Thars Gold in that thar Dross!

[NVcurmudgeon]

I've been saving lead pot skimmings for months toward an experiment. Having just received a supply of Pat Marlin's World Famous California Flake Flux gave me a good excuse. I had a quart of recovered dross, weighing about five lb. to try refining. I melted enough clean alloy to yield about 5 1/2 RCBS/Lyman one lb. ingots (OK, call it six) in my Potter (ladle) lead pot, followed by some of my skimmings. Then I covered the melt with a thick layer of PMWFCFF, stirred thoroughly, and waited for the flux to mostly burn up. Next I skimmed the pot down to clean metal. It took three repititions to get all the dross processed. After the last processing, I was able to pour NINE of the one lb. ingots! At least three lbs. of good boolit metal had come out of the skimmings. The dross had changed in appearance. Instead of streaks and blobs of metal bonded wth the black dross, the dross contained small irregular lumps of metal. I sifted out the finest the of the dross with a common kitchen strainer and picked through the part that would not pass through the strainer. It was slim pickings, maybe an ounce of lumps that were worth picking out.

Conclusions: I think this process worked to recover most of the wasted metal because the melt was completely covered by the flux. I would never have tried completely covering the melt with my usual candle wax, because of probable huge volumes of smoke. It seems worthwhile to save up skimmings for refining, but it doesn't pay to sift and pick through the dross afterwards.

Yes, I am a mossbacked ladle caster.

[targetshootr]

Velley intellestink. Reckon I'll give it a try.

[randyrat]

Thats a significant amount of good metal pulled out of "thought to be waste dross" Wish i could go to the scrap yard and find all my dross. I would not have thought it was possible.

[sundog]

Dross is NEVER thrown away. It goes into the next big melt. Some of it is pretty nasty looking, but it never seems like there's more of it than any previous time.

[montana_charlie]

You said you were working on 'lead pot skimmings'. I assume that means it came off of clean alloy while you were casting.

If you'd use the 'stick trick' you would never skim it off to start with...
CM

[44woody]

I saved a big coffie can about 3/4 full of skimmings and got about 9 lb of lead back from it I will never throw it away again :castmine: 44Woody

[PatMarlin]

Wow... that's great Bill.. :drinks:

[Ricochet]

I've learned the same thing from experience, that the skimmings are still pretty full of lead, and should go in with the next batch being smelted outside for ingots.

[Cayoot]

I don't even want to think about all the good metal I may have thrown away in the past!

Thanks...I'm gonna save all my skimmings from now on!

[joeb33050]

I get sludgy sometimes colored stuff on top of the pot, then I flux.
I end up with a black to grey powdery dense stuff after fluxing. There's no/little lead looking stuff in it. I can't get that to turn back into lead or ?
Are you guys talking about the sludgy stuff, or about the powder stuff?
joe brennan

[EMC45]

All I get is the powdery stuff too. I use a piece of beeswax about the size of a 000 buck shot pellet in my 10 pound Lee pot. I also flux the same way when going from WWs to ingots.

[buck1]

Bullshop turned me on to this a wile back. Bees wax and sawdust and dont skim untill the dross is light not heavy.

[RU shooter]

You said you were working on 'lead pot skimmings'. I assume that means it came off of clean alloy while you were casting.

If you'd use the 'stick trick' you would never skim it off to start with...
CM What is "stick trick"? I sure would like to never skim top of pot while I'm laddle dipping,It is what fill's my dross can most!

[montana_charlie]

What is "stick trick"?
The stick trick does not eliminate cleaning of the alloy surface. Oxides continually form and must be 'controlled' eventually.

I didn't invent it (actually read about stick fluxing here, about a year ago) but I played with it till I found a method that eliminates taking 'metal' out of the pot.
I only use it on 'clean alloy' while actually dipper casting. 'Smelting' calls for something different, and bottom pouring allows use of a sawdust cover layer.

Instead of wax, or sawdust, or any of the many substances which will 'reduce' oxides, I just stir with a wooden stick. You want to ease it down into the alloy the first time or two you use a new piece of wood, because the alloy will 'sizzle' some when the moisture in the stick gets hot.

From then on, you just use the stick to scrape around on the sides and bottom of the pot (hopefully dislodging any contaminants) and keep herding the surface scum into a glob at one side.
Then mash the scum glob against the side of the pot and shove it down under the surface.
Keep mashing and shoving until nothing floats to the surface but a fine, dark, powder. Spoon out the powder, and discard. There is no metal in it.
(You could even blow it out with low-pressure compressed air, if you didn't care where it landed.)

