RotoMetals2RepackboxInline FabricationWideners
MidSouth Shooters SupplyStainLess Steel MediaGraf & Sons

Page 1 of 4 1234 LastLast
Results 1 to 20 of 66

Thread: Lead Adhearing to Mould

  1. #1
    Boolit Master ColColt's Avatar
    Join Date
    Jan 2011
    Location
    South East
    Posts
    2,167

    Lead Adhearing to Mould

    Having a little problem getting rid of a very small piece of lead right at the second drive band on one half of the mould. I tried brushing it off with a cloth while still up to temperature and it didn't work. I tried a toothpick and the same. Being a brass mould I didn't want to try anything sharp for fear of scratching it. Any suggestions as it's leaving a mark on the bullets like there was trash in the mix when it's not, it's coming form this stuck on small piece of lead.

    NRA Patron Member

    Kids Are For People That Can't Have Dogs

  2. #2
    Boolit Grand Master

    Join Date
    Mar 2013
    Location
    Northwest Ohio
    Posts
    9,273
    Wash it with dishsoap and water then with a popcycle stick (Cut it to a square edge at an angle) lightly and gentle work the spot. You may want to warm it up close to temp and try this also. Bamboo skewers from the grocery store are handy to have for this also. Soap water may get between lead and metal loosening it. As a little heat may also break the bond

  3. #3
    Boolit Master
    HeavyMetal's Avatar
    Join Date
    Jan 2008
    Location
    Orange county, Ca.
    Posts
    3,924
    Thyink I'd try a good # 2 pencil with not to sharp a point and a brand new eraser on it!

    Rub with both ends of the pencil and see what happens.

  4. #4
    Boolit Grand Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    5,983
    I would heat the mould to melt the lead... just melt the lead, then wipe out using a cloth or wooden stick as mentioned.

    I see "staining" from lead in that cavity too and I have to wonder why some people seem to get this going on. There is a thread on adding a patina to brass moulds to stop it from happening and I can't figure out how it is happening to begin with.

    I pre-heat my moulds until the sprue plate lube smokes then start casting. The mould is not much below the melting point of lead when oil smokes. Still, I have not had any tinning or lead sticking to my brass or iron moulds.

    Not criticizing, just curious why some people seem to have the problem. Maybe too much tin addition?

    Back to your problem, I would use a thermometer or oil just smoking to make sure the mould is right about lead melting temperature then use a wood stick to scrape that bit out.

    Be careful not to overheat the mould as brass moulds can warp but heating to the temperature of molten lead should not do it any harm and the lead should come out easily then.

    The more I think about it, I wonder if it is tin addition. What alloy are you running? If it doesn't have tin then that obviously isn't it.

    Longbow

  5. #5
    Boolit Master ColColt's Avatar
    Join Date
    Jan 2011
    Location
    South East
    Posts
    2,167
    Nothing seems to work so far. I've tried heating also with a torch, playing the flame back and forth and all around as not to play it too long in that cavity and it still refuses to budge. This is the first of three other brass moulds this has happened with.

    The alloy is from RotoMetals, 1:20.

    The problem it's creating is a small ding on the bullet on the second band, like it's been dropped. It also makes the bullet want to stay in the cavity and hard to release.
    Last edited by ColColt; 09-14-2013 at 10:08 PM.
    NRA Patron Member

    Kids Are For People That Can't Have Dogs

  6. #6
    Boolit Grand Master
    bangerjim's Avatar
    Join Date
    Apr 2013
    Location
    out of here, wandering somewhere in the SW.
    Posts
    8,707
    Well, it looks like you got some compound in there that "tinned" the brass and allowed the lead to stick, just like solder! That could be difficlut to remove. I have not experience with brass molds. Have only aluminum ones. I have always wondered what keeps the lead from "tinning" a spot or two in the cavities of brass molds. That would seem to me not to be a good choice for molds but everybody seems to love them.

    Good luck!

    bangerjim

  7. #7
    Boolit Grand Master
    Join Date
    Aug 2005
    Location
    South Jersey
    Posts
    5,087
    Try white vinegar mixed 50% with hydrogen peroxide
    Regards
    John

  8. #8
    Boolit Master ColColt's Avatar
    Join Date
    Jan 2011
    Location
    South East
    Posts
    2,167
    Tried the vinegar/Peroxide and no dice. It did turn the lead(tin whatever it is) dark so you can see it better.
    NRA Patron Member

    Kids Are For People That Can't Have Dogs

  9. #9
    Boolit Master freebullet's Avatar
    Join Date
    Mar 2013
    Location
    Nebraska
    Posts
    1,481
    As others said-rub yer wood on it.

