Greetings,
I'm looking at making my own plane blades (and other tools, too). I
found OnlineMetals.com has O-1 in the appropriate sizes. I've got some
chip-carving blades (nee hacksaw) tempering in the oven right now.

It occurred to me as I removed oxidation from the blades after
hardening that for a 2" by, say, 3/16" blade, I should really be
ordering 2.5" x 1/4" (or 7/32") stock. True?

Thanks for your advice
--
"Keep your ass behind you."


Why would you want to do that?

Two main reasons for starting with oversize stock.

To allow grinding to final size after hardening, to take care of any warping
from the hardening process. In your case, the final size is not critical, and
a slightly warped blade will be flattened out when it is clamped down.

To get past any scale or surface decarburization. If you have a heat treating
oven, you probably already know about the use of stainless foil or anti-scale
coatings.

Do you have a surface grinder? If you do, go ahead with the oversize stock.

John Martin

"Australopithecus scobis" wrote in message
...
Greetings,
I'm looking at making my own plane blades (and other tools, too). I
found OnlineMetals.com has O-1 in the appropriate sizes. I've got some
chip-carving blades (nee hacksaw) tempering in the oven right now.

It occurred to me as I removed oxidation from the blades after
hardening that for a 2" by, say, 3/16" blade, I should really be
ordering 2.5" x 1/4" (or 7/32") stock. True?

1/4" is 'way too thick for a plane iron (for a hand plane, that is), and you
shouldn't be losing much, if any, stock to oxidation anyway.

What you want to do is to protect your steel from oxidation. You shouldn't
be heating tool steel to its transition temperature in plain air. Tempering
should not cause noticable oxidation, although it will change the surface
color due to a very thin oxide layer. That doesn't require a thicker blade;
if you object to the color, you can polish it off or, in most cases, you can
etch it off with a quick wipe of Naval Jelly or other source of phospohoric
acid.

You should do something either to protect the surface of the steel or to
raise the carbon potential in your furnace when you're heating it to harden
it. This may be as simple as coating your steel with ordinary bar-type
laundry soap before sticking it in the furnace.

What kind of furnace are you using?

Ed Huntress

"Australopithecus scobis" wrote in message
...
In article ,
"Ed Huntress" wrote:

What kind of furnace are you using?

I'm learning with the wee blades. I do those with a propane torch. I
haven't rigged a forge for bigger stuff. I do wood; I'm picking up
metalwork skills as I need them.

When I do put the forge together, it'll probably be a kneeler: stacked
refractory bricks, charcoal, and a hairdrier. (Lurking here I learned
about two kinds of refractory brick.)

Answering another kind post he No, I didn't know about stainless
foil or anti-scale coatings. Now I do. Thanks.

Back on topic, the gist is that I don't have to get oversized stock.
Thanks.

Yes, that's the bottom line. It's a lot easier to prevent damaging oxidation
than it is to remove it from your finished piece.

BTW, if you stick to very small pieces in the beginning, to get you started,
you can make an ersatz furnace out of 10 or 12 firebricks and a couple of
propane torches aimed to distribute the heat more effectively than you can
with one torch. That's how I heat things like homemade chisels and plane
irons, and I've gotten away with it for over 30 years.

However, make something better as soon as you can, if you plan to do more
than very infrequent heat treating. For small woodworking tools, I'd go with
an electric furnace that I could use safely and easily in my shop. It's slow
to heat, but avoid using firebrick; stick to something with a lot less
thermal mass, and it will go quicker. There are some ceramic-fiber blanket
materials. They're expensive, but, for plane irons and such, your furnace
can be very small and you won't need much of it.

Ed Huntress

Ed Huntress wrote...

1/4" is 'way too thick for a plane iron (for a hand plane, that is), and you
shouldn't be losing much, if any, stock to oxidation anyway.

Right on the second point, but 1/4" is an excellent thickness for a plane
iron, especially if you're making a wooden-body plane. Unless you are
making a replacement iron for a Norris- or Bailey-style plane and have
clearance issues, thicker up to about 1/4" is almost always better, for a
variety of reasons.

What you want to do is to protect your steel from oxidation. You shouldn't
be heating tool steel to its transition temperature in plain air.

For sure. Assuming (!) the OP doesn't have access to a heat-treat oven
and is using some type of propane setup, an easy way to limit oxidation
is to choke off the forge openings to create a slightly reducing
atmosphere. This is easily achieved even in a simple coffee-can forge
fired by a propane torch.

Tempering should not cause noticable oxidation, although it will change
the surface color due to a very thin oxide layer. That doesn't require a
thicker blade; if you object to the color, you can polish it off or, in
most cases, you can etch it off with a quick wipe of Naval Jelly or other
source of phospohoric acid.

The flattening and honing will polish some of the face (back) and
probably all of the bezel. Like Ed said, the oxidation color doesn't hurt
anything, but it does buff off quickly with a Maroon Scotch-Brite pad
(7447), if you want.

You should do something either to protect the surface of the steel or to
raise the carbon potential in your furnace when you're heating it to harden
it. This may be as simple as coating your steel with ordinary bar-type
laundry soap before sticking it in the furnace.

