I would like to reshape a raising hammer that I bought. Its has two
cross peen ends and right now they are both of fairly similar size.
I would like to reshape one end to be thinner, more chisel-like than
the other.
I have read and was told that I needed a grinding wheel for this. I
don’t have access to such an equipment but I do own a foredom flex
shaft and files. Is it possible to do what I want with just with the
tools that I have? I don’t mind taking the time, if it takes a
little longer, and would appreciate any tips from anyone who has
successfully done this with their flexshaft and/or files.
I have read and was told that I needed a grinding wheel for this
I have reshaped hammers just fine with files, sandpaper and a
buffing wheel for the final shine. It is time-consuming, but
pleasurable. I would be concerned that a grinding wheel would create
too much heat, and cause trouble, and the deep scratches would be a
lot of work to remove anyway.
“Raising Hammer” sounds reasonably large. Probably too large for
your flexshaft. Riveting hammers, tack hammers, these you might
conceivably get away with using the flexshaft.
You certainly can file it down - long process but doable. I would
maybe use a dedicated file for the steel and no what you use on your
jewelry metals. Grinding wheels are are almost as much work as they
leave such a faceted surface. Best of all is an expandable drum using
wet/dry sandpaper. Goes really fast and blends your passes because of
the give in the rubber the unit is made of. Lapidary supply houses
offer these. You would have to spend some bucks and time putting this
rig together so it may out of the question.
Purchase some 240, 320, 400, 600 and 1500 grit wet/dry sandpaper and
get a couple of paint sticks to wrap it around. Use the sandpaper
(wet) from 240 through the 400 to smooth out the file marks and put a
satin finish on the hammer. I personally do my major raising with the
400 finish (make your sanding direction parallel to the long axis of
the pein). It gives the hammer some “tooth” and the process goes much
faster. The fine texture inparted to the metal disappears quickly
during planishing.
If you’re goint to use the raising hammer mark as a finished surface
then when you’ve got two or three rounds left to go finish sanding
out the hammer to the 1500 grit. From here you would have to use
stainless steel compound to put a polish on it but you’ll need a
regular buffing unit as, again, your flexshaft just won’t cut it.
You can do it with files but if you have much metal to remove, it
will take a long time. An angle grinder which is hand held would be
my preference. I would follow that with createx wheels on a buffing
machine and finish with bobbing compound. I would not use a
flexshaft at all.
I use a belt grinder starting with 36 grit and working up to 600
grit, keeping the hammer cool during the stock removal. Then I polish
and buff with different compounds. The angle grinder maybe too
aggressive and cause too much heat during the process.
I make my own hammers, generally from other hammers, but now and then
I start from scratch.
Some hammer I heat treat and temper, sometimes for very hard hammer
faces, I just heat treat.
Before you start filing away, you should be aware that quality
hammers are finished with the process called “packing”. Metal brought
to relatively low temperature and in that state is compressed with
strategically placed blows. I do not know which hammer you have, but
if it was packed, you will file this layer away which would give you
hammer useable only for rough work. Run of the mill hammers are not
treated that way, but they are not expensive and why not simply buy
another one in this case.
If you like filling that much, get a raw steel, file it to the shape
you want and temper. It would take you less time that grinding away
the hammer which was tempered already.
I would like to reshape a raising hammer that I bought
Metalsmiths do this all the time. It is called “dressing” your
hammer. Most new hammers have to be reshaped before use, unless they
have been “dressed” by the seller (Allcraft will do this for a small
charge). Sometimes the metalsmith just wants a hammer with a
different shape.
To reshape your hammer, use your files or a belt sander, (if you
have access to one). Start with the coarsest grit or file that you
own. Once you get close to the shape you want, start using smoother
files or less abrasive sandpaper. Work towards 400-600 grit - each
time eliminating the marks from the previous grit. If you want a
high polish, buy some, “stainless steel” polish from Allcraft. It
comes in a white bar and produces a great polish on steel. Use it on
a buff that you will not use for anything else other than this
polish.
Make sure you don’t leave any sharp edges on your hammer that could
dig into your work. Everything that could touch your work should
have curves that blend smoothly into each other.
I don’t think a flexshaft has the power to dress a hammer, unless it
is a really small one or you have lots of time.
... Is it possible to do what I want with just with the tools that
I have?
In a word, yes. I’ve done this many times – almost every new hammer
it seems, sooner or later – so yes, it is quite possible.
As to whether it’s ideal or not is quite another question. As you’ve
surmised it can be very slow going. It can also be quite hard on
your equipment, especially if you’re impatient and try to speed
things up by applying more pressure etc. And it’s incredibly messy
because you have the whole thing in your hands, as opposed to a bench
grinder where a lot of the dust and grindings are directed downwards,
or into a dust trap.
If you do decide to go this route I would recommend the following:
a full face shield, not just goggles.
a serious dust mask, NOT one of the paper disposable ones.
a full smock that closes around the wrists and neck.
ear protection.
a good selection of grinding wheels, available at auto body or
marine shops.
water for coolant (you’ll need to cool your workpiece frequently).
patience.
