I had crossposted the initial question to the hobbicast @
yahoogroups forum. Here is Doug Allen’s reply of how he does it,
which I found quite informative:
As a knifemaker, blacksmith, and, yes, hobbycaster, I have
fiddled a bit with steel casting. It is quite possible to do,
even on a small scale, but you'll have a few more isues to deal
with compared with the more usual aluminum and brass casting.
First off, you'll need to figure out what kind of steel to
use. There are literally thousands, ranging from sible low
carbon plain steels, almost purely iron with only a few trace
elements to high-speed complex alloys, where iron plays second
fiddle to vanadium, chromium, cobolt, and other exotics.
I cast a simple stainless steel, 304 I believe, for a guard,
but I have also done a bit of wootz experementation (wootz is a
high-carbon semi-cast steel that has pronounced carbon
dentricles which make a wonderfu "watered silk" pattern in the
final pie) and have studied enough ferrous metalurgy that I
feel comfortable expanding beyond what I've actually done.
Iron has a great afinity for carbon, and the more carbon there
in in a steel, vice other alloying agents, the lower the
melting temperature. Hence, cast iron is easier to ast than
pure iron, as it is several hundred degrees lower in
temperature when poured -- hence the popularity to this day for
cast iron of around 3-4% carbon. Most high carbon steel, such
as used for knives, is around 1%, and most low carbon is
around .1% (think car bodies and other sheet steels that will
be deeply deformed during fabrication).
One aspect of this carbon affinity is that the longer it sits
in contact with carbon, such as a clay-graphite crucible, the
more carbon it will dissolve out, both changing the carbon
content and lowering the temperature of the melt. But carbon
can also be burned out, so if you leave it exposed while molten
to an oxidizing atmosphere, you'll end up with carbon loss.
So, first you'll need a setup that can get your melt
relatively quickly to the pour temperature, while keeping the
steel away from atmosphere. For this, I used a small silicon
carbide crucible with my steel stacked inside, along with some
borax as a flux, and the whole thing sealed with a bit of
kaowool and furnace cement, with a small hole (about 1 mm) left
to prevent gas build up. To get it hot, I used a propane
forge, blown, which I sealed up except for a small exit vent.
This is similar to what I used for my wootz experements, and
which I've seen other smiths use for various steel castings and
wootz ingot melts.
To cast, I used an oil-bonded sand mold (commercial petrobond
from our Sponsor) with plenty of sprue, venting, and so on --
molten steel is incandescantly ho, and the oil bonded sand does
produce a bit of smoke and outgassing. In fact, if I were to do
steel casting in any quantity, I'd go with ceramic shell or
greensand (bentonite based)to avoid the whole smoke and stink
Even in thermonuclear toaster such as my forge it takes a
while to melt. I had about a pound of steel, and iirc it took a
good couple of hours before it just sloshed when shook -- for
quite a while I could hear/feel a lump of something floating in
When you open the crucible, be prepared for sparks. Even with
the low-carbon there was quite the sparkler effect when
pouring, and at a demo where we had a crucible break during a
wootz smelt it looked like quite the fireworks display. Use a
fqaceshield, heat-resistant clothing, and all other precautions
when dealing with molten, buring, hot stuff.
Also keep in mind, if you're going to be casting high carbon
steel, that if it cools too fast, it may shatter under the
stresses. OTOH, if you cool steel down too slow you'll get a
lot of grain growth, which can only be removed by forging or
really painstaiking heat treatment.
Casting steel seems to be a lot more challenging than bronze or
silver; I’ve decided to put the idea on hold for a while until I have
more experience. (Unreleated but cool aside: casting a pewter stool
at the beach:
Regarding finding someone to cast your design, I don’t know. I would
check your local dental labs and blacksmiths. There may be forums or
websites where you could put the job up for a bid; I would ask for
leads to such job boards heRe: http://www.anvilfire.com/slacktub/ and
maybe ask the moderator of the internetdentalforum.net Tim Lane,
although I’m not sure if that’s a particularly good way of looking
You’ll probably have more success asking the swordsmith Rick Barrett,
who did the legwork for this when he found someone to cast the steel
pommel for his sword LongClaw:
I’ll forward your email to him.