  10. #10
    Boolit Master ColColt's Avatar
    Join Date
    Jan 2011
    Location
    South East
    Posts
    2,167
    I've been doing that to no avail. It may be there for the long haul. Nothing seems to move it. If I had better eyes and a good magnifying glass I'd try picking it off with an Xacto knife.
    NRA Patron Member

    Kids Are For People That Can't Have Dogs

  11. #11
    Boolit Master
    Join Date
    Jul 2008
    Location
    Paw Paw, Michigan
    Posts
    2,013
    I did this with one of my beloved brass moulds, I was able to remove it by soaking it in kroil for about a week, heating it up then wiping off, popped right off with no issue.
    Good Luck

  12. #12
    Boolit Master ColColt's Avatar
    Join Date
    Jan 2011
    Location
    South East
    Posts
    2,167
    It appears I may need to try that. Nothing else has worked. It's like it's cemented. I don't recall having another mould do this before. But, that's a project for tomorrow.
    NRA Patron Member

    Kids Are For People That Can't Have Dogs

  13. #13
    Moderator



    JonB_in_Glencoe's Avatar
    Join Date
    Mar 2010
    Location
    Land of 10,000 Lakes
    Posts
    10,951
    beeswax

  14. #14
    Boolit Master ColColt's Avatar
    Join Date
    Jan 2011
    Location
    South East
    Posts
    2,167
    Rubbed on and let sit while hot?
    NRA Patron Member

    Kids Are For People That Can't Have Dogs

  15. #15
    Moderator



    JonB_in_Glencoe's Avatar
    Join Date
    Mar 2010
    Location
    Land of 10,000 Lakes
    Posts
    10,951
    I had to search for the thread.
    http://castboolits.gunloads.com/show...ipe&highlight=
    Start at post #8 read through post #13
    AND
    read all the posts to learn about patina
    Good Luck,
    Jon

  16. #16
    Boolit Master ColColt's Avatar
    Join Date
    Jan 2011
    Location
    South East
    Posts
    2,167
    I'll read that and thanks. I've heard of "patina" before but never read about it as it wasn't a concern.
    NRA Patron Member

    Kids Are For People That Can't Have Dogs

  17. #17
    Moderator



    JonB_in_Glencoe's Avatar
    Join Date
    Mar 2010
    Location
    Land of 10,000 Lakes
    Posts
    10,951
    Quote Originally Posted by longbow View Post
    Not criticizing, just curious why some people seem to have the problem. Maybe too much tin addition?
    Yep, Not every brass mold does this. Mostly it's the lack of patina/oxidation on the surface...which I suspect is a factor of the actual Brass alloy, some alloys tarnish/oxidize easier than others, add to that the boolit design [is there lots of points?], then lastly would be the mold temp, and that depends on the alloy temp.

    Brass molds usually beg to be run hot, which also adds to the potential problem.

    I suppose a high tin content alloy may add to the problem, but honestly I'd never used anything higher than 5% and with my 41WC mold that I have posted photos of the tinning problems...that mold has only seen alloys with tin percentages of less than 3%, realistically I'd say 2% or less.
    Jon

  18. #18
    Boolit Grand Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    5,983
    I have to think that your Rotometals 1:20 is to blame for the tinning. Not that there is anything wrong with the alloy, just that there is enough tin to "solder" to the brass.

    I would go with heating to the melting point of lead and scrape off with a wood stick or rub with a cloth.

    Alternately you might try casting very hot with a good mould pre-heat and cast with straight wheelweights for a bit. That may take the build up out.

    I still think though that if you carefully heat until the lead is soft then it will wipe/scrape out. I would use an oven or hot plate not a torch. Maybe once the mould is near the melting temperature for lead a torch to provide that little extra at the glob.

    Once it is out then you may want to try the artificial patina. I have to think that others with this tinning problem are using fairly high tin alloys. I use mostly range scrap and wheelwheights so that may explain why I have no problems with tinning in my brass moulds.

    Longbow

  19. #19
    Boolit Master


    Springfield's Avatar
    Join Date
    May 2005
    Location
    San Jose, California
    Posts
    3,314
    Seems to me if you have heated up the old hot enough to cast with and it still doesn't come out then maybe it isn't lead. I have never had this happen with any of my 12 Mihec brass moulds, but then I always preheat before I cast the first time.
    Last edited by Springfield; 09-17-2013 at 03:43 PM.

  20. #20
    Banned


    Join Date
    Mar 2009
    Location
    29˚6827N, 99˚1207W
    Posts
    14,667
    Springfield is right, it isn't lead, or tin, that's why it won't melt away. It is accumulated oxides of mostly tin, it starts a 'seed' in a shiny spot and just builds and builds a few molecules at a time from the flash-oxidized molten surface of the metal you pour into the cavities. It's the same sort of stubborn crud that clings to the sides of a casting furnace as the alloy level drops. A reducant like beeswax or paraffin quickly takes care of it once you get the mould up to the melt point of the elemental metal.

    Being an oxide, and beeswax being a reducant as JonBinGlencoe pointed out above, you can heat the mould to the point that the tin would start to melt if it weren't oxidized, apply the wax to instantly reduce the oxides to elemental, liquid metal, and wipe them away.

    It happens to me with brass moulds because they do like to be run hot, it IS worse with binary lead/tin alloys, and the brass moulds DO like to be run hotter/faster than other types which DOES exacerbate the oxide accumulation.

    What I do to patina a brass mould for the first session is preheat it to casting temp in a mould oven and let it cool naturally a few times, then smoke the cavities lightly with a BBQ grill lighter before ever putting lead in there. That keeps those little soldered "seeds" from ever starting. After a few casting sessions, I wipe out the soot and leave them alone. This is the only time I ever smoke moulds because it can cause a lot of other problems, but it really helps break-in with brass.

    Gear

Page 1 of 4 1234 LastLast

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