Graf & SonsMidSouth Shooters SupplyRotoMetals2Lee Precision
Titan ReloadingBallisti-CastInline FabricationStainLess Steel Media
Page 1 of 2 12 LastLast
Results 1 to 20 of 29

Thread: overheating lead when melting scrap

  1. #1
    Boolit Mold
    Join Date
    Nov 2006
    Posts
    15

    overheating lead when melting scrap

    just started using a johnson furnace today and i think i might have ruined a batch of dental lead, I melted the lead and tried to flux and it was like stiring very hot dirt, may have been over 1000 degrees, i shut it down and will try again today after some suggestions, I am afraid to smelt my wheelweights as i dont want to ruin them any help appreciated, thanks

  2. #2
    Boolit Master Wal''s Avatar
    Join Date
    Mar 2012
    Location
    High Country, Australia
    Posts
    788
    If it was feeling like stirring hot dirt...................seems to me theres something else in there that shouldnt be.


    "Think for yourselves and let others enjoy the privilege to do so too."

  3. #3
    Getting the lead that hot won't ruin it. Speculating on the temp can get you chasing your tail, and it doesn't really matter in this case. Either there's something else in the pot, that should have floated to the top. Or it's more lead than you are used to and it's just heavy to stir. I'd get it melted, use the thermometer just so the temp is known, and see what's in there by pouring your ingots and draining the lead. Assuming you have tried to dip out some of the "dirt like" alloy to see how if there's anything there.
    Rossi M92 Lever Action
    Taurus 669
    Kel-Tec P-3AT
    http://357shooter.blogspot.com/

  4. #4
    Boolit Mold
    Join Date
    Nov 2006
    Posts
    15
    Thanks for replying, the lead looked like hot ashes all the way through, or it looked like the dirt you skim off the top except the dirt was 6 inches thick and my dipper kept comming out with yellow dust on it I was wondering if when it hits a certain temperature that it changes to a powder

  5. #5
    Boolit Master




    Join Date
    Feb 2009
    Location
    southeastern PA
    Posts
    2,658
    Sounds like you definately had something else in that lead. Try turning down your burner as soon as the mix melts thoroughly. Apply just enough heat to keep it liquid. Might help. enjoy Mike
    I have about 20 lbs of dental foils to melt - hope mine doesn't go nuts like yours.
    Politicians are a lot like diapers. They should be changed frequently, and for the same reason. Benjamin Franklin

  6. #6
    Boolit Master
    mdi's Avatar
    Join Date
    Jun 2008
    Location
    So. Orygun
    Posts
    3,243
    Most of the dental foils I get have a sticky side, mebbe to attach the foil to a guard/holder? May have something to do withit, but yellow "dirt" doesn't sound good. If you can adjust your furnace to where the lead just melts, watch it and stop when the melt just turns liquid. Mebbe different results. Otherwise it sounds like your lead is contaminated (or mebbe the dentist is using sumpin' besides lead?).
    My Anchor is holding fast!

  7. #7
    Boolit Master
    Join Date
    Jun 2008
    Posts
    1,281
    Before I wised-up and got a thermometer, after skimming out any zinc or steel weights, I would set my lead rendering pot to a heat level the just allowed bees wax to flash ignite, then turn it down to where it just barely does not self ignite. That was probably around 800 degrees. I would hold it there at that heat level for almost an hour to be sure the whole batch was thoroughly heated and then flux the beejeebers out of it until no more dirt or ash would rise with vigorous stirring and folding. Your oatmeal-like batch may be zinc contaminated.

    prs

  8. #8
    Boolit Master 40Super's Avatar
    Join Date
    Dec 2011
    Location
    1/2mile from nowhere
    Posts
    758
    I found some exray sheets and they were nothing but lead impregnated rubber'ish. I would've been lucky to get 5 lbs lead out of 50 lbs sheeting. Not much lead in certain types.
    sent via hammer and chisel

    need oversized powder funnels , PTX's or expanders ? just ask, I make 'em for most brands plus my own styles.

  9. #9
    Boolit Mold
    Join Date
    Nov 2006
    Posts
    15
    looked at the cooled down batch this morning, there is about 30 lbs lead that cooled in the pot and there is 3/4 to 1 inch deep yellow dust on top of it. any ideas, and i know the temp was over 1000 when i turned off 2 of the 3 burners thanks

  10. #10
    Boolit Mold
    Join Date
    Nov 2006
    Posts
    15
    I packed the pieces into the pot and then fired up the 3 burners, as it melted i kept adding the foil to the pot when it all melted i threw in a chunk of beeswax about the size of a heaping tablespoon, i than started stirring, there must have been about 30 to 40 lbs of lead, it was like looking into molten ash, or glowing dirt, so i gave up and shut down the pot, looked at it today and you can see about 3/4 inch or more of yellow dust on top of the cool lead

  11. #11
    Boolit Master



    cbrick's Avatar
    Join Date
    Dec 2005
    Location
    Kalifornia Escapee
    Posts
    8,991
    What you experienced with the dental foils isn't anything I've experienced but it sounds very much like those foils aren't the percentage of lead that perhaps you thought, just has to be a bunch of something in them that isn't lead.

    I suggest you get a thermometer and with a clean pot go ahead and melt your WW but do so at no more than 700 degrees. Anything that floats at that temp is likely zinc, skim it out before it melts. I'd bet you experience completely different results from your experience with the dental . . . stuff.

