Fluxing

[jednorris]

I have a top ladle lead pot. I use beeswax as I was told that paraffin was not as good. I hear people talking about fluxing with pine sawdust, but I was told that the only purpose for that was to retain heat over the top of bottom pours. What does pine sawdust do, and should I try it in a top ladle pot ?.

[dbosman]

Chapter 4 Fluxing the Melt
http://www.lasc.us/Fryxell_Book_Contents.htm
That explains things better and faster than many of us.

When I'm cleaning scrap for ingots I use sawdust and wax. Separately.

[country gent]

I use both wax and sawdust in my ladle pot. I do use them together though. I find the sawdust makes it easier to "see" what Im doing when Im stirring it in. Also the sawdust tends to tame down the flames from the wax some. I really work the lead thru the flux and flux through the lead when fluxing. I use a long handled barbeque spatula and on one stroke push the flux down thru the lead and the up stroke pulls the lead up thru the flux I stir in this manner and scrape the sides of my pot until the flames are gone and the wood chips, sawdust has burnt to ash. I then remove it and cast. On bottom pour pots leaving the layer slows oxidation keeping oxygen away from the surface. Stirring will work but really working the flux and lead together is much better.

[Dan Cash]

The only thing sawdust will do is leave carbon particles in the lead which cause inclusions in the casting. It does flux but adds another impurity. I am ladle casting as well and use canola oil. It has a rather high flash point so a marble size chunk of paraffin will get it burning. The canola will form a solid crust on the surface of the melt which is easily removed.

[Bazoo]

Paraffin fluxes just fine. I use the wife's old wax melts, as well as candles.

I have used sawdust but I really don't like it. I don't think it fluxes as well as wax. I use it when im rendering weights into ingots, I think it helps grab some of the finer particles. But I think it does cause inclusions if used in the casting pot.

I use from a pea sized to a marble sized piece of wax and let it burn then stir. I didn't stir as well as I should have to start with. Then I remove whatever comes up and am ready to cast.

[waksupi]

Just stir it with a dry stick, and forget the wax. The specific gravity of wax will not allow it to completely reach all of the alloy.

[marek313]

I use both some candle wax and stir it with a dry stick and that works for me. Never tried saw dust but that sounds messy.

[indian joe]

I use both some candle wax and stir it with a dry stick and that works for me. Never tried saw dust but that sounds messy.

I thought sawdust sounded crazy when I first read it here - but it seems to work - messy? pends what ya mean by messy - dont get a heap of stinky smoke like with wax - I use sawdust when i first melt up then as I cast just a little dab of wax and a stir (about every fifty or so - single cavity - ladle/dipper)

[yulzari]

A brief note of caution. If you use sawdust ensure it is totally dry. Dropping damp sawdust into molten lead is NOT a good thing.

[yeahbub]

The most effective fluxing agent I ever used is stearic acid mixed 1:1 with paraffin to improve dwell time as it burns off and stirring the alloy while it does. Metallic oxides on top of the alloy immediately go back into solution in the alloy and all that should be on top of the melt is a bit of dust and dirt. The transformation is very fast. Don't skim off the crusty grey-brown dross. There's money in it in the form of tin oxide mostly. If there's a pasty silver-grey sludge on top with it, that's the antimony coming out of solution for lack of tin. Effective fluxing returns the tin oxide to metallic tin and the antimony will go back into solution in the alloy. I had this problem when casting with used up type metal. The typesetters would cast type with it until the tin was oxided out and it wouldn't cast good type anymore, then it was off to the scrapyard. By the time we get it, it's tin-poor and the antimony starts to come out of solution and float to the top. Back in the day, candles had some degree of stearate in them, either from tallow or vegetable sources and were effective at fluxing. Paraffin by itself isn't effective in my experience. Sawdust seems to be indifferent in it's effectiveness, but the ashes are useful for protecting the alloy from contact with atmospheric oxygen and reduces the need for repeated fluxing.

[TNsailorman]

I bought some sawdust/shavings to try on this forum and I did not like it. Build up of crud all over the side of my Lee pot. Took some elbow grease to get it off too. Maybe I did not know how to use it correctly but it is not for me. james

[BrentD]

Ihave used sawdust but worry about stirring it deep in the pot due to the moisture issue. Even if "dry", during summer and humid conditions, it absorbs a fair bit of moisture and I can feel it boil when I hold it under the surface of hot lead.

For that reason, I use bullet lube - after all, it's not good for much else as a paper patcher.

I did, however, actually get kicked off of Cast Boolits for saying that bullet lube works pretty well as a casting flux. REALLY, so be careful where you say that. I couple highly placed people take serious offense. Hopefully, they don't visit the BPCR portion of the site.

[Chill Wills]

I would recommend having their oxides analyzed before telling everyone what alloy constituents they (for sure) are. Just saying!
You might be surprised that the often repeated internet lore turns out to be less simple.

I hope I have not stirred the lead pot too much

[semtav]

I had a candle once that actually seemed to dissolve the oxidized stuff back into the pot, but still made a stink of the place.
Most of them don't seem to do that good.
The "flux" I first bought when I started, seems to work as good as anything. Buck Beavers Lead Reloaders Flux. Altho I don't really think it is fluxing but tying up the oxidized lead in its powder.
Other than using that once in a while, I just skim the oxidized lead off the top and throw it away. that way I don't have to care what it really is.

[rcslotcar]

I like to use both. I start my flux with paraffin, then go to wood shavings. I let the wood shavings sit on top till they start to blacken (to make sure there is no moisture) then lite it on fire. When it burns out I then mix it in. I'll then let the ash sit on top to keep the mix even and not separate. I also have a pot cover made from aluminum.

[BrentD]

I like to use both. I start my flux with paraffin, then go to wood shavings. I let the wood shavings sit on top till they start to blacken (to make sure there is no moisture) then lite it on fire. When it burns out I then mix it in. I'll then let the ash sit on top to keep the mix even and not separate. I also have a pot cover made from aluminum.

This and many other things makes me think that really all you need is some powdered or ground charcoal. In the end, all of these materials are hydrocarbons that get charred to more or less pure carbon.

[Chill Wills]

other than using that once in a while, i just skim the oxidized lead off the top and throw it away. That way i don't have to care what it really is.

bingo

[waksupi]

Ihave used sawdust but worry about stirring it deep in the pot due to the moisture issue. Even if "dry", during summer and humid conditions, it absorbs a fair bit of moisture and I can feel it boil when I hold it under the surface of hot lead.

For that reason, I use bullet lube - after all, it's not good for much else as a paper patcher.

I did, however, actually get kicked off of Cast Boolits for saying that bullet lube works pretty well as a casting flux. REALLY, so be careful where you say that. I couple highly placed people take serious offense. Hopefully, they don't visit the BPCR portion of the site.

If you were kicked off Cast Boolits, you wouldn't be here now.

[BrentD]

If you were kicked off Cast Boolits, you wouldn't be here now.

What can I say. I was and then was permitted to return. True story. Pretty much sucked.

[bmortell]

what I do is take sawdust and spread it in a thin layer on a flat surface, melt wax in a pot, pour evenly over the sawdust so it entraps all the sawdust in a sheet kinda like a thin nobake cookie, cool and break it up into pieces and put it all in a cup. and you got premade little flux cookies, YAY

for fluxing itself I toss some bits in, light it on fire, spoon stir while its on fire until it goes out. then I gather everything that's floating togather on the spoon and feel its fluffy light ashes then take it out, if it still feels metal like as in some weight to it and mushy repeat step one.