Rendering dross

[Bookworm]

I melted down and cleaned (rendered) some sheet lead today, ended up with ~80 pounds of ingots. This lead must be very close to pure, even the ingots have a purplish tinge to them.
When I render dirty lead, I dump the dross in a coffee can. When cool, I sieve the dross, to get the dust/sand/dirt size junk out (this gets put in the garbage bin), and toss the remainder into another can.
Today I noticed that the sieved dross can was full, so I rendered it too. I ended up with ~8 pounds of dross-ingots.

Now the question - what to do with it ? This is dross from multiple sources - range-lead, COWW, SOWW, plumbing pipe.

As of now, I have it stacked with the range-lead, and thought I would use it the same as range-lead. Mix it in with COWW in the same ratio as range-lead.
Comments ? Suggestions ?

[markcmccoy]

Need to follow this thread. I have a bunch of dross that I have yet to find a home for

Sent from my Nexus 6 using Tapatalk

[pjames32]

I think it is mostly tin. I MAY BE WRONG! I throw it in with my clip on wheel weights when I render them. I have a couple 3lb coffee cans saved.
PJ

[John Boy]

Comments ? Suggestions ?
Buy a lead tester. Then you have a hardness starting point for your new alloy

[scottfire1957]

I think it is mostly tin. I MAY BE WRONG! I throw it in with my clip on wheel weights when I render them. I have a couple 3lb coffee cans saved.
PJ


Yep. Just toss it into the next big batch.

[Chill Wills]

I think it is mostly tin. I MAY BE WRONG! I throw it in with my clip on wheel weights when I render them. I have a couple 3lb coffee cans saved.
PJ

I hate to sound like a contrarian. My curiosity prompted me to the following.

I have done this same thing and keep storing the skim from my casting pots in a bread pan. Once my bread pan is full I render it with a lot of sawdust. I always get 6-8-lbs of clean metal.
After years of this and never using it because I was unsure of its content I had the opportunity to have it tested. Long story short, I had made a shooting friend whos brother is employed at Cummings Diesel. He had access to good testing equipment. They had my samples tested.
Regardless of what I was casting and the different alloy source of dross going into the pot, the reclaimed metal was averaging 2.29SN, 0.38 Sb The remainder Pb with a fraction of a 1/10 percent being all other.

This is an average of many dross pans and the individual test showed some small variation. All kinds of metal went into the casting pots. Pot temp is held between 700F and 775 max.

My conclusions:

Pb and Sn oxidize out somewhat in proportion to their ratio in the alloy
Maybe Sb does not oxidize much below 800f ( or 1100F for that mater)

I guess I don't really buy into the idea you can skim off ALL your tin form the lead. I do think that you can overheat alloy and over time change the makeup. As in printers Lino needing to be refreshed.

This subject seams to be a long running fight for some people so this is the extent I want to get into it.
One way or another, it changes what I do casting only so much.
:drinks: Carry on - Pour some more. :smile:

[Nose Dive]

Hmmm.. DROSS... yep...I get alot.... But,,my smelt is really 'trash and grud' taken from ...well...anywhere....

I do resmelt it. I get about 20 lbs or so and dump 2 scoops of sawdust and one of elemental sulfur from the nursery, add the dross...and get after it. SMOKE...STINK...MIX WELL and scrap out corruption... I add wax at the last and mix well. Scrape sides and bottom of pot...

So...what's left is made into cupcake ingots and marked...dross ingots. Since I have alot of 'bad ingots'..made from garbarge... I have alot to resmelt and this is when I add 50/50 dross ingots to my 'bad' ingots and follow the same procedure. Yes I use alot of sawdust and sulfur...but I make the sawdust with my table saw and am getting $8 bags of sulfur from the nursery for $2 abag as it has been rained on and now a block in a bag. No difference to me. I finish these 'dross' smelt cuts with wax from anywhere I can get it. Church lady brought me some. Got 50 or wax toilet rings from a demo'd apartment complex. Yep...wax is wax. I do alot of range scrap so, end up with a lot of 'dross'. So, key to me here is to keep temp down at 700 or so and keep copper from melting...