Whatever the contents of your alloy was when you turned on the pot, it still contains the same ratio of contents after 'fluxing' (reduction of) the scum.

CM

[NVcurmudgeon]

The other day I finally got a chance to use PMWFCFF for fluxing while actually casting boolits. I was casting with mould that has been giving me fits with incomplete fillout. Fortunately it is not my mould! This time I tried keeping the temperature between 725 and 750. (My RCBS thermometer may read low as the bolits were well frosted.) Out of 400 castings there were 350 perfect, 40 very good plinkers, and 10 culls including mould warmers. Using Pat's flux I was able to cast longer between fluxings. Another thing I noticed was that the skimmings were much lighter in weight, with much less visible metal than when using my former candle wax flux. I attribute both of these improvements to Pat's flux. More complete fluxing would accout for the less alloy in the skimmings, and having less dross would keep the surface of the alloy cleaner longer and allow more castings between fluxings. I won't go so far as to say that the new flux was why the formerly persnickety mould tamed down, it may have been the higher temperature. That's what you get when you make two changes at once-guesswork.

[9.3X62AL]

The PWFwhateveritis is a significant casting upgrade for me. I have about 75# of wild wheelweights that need saddle-breaking, and the shavings will be part of the program for sure. I flux like crazy when I smelt, and have usually worked the dross in the pot to the dark gray dusty junk mentioned above. I did get metallic remnants in the smelt previously, which prompted the uberfluxing. I'm hoping the shavings speed that process up.

[BigCheese]

Where can I buy PMWFCFF ?

[NVcurmudgeon]

Big Cheese, go to the "Swappin and Sellin" forum and click on "Pat Marlin's California Flake Flux." Pat made the first post on that thread and you can send him a PM.

[alamogunr]

Was going thru old post this morning to see what I had missed and ran across this thread. About a year ago I smelted about a ton of range scrap. Ended up with two 5 gal buckets of dross and dirt. By the time I finished the last bucket of scrap, I wasn't about to worry about the dross. After reading these posts, I'm sure I threw away 40-50 lbs of recoverable lead. At that time I couldn't care less. I was whipped! I swore off range scrap after that session. If I do any more it will be from our own trap.

As a side note, I picked up two buckets of WW this morning. A young fellow at church that works for a large tire dealer, told me he had some WW for me. Apparently I compete with someone else for their weights since the dealer is big enough to generate many buckets in a very short time. These ought to yield over 80% good ingots since it looks like a greater %'age of the WW are large truck types. Since it is raining this morning, I decided to sort out the trash. Other than the normal rubber stems, it looks to be fairly clean. Amazingly, there are very few cigarette butts. Also, I will probable end up with about 10-15 lbs of stick-on wgts. I have always wondered why the stick on wgts still have the backing paper on the adhesive and look like they have not been used. Does anyone know??

[yeahbub]

A re-post from August:

In my experience, the dross usually contains flaky pale bits and sometimes a pasty grey sludge as well as some dirt/rust/crud. The sludge is the antimony coming out of solution because of a lack of sufficient tin or a high enough temperature. The flaky pale scale is oxidized tin, apparently, with the grey sludge soon to follow as the antimony loses solubility due to tin loss if I have a "borderline" tin poor alloy. Recovered linotype is like that pretty often. To fix it, I throw in a few inches of 95/5 tin/antimony plumbing solder and flux with stearic acid (something I've almost never seen mentioned on casting websites). Stearic acid in the form I get looks like coarse pretzel salt and has a waxy feel to it. It melts and burns like parrafin and nothing sucks the oxygen out of metallic oxides and returns them to a metallic state like stearate. Once it's fluxed and stirred, dirt is the only thing floating on the alloy. I learned the stearate trick from a guy that casts pewter figurines and it works better than anything else I've tried in 20 years or so. Soap makers use it as well, so it's pretty easy to get.

Since I use a bottom pour pot, to prevent continued exposure to oxygen (air) I put a quarter to a half inch or so of clean wood ashes on top of the melt, which also helps insulate and keep temperatures steady. Sprues and rejects go right through it and they don't splash as much. Not much help for the dipper casters, though.


For some good discussion on effective fluxes, protecting the alloy from undue oxidation and what that stuff is that's floating on top here's a group of previous posts: http://castboolits.gunloads.com/showthread.php?t=19204&highlight=yeahbub