Note that the grinding wheels mentioned above are usually rated at
5000 RPM maximum. That’s at the very bottom end of the speed chart
for your garden variety flex shaft so either (a) use a flex shaft
that can run comfortably at those low speeds or (b) change to
abrasives that are rated at 10,000 RPM or higher.
If you have to use a regular flex shaft (not a low speed version)
then look for “cut off” wheels which are quite aggressive cutters AND
can be stacked to form a larger cutting surface. They usually come in
three grades of coarseness, go for the coarsest you can find. Buy a
tube or two of them because you’ve going to be burning through them
fairly quickly.
Go lightly and don’t apply too much pressure, take your time, let
the tool do the work. If you are bogging the machine down then you’re
working it too hard: back off or you’ll be repairing your flex shaft
before you’re done.
I make my own hammers, generally from other hammers, but now and
then I start from scratch.
Well, good, cuz I could use some pointers, maybe… I have a hammer
head and would like to put it on a handle. Never done it, and would
like to learn from someone else’s experience-- dos and don’ts?
Before you start filing away, you should be aware that quality
hammers are finished with the process called "packing". Metal
brought to relatively low temperature and in that state is
compressed with strategically placed blows.
Packing is an old blacksmiths myth, it doesn’t occur. The idea was
that you could somehow “pack” or compress the metal by hammering it
at low temperature to make a harder face or cutting edge. You cannot
compress the crystal matrix by hammering. The atomic latice spacing
is not compressible in this fashion. The only efect a packing
procedure may have is some work hardening of improperly or
insufficiently heat treated steel.
If the tool was case hardened than you could definitely grind
through the case and expose the soft metal underneath. However case
hardening is useless for hammers as you will crack the case fairly
rapidly with the impact of hammering.
If you like filling that much, get a raw steel, file it to the
shape you want and temper. It would take you less time that
grinding away the hammer which was tempered already.
Tempering is the softening stage of steel heat treating. You must
harden it first then temper it to make it less brittle. Tool steel
has two mutually exclusive properties hardness and toughness. The
harder you make it the more brittle it becomes and the more likely
to shatter when struck. The tougher it is the more you will be able
to deform it from impact or other forms of pressure. When steel is
heat treated it is taken above the “critical temperature” (varies
depending on which variety of tool steel) then quenched (in water,
brine, oil or air again depending on the tool steel) at which point
it is very hard. Some tool steels can actually fracture like glass
if they are dropped or otherwise shocked at this point. Then these
tools are “tempered” or “drawn” to make them tougher and less hard.
The tempering process involves heating to 300-1200F depending on the
type of steel and the desired hardness the lower temperatures provide
a harder steel that makes for better cutting edges but is still
brittle and can easily chip. This is suitable for gravers or knives.
The mid range temperatures are useful for tools that must be both
sharp and withstand impact like die sinkers chisels or axes. The
highest tempering temperatures are for tools like hammers that have
high impact uses like hammers.
Making your own tools is a lot of fun and you can make just the
right hammer, punch, graver or whatever. I make lots of my tools an
would encourage those that have the inclination to do so to try it.
But it is also a good idea to make acquaintance with a blacksmith who
can help you with the making of the occasional larger tool and then
you don’t need to have another set of tools (blacksmiths) to clutter
up the shop.
James Binnion @James_Binnion
James Binnion Metal Arts
Tempering is the softening stage of steel heat treating. You must
harden it first then temper it to make it less brittle.
There is a difference in using tempering as a metallurgist or as it
applies to making a tools in the jewellery shop. Since fancy
equipment is not available, they way I was taught is to bring the
hammer, or any other tool, to bright red and quench it in brine, but
not completely, only working surface gets submerged by no more than
a millimeter, and tool is kept in this position until no more red can
be seen. Then the whole tool is quenched. Done this way a very hard
layer is achieved on the surface with progressive softening towards
the center. Similar to the case hardening but better. No other heat
treatment is required. That is why it is called tempering, and that
is why filing a hammer is not a good idea, unless hammer is cheaply
made.
As far as packing been a myth:
You said it yourself that by striking metal repeatedly a work
hardening will be the result. It should be obvious that by increasing
temperature the effect is magnified as long as temperature is held
under the threshold when re-crystallization begins. If you do not
like the word “packing” I can leave with “work hardening”. The effect
is still the same.
Heating treating a hammer is not a complex process, but it can be.
Have your handle removed so you have the hammer head. The face that
you reground, heat it with a propane torch. If you can get it to glow
thats really great, but get it as hot as you can otherwise. Then
while hot, drop it in to a metal bucket of water. Once it is cooled
down, it has basic heat treating. To temper the hammer head, place it
in your kitchen oven at 400 degrees F or about 200 Degree C for about
3 hours, let cool to about 125 degrees F or 52 degrees C, then set
you
kitchen oven at 200 degree F or about 90 degrees C for about 2 hours,
then it will be tempered as well as HT’d. Put the handle back on
after the hammer head has cooled to room temperature. Polish hammer
face with very fine grit sand paper, and the use a polish like Zam on
a buffer or a wheel, your done.
