Re: Hardened Lead Balls

Plus metal is used to restore tin content, not antimony. It is no
richer in antimony than linotype metal, but is richer in tin. When we
ran linotypes we would flux the remelt pot and skim off the dross. The
dross was then weighed, and a like weight of plus metal was added to
the melt before casting it into Margach ingots. This restored any tin
content lost in the course of casting, remelting, and fluxing. It is
tin, not antimony, that is the crucial element in typecasting, because
proper tin content is essential to getting a sharp cast that fills out
the matrix and gives 'good face.'

Monotype metal properly so called is almost non-existent in the U.S.
The people I knew who ran monotype machines used the same metal in
them as they did in their linotypes. It may have been back in the days
when actual print runs were done with monotype formes that the harder
monotype metal was preferable, but by the late '50s, just about all
monotype work was used either for electrotyping or reproduction
proofing. Wear properties were not important in these applications,
and lino metal gave just as good a cast.

Foundry type can usually be told by the presence of a founder's mark
on the side of the piece of type. If you have individual pieces of
type that do not bear such a mark it is probably cast on a monotype
machine or Thompson caster, and God knows what kind of metal it is.

Brinnell hardness testers can be bought from handloading suppliers.
Check Midway Shooting Supplies or Huntington Die Service. Both have
online catalogues.


On Nov 24, 12:12 pm, LBussy <lbu...@xxxxxxxxx> wrote:
On Nov 24, 2:24 am, Richard J Kinch <ki...@xxxxxxxxxxx> wrote:

Lead does not harden.  Whoever says that is ignorant of basic metallurgy.

Hrm ... as are you apparently.  Lead is hardened the same was as any
metal, by alloying and manipulating the crystalline structure through
heating and cooling.

Lead is alloyed with tin and antimony to improve the castability
(tin), lower the melting temperature (tin and antimony) - also known
as creating an eutectic mixture, and to harden the product
(antimony).  A cast piece may also be quenched to achieve a higher
degree of hardness.  Folks that are serious about casting their own
bullets have done the leg-work[1] and determined that quenching and
sometimes heat-treatment cycles improves the hardness of the cast
product.  Wheel weights are a crapshoot as far as alloying goes; they
can be and often are just about any hrdness with varying percentages
of tin and antimony[2].  They can certainly be used as grinding media,
but chances are they won't last as long as a harder allow with more
antimony (such as linotype or monotype).

I recently spent a number of hours casting my own lead balls from
linotype obtained from a gentleman who was well acquainted with the
maintenance of his alloys.  He had them regularly tested and used plus-
metal (a high concentration of antimony to lead, used to add back
metals lost through oxidation in the melting/casting process) to keep
them where they should be.  The resultant balls were hard (could not
scratch with a nail at all) and shiny, like a ball bearing almost;
HUGE difference from soft lead.

Did I need to go through all that trouble and spend extra money?  No,
but it makes me feel better.

-Lee

[1] Stronger bullets with less alloying, by Dennis Marshall, The NRA
Cast Bullet Book by Col. E. H. Harrison, page 119 & 121; Heat Treating
Lead, Antimony, Arsenic Alloys, by Rick Kelter,  Heat Treating Lead -
Antimony - Arsenic Alloys.
[2] The Truth About Wheel Weights, by Dennis Marshall, The NRA Cast
Bullet Book by Col. E. H. Harrison, page 133.

.

Relevant Pages

  • Re: Hardened Lead Balls
    ... "Pot Metal" alloys were made of numerous metals: zinc, lead, copper, tin, magnesium, aluminum, iron, tin, and cadmium, among others. ... Lead is alloyed with tin and antimony to improve the castability ... maintenance of his alloys. ...
    (rec.pyrotechnics)
  • Re: Leadddd
    ... harder and contains more antimony and a little bit more tin. ... Old linotype slugs were routinely remelted, but in a properly managed operation, ... to the top of the melt, along with some oxides of the metals in the alloy. ... Relief printing from wood blocks was known in China long before it ...
    (rec.pyrotechnics)
  • Re: Microsegregation question
    ... Your requirement for ferrous metals is common, ... imply that the added hardeners (antimony, copper) accumulated in the ... grain boundaries in some relation to each other... ...
    (sci.engr.metallurgy)
  • Re: Microsegregation question
    ... copper) in specific grain boundaries? ... could antimony accumulate in the grain ... softer metals are often cut on a lathe or milling machine to prevent ...
    (sci.engr.metallurgy)
  • Re: White Metal - TinLead - Where to get?
    ... I asked about tin \ lead as I want something easy to practice with. ... myself moving to whatever metals I can work at home and are good at ... Pete, you may need to research the painting of lead figures. ... I think a company called Alex Tiranti used to sell the equipment and materials for all manner of casting, including polyurethane mixes to make moulds for whitemetal casting, to professional users, don't know if they are still trading. ...
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