Tools and hardfacing

["Bob Hackett" <kinfolk@zzzzzzz>]

    Ok,here we go.
  Most of the quality tools you see today are made of  some form of high
carbon steel(HCS) as opposed to mild steel such as hot rolled(looks like
it's been thru a fire) and cold rolled(the brighter looking steel down at
Home Depot).
  The addition of carbon allows the steel to be hardened and tempered.The
degree of hardness needs to match the intended use of the tool.Most
toolsteel(HCS) that we come in contact with and can use will either be oil
or water hardening.It's a pretty safe bet to use things like old jackhammer
bits,old picks and mattocks,chisels,large files,pry bars etc.If a file
skates off the steel chances are it'll be HCS.
   The first thing you want to do with your newly found prize is anneal
it.This will make the steel soft enough to work with things like
files,hacksaws,etc.The way to anneal HCS is to heat it to cherry red(between
1300/1400+ deg) and let it cool slowly by either burying it in ash or
lime.Throwing it in the woodstove and leaving it overnight will usually work
too(and allows you time to practice your dance steps).It's a good idea to
start off with annealed steel even if you're going to work the steel by
forging.Some old timers refer to annealed(soft) HCS as being "Dead soft" and
this is what explains the lack of rebound when struck.It's not a good idea
to strike 2 pieces of  hardened steel together(like 2 hammer heads or an axe
head and a hammer)as they can fracture or spall and the pieces are, for all
intents and purposes,shrapnel,with the same results.
  The chisels that we use have soft shanks that allow them to deform(or
mushroom) instead of fracturing. The woodsplitting malls that were talked
about for splitting  stone have a soft striking surface so they can be hit
with a sledge to free them if need be(think of them as large chisels with
handles).
  Whenever you want to make a tool that will be struck by a hammer and have
a tough cutting edge you need to either temper the tool differently at
either end(hard at the cutting end,soft at the striking end.Firesharp
chisels for marble and limestone are a good example of this) or clad the
cutting end with hardface.
  Hardface rod is just a way to clad the face of the steel with carbide to
keep it from wearing as quickly.It's much the same substance as the tungsten
carbide tipped chisels you get to work granite.Those chisels you bought
probably had a solid carbide tip brazed on but cladding is almost as
good.Hardface rod is sold either as a coated rod for use in an arc
welder(SMAW process) or as an uncoated wire for use in MIG or TIG welding.A
good place to find someone who knows about this stuff is wherever they
repair heavy equipment as bucket loaders and excavators usually have the
bucket teeth hardfaced after welding(You always wondered why there was so
much welding on the outside of those buckets,now you know).These machines
wrestle with stone day after day and need every edge they can get(pun
intended).
  The better welders will preheat and post heat to be sure the hardface
doesn't crack or break away from the parent metal.That's why it's always
good to go to the experts as opposed to the pros(a pro is ANYONE who does
something for money.I've seen really bad pros and very talented
amateurs).The other thing to keep in mind is that hardface is a BEAR to
grind so you want to lay it on as smooth as you can and maybe hot work it
with a hammer at the edge.You will go thru an amazing amount of grinding
wheels and make a very large mess trying to grind this stuff.Use a "green
wheel" on a bench grinder to resharpen or use diamond.
  If you're going to clad a tool,think about the fact that the steel behind
the clad will still be relatively soft and build accordingly in cross
section.
    If  you'd like to know more about unclad HCS tools(firesharps) let me
know and I'll post again later.I told you this was long and boring.
  BTW-what I'm telling you is just the way I and those I know do
things.There are more than 1000 ways to skin any cat,this is just the one
that works for me,YMMV.If there are any other metalheads out there please
feel free to chime in or disagree.I'm sure I missed about 100 important
things in this long post but it'll get you started in the right directions.

   Books to read;  Toolmaking for Woodworkers by Ray Larsen,everything you
need to know to get you started.From building a coal fire to scouting out
and working steel,heat treating too,Ray covers it all.
    Any books by Alexander G. Weygers,his three volume set is out of
print.The compliation may still be out there though.
  The Anvil's Ring,a newsletter put out by ABANA.Look for toolmaking
articles as opposed to ornamental ironwork.

  Last but not least,nothing beats going to the nearest forge and seeing a
smith at work.Knifemakers are an excellent source of toolmaking knowledge
too.
  Go out and try to make friends with those crusty old dudes with the
leather aprons.Show them your druid dance,they'll be impressed. It'll either
help to break the ice or freeze 'em right up solid.Check the slack tub if
you're unsure as to the results.

Mainely,Bob