    Rick
    "The people never give up their freedom . . . Except under some delusion." Edmund Burke

    "Let us remember that if we suffer tamely a lawless attack on our liberty, we encourage it." Samuel Adams

    NRA Benefactor Life Member
    CRPA Life Member

  12. #12
    Boolit Master 40Super's Avatar
    Join Date
    Dec 2011
    Location
    1/2mile from nowhere
    Posts
    758
    Skim off the yellow ash and throw away. It must be the dross of whatever junk is mixed in with the foil. Reflux after skimming to make sure everythings out, then pour into ingots.
    sent via hammer and chisel

    need oversized powder funnels , PTX's or expanders ? just ask, I make 'em for most brands plus my own styles.

  13. #13
    Boolit Mold
    Join Date
    Nov 2006
    Posts
    15
    Thanks, I am going to try again tommorrow

  14. #14
    Boolit Master nonferrous's Avatar
    Join Date
    Jul 2009
    Location
    Southwest Florida
    Posts
    233
    Sounds a lot like the mess you get when you smelt stick on W-W's. All the glue and foam backing go to the top, make a thick glop and need a lot of skimming.

  15. #15
    Boolit Master
    Join Date
    Nov 2010
    Posts
    184
    if you got zinc send it to me

  16. #16
    Boolit Master Bullwolf's Avatar
    Join Date
    Apr 2011
    Location
    California/Nevada border
    Posts
    596
    I have melted down a few small batches of lead dental X-ray films.

    I "believe" that the X-ray film backings that I get are coated with some kind of plastic. I get a fair amount of ash in the pot from them, even before fluxing when I melt them down. The X-ray films are very thin and fluffy and really take up a lot of bulk.

    Despite the extra amount of fine powdery ash, the backing films still melt into a usable lead alloy, just like wheel weights. I typically gather all the dust off the top with an old casting spoon or ladle, then put it in a empty soup can. When I'm all done, I will often go back and re-heat the powdery dross again to see if there was any missed lead in it. This extra step is often not worth the effort, but it makes me feel thrifty.

    I smelt the lead X-ray backing films into ingots, much the same as I would wheel weights. I flux the melt with sawdust, and paraffin, and stir vigorously with a dry hardwood stick. Then skim off the dross until I get a clean looking alloy that is very similar to WW lead, and then pour it into ingot molds. I used to mark the top of the ingots with a permanent marker, but I have had it wear off and become hard to distinguish over time. I also kept using up marking pens. Now I simply scribe - X-ray Films - into the top of my ingots, with a metal punch. This way I don't find any mystery alloy lead ingots later on, and wonder what they were made of.

    So far I have found no downside to using free dental X-ray film backings other than them having a bit more dross to skim off. I am sad that they are slowly disappearing, as more and more dentists move to digital X-rays. Fortunately I do some work on the side for my old fashioned dentist who still uses them, and is willing to save them for me.


    This small batch sure looked like a lot more than 16lbs of lead, but free is free.


    Melting down the X-ray films, then fluxing. Stir with a dry hardwood stick.


    Mini-ingots for my small hand held electric pot, rusty muffin pan drops nicely.


    All done, next to bottom of the pot ingots. Not a lot this time, but it adds up.


    - Bullwolf

  17. #17
    Boolit Master

    Beau Cassidy's Avatar
    Join Date
    Mar 2005
    Location
    Nashvegas, TN
    Posts
    1,071
    What bullwoof said. One of the first things I would do is flux with sawdust. I think you will get better results by doing that. Another good- actually really good- flux is the one from NEI. It brings stuff to the top other fluxes don't.
    At one with the gun.


    http://www.jeffhead.com/liberty/flagdistress.htm

    Pending Molds...

    MiHec 429244 Cramer HP http://castboolits.gunloads.com/show...9244-Cramer-HP Patiently waiting.....
    MiHec 375 H&H GC HP
    MiHec 10mm/40 4 Cavity Brass HP

  18. #18
    Boolit Mold
    Join Date
    Jan 2013
    Posts
    3
    I just did this too. I had a bunch of wheel weights that I melted into my Lee Pro 4-20. I did the original melt a week ago and had about 1/2 of the pot full of cold mix. I put a lid on it to speed the melt and cranked it up to the max setting. I left it alone for about 15 minutes or so. When I came back, the whole mix was glowing a medium red like when you turn an electric range burner on High. I have a digital pyrometer with an Iconel thermocouple capable of safely measuring up to 2000F. I stuck the thermocouple in and it broke through a hard crust into the melt underneath. The temperature was 1437 degrees. After getting over my astonishment of the prowess of the little electric melter, I started trying to get it to remelt by stirring with a stick of pine. The wood ignited immediately as expected, but the hard crust just kept breaking up and floating. I scooped it out and dumped it into a steel cup and now it appears to be a brownish orange color like dirt with some clay in it. Two questions, 1) what is this crusty stuff? 2)did I screw up my boolit alloy? How can I test the lead remaining? (Ok 3 questions). I appreciate any insight especially from you chemistry types.

  19. #19
    Boolit Master

    Beagle333's Avatar
    Join Date
    Mar 2012
    Location
    Back in the woods a piece, just outside Auburn, AL.
    Posts
    2,364
    Now that is a good Lee 4-20! Mine won't get that hot.... but I do get the yellow-orange powder on top of my alloy, along with what looks like beach sand. I'm using isotope lead that I bought and so I don't know what he fluxed with.... but I'll get a teaspoon of what looks like sand and yellow dust off the top of the pot with every 3lb ingot I melt.

  20. #20
    Boolit Master 40Super's Avatar
    Join Date
    Dec 2011
    Location
    1/2mile from nowhere
    Posts
    758
    Yellow powder sound like sulfur ?????

    My 4-20 pot will get awfully hot also, (it's the 220v model). With the dial on 4.5-5.0 it'll be 750-800F.
    sent via hammer and chisel

    need oversized powder funnels , PTX's or expanders ? just ask, I make 'em for most brands plus my own styles.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check