So, in my opinion...save your dross...resmelt it...use it.

Nose Dive
Cheap, Fast, Good. Kindly pick two.

[Bookworm]

Well. If the dross does have tin content, I may move it over to the COWW pile, and use it as such. I have some of the pencils, for testing hardness. I suppose I should get off the pot and just try doing it.

I started reloading in the late 1980's, but have only been on the casting game for a year or so. So far, I have been mixing range lead and COWW at 50/50, shooting from various handguns, with good success.
I have not yet stretched the velocity envelope with the 44 Mags, or the .357s, but that too shall come to pass. There are so many variables to explore in this section of the hobby. Then there is the 44Mag rifle, and the 357 Handi-rifle....

I am fortunate to have a short firing range out behind the barn, I can just walk down there any time.

[runfiverun]

throw it in with the range lead.

[Chill Wills]

throw it in with the range lead.
I think that is good advice and the easiest thing to do for most people.

My local range lead is long on tin. I put on the BPCR match and repair the berms. Most of the lead is available is in the form of large lead/tin alloy bullets. I do not want to add any more of this dross metal to it because it works too well as is. It is easy to get and I have more then enough.

I have not done anything with my recovered dross alloy but I do store it together. Really have been in no hurry. There is 50-75 lbs of reclaimed alloy with 2+% tin that will go into something at some point. Just not sure what yet.

[Mitch]

I to save skimmed stuff off my casting pot but not from the smelting pot.what little I get a just throw in with a big batch of pistol alloy.i have not had any tested but it allways seems to scratch easy so I realy don't think it has much of anything in it.And realy for what it takes to clean up and get a few lbs of lead not worth it.if it realy were hi tin content it would not scratch with the thumb nail.So realy it is only rangelead or scrap lead nothing more.as for the stuff off the smelting pot a belive it is mostly oxidized PB.think about it this way you pot in this case has a lot more surface area to be exposed to the air.

[GhostHawk]

I have always saved my dross. Once a year I like to melt down some soft lead, some range lead, add a little tin. Normally I do this with ingots that are too large for my pot. Cast them into the lyman 1 lb ingot.

I always start my pot by melting down the dross first then add ingots, big blocks, big downrigger cannonballs, old plumbers lead ingots, etc.

My method is rather simple. I pour the first ingot, cool it in water and scratch it with my thumbnail.

Pure soft lead leaves a gouge with raised sides. Lead that is just about perfect for pistol and low pressure rifle leaves a shiny spot but no gouge or sides.

Once I am happy I cast it all to ingots stack them around my pot and call it good.

[MrWolf]

I smelt using a cutoff propane tank. Gets dumped into the next batch.

[John Boy]

So, in my opinion...save your dross...resmelt it...use it. Hold it! A properly fluxed alloy will only have ASH, gray ash. There will be no metal of any kind in it. If there is - you are not fluxing the alloy properly regardless if it is from smelting scrap lead or the melt in the pot!

[Chill Wills]

Yes, BUT, for the little we are talking about my time is much better used doing things that result in more than a 1/2 oz lead each time I turn on the casting pot or reduce a batch of range scrap.

I don't care enough to do it bit by bit. I just save it all until I have a large amount. A much better use of my time.

[Oklahoma Rebel]

hi guys, I know there shouldn't be any metal, only dust, but here lately I have had metal in my dross. I use cedar sawdust, and sometimes wax. with the cedar the metal kinda balls up in the ash. don't know what to do, but I smelted some dross and it sounds like it definetly has tin in it, has a ring to it. any help would be appreciated. what temp do you add your flux at?

[Oklahoma Rebel]

I just did quite a bit today, ended up with a 20+lb block, I did add a couple muffin ingots to get a puddle started in the bottom, about 3lbs, I kept the flame up high and kept the pot covered , when it got pretty hot I added a good handful of paraffin based lube that I rejected and saved for this. I did end up with about 3 inches or brown and blackish dust on top, I scooped it off, then when close to the lead I used a small screen mesh like you use in cooking,to get the rest of the **** out. I did leave a little dust in there, it is impossible to get it all. ok good luck!

