Maja, You are aware of the dangers inherent in having and using lead
in your workshop? If not, find out before proceeding any further -
and use common sense. Wash your hands after contacting the block, or
metals that have been worked on it.
Also be aware that traces of lead left on precious metals can cause
you some real problems if you heat the metal up to anneal or solder
There are some procedures for which there just ain't no replacement
for lead, though I've found some of the formulas for lead free
pewter to be soft enough for some purposes.
I assume that you intend to pound something into shape, form it, or
bend it? Whenever you can, cover the block with paper, plastic,
cloth, tape, or foil to reduce the hazards of transference. (Throw
the covering material away after use)
Simplest way I know of to make a lead "cake":
Find some cheap (or free) lead. Ask at a tire dealer, if they will
let you have a few pounds of balance weights. Find a local recycler
or metal scrapyard. Even if you have to buy it, as scrap it is
pretty cheap. A few dollars worth should be plenty.
Then find something to serve as a mold/form. TIn cans of various
sizes work well. One of my favorites is the rectagular sardine can.
Another favorite I picked up at a flea market - A 6" cast iron sauce
pan for $2.00
If you absolutely must have a 6" SQUARE lead block - then I guess
you need to find square cast iron cookware, maybe find a scrapyard
that will cut you a short section of 6" square steel tubing, and
have a welder tack a sheet on for a bottom... that may cost you $30
or more, but you can make as many blocks as you like!
DO YOUR MELTING OUTSIDE! Stay upwind. I DO NOT RECOMMEND THAT ANYONE
PLAY WITH LEAD UNDER ANY CIRCUMSTANCES - IT IS HAZARDOUS IN MANY
WAYS. Always try and find safer substitutes or techniques -
otherwise know your risks.
I use the side burner on our barbeque, since I never use it to cook
on. I melt the lead right in the container it will remain in, or in
the cast iron saucepan. Get a piece of coathanger wire to fish out
the steel clips on the tire weights. Keep adding metal 'till it
reaches the level or thickness that you desire. Use a wooden paint
stirring stick to skim off the dross (scum). It may scorch or catch
fire, but the lead will not stick to it. You can also use sal
ammoniac (plumbers flux) to keep the surface clean and shiny.
It is wiser not to have to pour the stuff, but if you must, pour it
on the ground, over sand. The molten metal behaves quite like
mercury, and runs like water. Doing any pouring at ground level will
minimize splashes. Dispose of the sand and any spillage properly.
If you want to be able to remove the "cake" from the cast iron -
give it a heavy coat of soot before melting. Mine always just fall
out of the pan when cool.
If you must remove a tin can that you have used as a form, you can
usually snip off most of it with tinsnips, sometimes you have to
resort to a sharp cold chisel to cut the side loose.
I use shallow cans, fill them almost to the brim, and when the
surface is too deformed to use - melt a fresh new surface right in the
same tin can.