We can have lots of discussion of precision HT and Tempering, but
this method is for those you don’t have the equipment or the
technical expertise. It does work, not has well as some one how has
HT equipment.
There is a difference in using tempering as a metallurgist or as it
applies to making a tools in the jewellery shop. Since fancy
equipment is not available, they way I was taught is....
Calling an orange an apple doesn’t make it an apple. What you are
doing is first hardening the hammer by heating then controlled
quenching of the face. Then you are using the residual heat to
temper it. Two processes,two names. And very difficult to control in
small tools it requires a lot of skill to judge the appropriate time
to complete the quench. Also many tool steels will not respond to
this type of heat treating in a favorable manner. Using the name for
one process to describe another just leads to confusion. Heat
treating is preformed in crude to highly sophisticated settings it
doesn’t matter if you are a third world blacksmith or a process
control engineer the physics is the same. It doesn’t matter if you
are in the jewelry shop or industrial factory, the established names
for the processes allow us to talk about them with everyone able to
understand what is being said.
You said it yourself that by striking metal repeatedly a work
hardening will be the result. It should be obvious that by
increasing temperature the effect is magnified as long as
temperature is held under the threshold when re-crystallization
begins. If you do not like the word "packing" I can leave with
"work hardening". The effect is still the same.
If it is done after heat treating (hardening and tempering) the only
way you will get any significant work hardening is if the heat
treating was not done properly and the metal has been left soft.
Packing was done at a heat below the forging heat and before heat
treating. Any possible changes to the tools properties from packing
would go away when the tool is heated to critical temperature.
Packing is not work hardening.
James Binnion @James_Binnion
James Binnion Metal Arts
You make a good point about importance of precision in describing
technical processes. However, original post was about reshaping
hammers. The term “tempered” was used as an indication of different
state that finished hammers are in, as opposed to raw steel.
Even if we accept, for argument sake, that the heat treatment
process always as you described it, the tempering is still the last
phase of the process, and therefore I do not find the term "tempered"
as objectionable as you do.
I will concede that term “heat treated” would have been more
appropriate, but given the nature of the original post I do not
believe that “tempered” confused anybody.
About packing.
If heating steel returns molecules to the original state without any
residual effects, how do you explain the difference in durability
between forged items and items that were machined. According to
theory as you describe it, there should not be any difference, but
the difference does exist. You overlooking that effect of hardening
as a result of the heat treatment, have more to do with the presence
of carbon, then with the molecular structure of the steel. Of course,
I can only speak of alloys containing carbon. I have no knowledge how
alloys with such additives like Vanadium, Molibdenium, and the like
would behave.
Heating treating a hammer is not a complex process, but it can
be. Have your handle removed so you have the hammer head. The face
that you reground, heat it with a propane torch. If you can get it
to glow thats really great, but get it as hot as you can otherwise.
Then while hot, drop it in to a metal bucket of water. Once it is
cooled down, it has basic heat treating.
If it is not heated above 1400F (which is definitely glowing) before
quenching it will not harden. You will just anneal it
James Binnion @James_Binnion
James Binnion Metal Arts
If heating steel returns molecules to the original state without
any residual effects, how do you explain the difference in
durability between forged items and items that were machined.
According to theory as you describe it, there should not be any
difference, but the difference does exist.
On the micro scale after heat treatment there is very little
difference between forged and machined from bar stock items as far
as crystal size and structure. The reason for this is that they are
both plasticly formed structures. The bar stock that is used to make
the machined item is plasticly deformed by a rolling mill to achieve
its basic shape. And the forged item is plasticly formed under the
hammer. On the macro level there will be residual directionality of
the grain that would indicate the method of manufacture but in most
cases this is not a performance issue. In certain highly stressed
parts (aircraft landing gear for example) the forged item may be the
superior one, but not in typical use.
There is however a significant difference if the item was machined
from as cast stock or a near net shape casting. Both machined from
bar and forged will have a fine grain structure that is relatively
uniform, cast material however will retain much of the grain
structure it developed when solidifying which is much coarser and
more varied in size and much more likely to fracture with heavy use.
But the original discussion was about packing, it does not impart
significant grain structure changes in the material before heat
treating and presents none afterwards.
You overlooking that effect of hardening as a result of the heat
treatment, have more to do with the presence of carbon, then with
the molecular structure of the steel.
So you are saying you would be just as happy with a cast hammer as a
forged one? If they both have the same carbon content and they are
heat treated the same way? I doubt it. The only difference is the
microstructure of the steel.
James Binnion @James_Binnion
James Binnion Metal Arts
So you are saying you would be just as happy with a cast hammer as
a forged one? If they both have the same carbon content and they
are heat treated the same way? I doubt it. The only difference is
the microstructure of the steel.
Not at all, I am simply trying to say that if we recognize difference
between forged and machined items, it is not a stretch to say that
“packing” which is nothing else than simply light forging at lower
temperature, has beneficial effects as well.