[Oklahoma Rebel]

it has a good ring to it so I know it has at least maybe 3%tin but I am wondering how much sb is there.... I guess I wont use it until I need to send something out for testing, then I will send a sample of this as well. when I find out I will let you guys know. It's gonna be a while before I do this again, it was a pain to get it all to melt and worse cleaning all the dust and clips left in it.

[RogerDat]

Dross alloy somewhat depends on lots of factors, will be more tin in dross from melting pewter than in smelting range lead. I crush the ash against the side of my cast iron or stainless steel pots, it sort of helps get the BB's of metal out, but never 100% clean ash when I scoop it out.

I have done a fair amount of printers lead, and pewter, along with some large batches of Lyman #2 so I find my dross is fairly rich. Bunches of WW's the yield is not so rich.

I just feed the stuff back into large batches. Figure an 8# chunk won't impact a 120# batch much and I generally just guess on the low side based on what the dross is from. Bunch of WW's & Plain then dross is added as "plain" All WW's dross is WW's. Mostly Lyman #2 call it WW + 1% Sn.

Lately I have just been stacking the dross in slabs from bread loaf pan, when I get enough I'll probably mix it all in one batch and have it tested. Just easier to use already "known" stuff and let the dross accumulate until enough there that testing the allows it to be used in a batch accurately.

[Oklahoma Rebel]

I left mine as a 2" thick plate out of the bottom of a propane can, it literally rings like a bell, so I think its pretty rich in tin

[Oklahoma Rebel]

ok, I took about 1 oz of this block, just clipped off the edge, put it in a lyman dipper, and used a torch to heat it up. the tip of the thermometer was resting on the bottom of the dipper, if that makes a difference, but it melted ( the alloy) at about 480,i printed a page from here I think with different melt temps, and it seems to suggest that what I have is VERY tin rich, run five or anyone else, do you agree or have any other thoughts? I am hoping it is mostly tin because I have been making some 20:1 and would like to make a big batch, I have about 80lbs of 4.1sn to 1.9sb that I will use, the sb will get watered down enough that it wont really matter,as far as making it brittle. so let me know what you guys think.

[Grmps]

Hold it! A properly fluxed alloy will only have ASH, gray ash. There will be no metal of any kind in it. If there is - you are not fluxing the alloy properly regardless if it is from smelting scrap lead or the melt in the pot!

I concur. I don't claim to be an expert,... my experience 50# dirty/mystery lead , 2 tbs sulfur (in case of zinc) stir - stir- stir with an Asian spider strainer then flux with small handful of sawdust , burned off - stir - stir - stir ( the spider strainer does a good job getting the flux into the lead) then repeat with the sawdust - burning and stiring that leaves "ash" and the crud that was stuck to the lead, NO DROSS

[Oklahoma Rebel]

bump!

[runfiverun]

Travis there are a few things that can lower an alloys melt temperature.
clip on ww's will melt at about 500-f.
think about that for just a second.
yep antimony will allow the alloy to melt at a lower temp. [weird huh?]
but so will bismuth.
and so will Tin. [melts at @ 450-f]

but if your below 500 you got something with a higher tin content [lino-type melts at about that 480 point]

[RogerDat]

Well I had three bread loaf pans of assorted dross, cleaned up splatter, some reject bullets, some bottom of the pot residue and a partridge in a pear tree.

Yield was 10# ingot of what feels and looks like decent alloy and 1 full loaf pan of dust. I was noticing as I labeled it and put it on my misc. shelf that I had slabs marked "smelting dross" and "casting & alloy dross". Smelting will be mostly plain or COWW's, with a touch of maybe dental foil or cable cover. Big pots of basic stuff. The alloy and casting will mostly be richer stuff. At least based on grain structure and general hardness (ring vs. thunk too)

[Oklahoma Rebel]

so run, your saying it is rich in something,lol thanks very helpful!