs of coww ingots right after that. The pine needles worked great...and smelled good too.

[scottfire1957]

I have used clean walnut media. It works fine.

[LAGS]

I have a jar of Rosin powder that I use for a non slip agent on my Barrel Vise Blocks.
I think I will try using some of that tomorrow instead of sawdust.
I have a guy that lives two doors down that builds cabinets out of his garage so there is no shortage of availible sawdust. But most of it is not always Pine.
He uses good plywood and hardwoods for what he builds.
You can also find Rosin Powder at sporting goods stores.
They carry it in the small bags that Baseball Batters use on their hands to keep the bat from slipping.
Dont you remember your days in Little League and the old Rosin Bag sitting in the dugout.

[NavyVet1959]

Someone mentioned awhile back something about high temperature steam being a fluxing agent. Not having the capability to inject high temperature steam into my casting pot, I decided to try using a small diameter (about 1/8") green twig from a cypress tree to see what would happen. I was remelting my larger ingots from my smelting pot into smaller ingots that would be more convenient for casting. You have to submerge the twig slowly so that you don't get a surprise from the Tinsel Fairie, but you can hear it the steam coming from the twig and bubbling up. The alloy definitely seemed to change with some things going back into solution apparently. I haven't experimented around with this since then. It was mainly just an experiment to get a data point for knowledge. Maybe someone with a bit more metallurgical knowledge can explain the process that is taking place?

[JSnover]

Someone mentioned awhile back something about high temperature steam being a fluxing agent. Not having the capability to inject high temperature steam into my casting pot, I decided to try using a small diameter (about 1/8") green twig from a cypress tree to see what would happen.
...you can hear it the steam coming from the twig and bubbling up. The alloy definitely seemed to change with some things going back into solution apparently. I haven't experimented around with this since then. It was mainly just an experiment to get a data point for knowledge. Maybe someone with a bit more metallurgical knowledge can explain the process that is taking place?
You were reducing clean lead vs. fluxing scrap and likely would have gotten similar results with dry cypress or most other plant fibers. I don't have the background to discount steam as a reducing agent but I'd bet on the sap, lignin, whatever else is in wood.
For what it's worth, extremely high quality copper was made on the island of Cyprus (among other places) 4,000 years ago by injecting olive oil into the fire. Supposedly this was done to increase the temperature but it also helped clean the batch.

[NavyVet1959]

You were reducing clean lead vs. fluxing scrap and likely would have gotten similar results with dry cypress or most other plant fibers. I don't have the background to discount steam as a reducing agent but I'd bet on the sap, lignin, whatever else is in wood.

I'm not so certain. The results seemed different than if I used a dry twig and while it was going to steam, not much of the rest of the rest of the trig was charring like you would see with a dry twig.

[JSnover]

I'm not so certain. The results seemed different than if I used a dry twig and while it was going to steam, not much of the rest of the rest of the trig was charring like you would see with a dry twig.
That is interesting. I've used some twigs that were still somewhat green and the results were good but the popping was excessive, like having too much grease in a pan of bacon.

[NavyVet1959]

That is interesting. I've used some twigs that were still somewhat green and the results were good but the popping was excessive, like having too much grease in a pan of bacon.

It probably depends upon the type of wood or how green the material might have been. These seemed like fairly fresh spouts, so maybe that made a difference. It sounded like more of a hissing sound as the steam escaped the wood as if it was going through very small openings. Large bubbles were not produced, otherwise I would have quit the experiment very quickly. Of course, I had leather protective gear and a shield between the pot and myself, just in case... :)