That's another good idea, and it seems to help release the crust from
quenching in oil, too.

Jim

"Jim Wilson" wrote in message
ink.net...
Ed Huntress wrote...

1/4" is 'way too thick for a plane iron (for a hand plane, that is), and
you
shouldn't be losing much, if any, stock to oxidation anyway.

Right on the second point, but 1/4" is an excellent thickness for a plane
iron, especially if you're making a wooden-body plane. Unless you are
making a replacement iron for a Norris- or Bailey-style plane and have
clearance issues, thicker up to about 1/4" is almost always better, for a
variety of reasons.

If he's making his own planes, he can make them as thick as he wants to, and
I agree, thicker is better. My old wooden-bodied Stanleys actually use
thinner blades than modern ones, but I've relieved the mouths so they can
take greater thicknesses, because the thin ones chatter.

But I think what he was referring to was making them thick and then grinding
off the bark and scale. Even if you do that, you'll have to do one hell of a
lot of grinding to get that iron to fit in any normal commercial plane.


What you want to do is to protect your steel from oxidation. You
shouldn't
be heating tool steel to its transition temperature in plain air.

For sure. Assuming (!) the OP doesn't have access to a heat-treat oven
and is using some type of propane setup, an easy way to limit oxidation
is to choke off the forge openings to create a slightly reducing
atmosphere. This is easily achieved even in a simple coffee-can forge
fired by a propane torch.

What does a coffee-can forge look like? It sounds like something that's
right in my price range. g

Ed Huntress


Tempering should not cause noticable oxidation, although it will change
the surface color due to a very thin oxide layer. That doesn't require a
thicker blade; if you object to the color, you can polish it off or, in
most cases, you can etch it off with a quick wipe of Naval Jelly or
other
source of phospohoric acid.

The flattening and honing will polish some of the face (back) and
probably all of the bezel. Like Ed said, the oxidation color doesn't hurt
anything, but it does buff off quickly with a Maroon Scotch-Brite pad
(7447), if you want.

You should do something either to protect the surface of the steel or to
raise the carbon potential in your furnace when you're heating it to
harden
it. This may be as simple as coating your steel with ordinary bar-type
laundry soap before sticking it in the furnace.

That's another good idea, and it seems to help release the crust from
quenching in oil, too.

Jim

Unless you are removing the oxidation in order to see the colors run
during tempering why bother?
Lap the back of the iron flat and put an edge on it.

Well, refresh after send and two more messages render much of my first
post moot! (G)

Ed Huntress wrote...

However, make something better as soon as you can, if you plan to do more
than very infrequent heat treating. For small woodworking tools, I'd go with
an electric furnace that I could use safely and easily in my shop. It's slow
to heat, but avoid using firebrick; stick to something with a lot less
thermal mass, and it will go quicker.

If your budget or inclination leads you to want to *make* an electric
furnace, rather than buy one, some good ideas can be found in the
glassworking hobby community. Those guys are even cheaper than HSMs. (G)

There are some ceramic-fiber blanket materials. They're expensive, but, for
plane irons and such, your furnace can be very small and you won't need much
of it.

Unfortunately, it can be hard to find small quantities of this stuff
without paying outrageous prices. Here are a couple sources

Jay Hayes: http://home.earthlink.net/~xmas4lites/
(but I don't know if Jay is still selling the Kaowool.)

anvilfire sto http://www.anvilfire.com/sales/pages/index.htm
(This site requires a Java plug in. You can get the 6-lb. material for
about $3.50 per sqare foot, in 2-sq ft increments.)

If you decide to go this route, the ITC thermal coatings are a good idea,
to increase IR reflectivity and durability of the blanket material, and
to prevent airborne dust from it. They are expensive, though, typically
$30-$40 / pint, depending on where you buy it.

Jim

A good source of electric kilns is the ceramic community. You can pick
up older kilns which are a bit tired and in need of new elements fairly
cheap. When I say need new elements, the elements have aged and won't
reach a high enough temperature for a lot of ceramics but they are fine
for heating metal for hardening, tempering and normalising. I have a
18" kiln which I use for this and glass work. When new it would fire to
1300C but now struggles to 1100C.

Ed Huntress wrote:

"Australopithecus scobis" wrote in message
...

In article ,
"Ed Huntress" wrote:

What kind of furnace are you using?

I'm learning with the wee blades. I do those with a propane torch. I
haven't rigged a forge for bigger stuff. I do wood; I'm picking up
metalwork skills as I need them.

When I do put the forge together, it'll probably be a kneeler: stacked
refractory bricks, charcoal, and a hairdrier. (Lurking here I learned
about two kinds of refractory brick.)

Answering another kind post he No, I didn't know about stainless
foil or anti-scale coatings. Now I do. Thanks.

Back on topic, the gist is that I don't have to get oversized stock.
Thanks.


Yes, that's the bottom line. It's a lot easier to prevent damaging oxidation
than it is to remove it from your finished piece.

BTW, if you stick to very small pieces in the beginning, to get you started,
you can make an ersatz furnace out of 10 or 12 firebricks and a couple of
propane torches aimed to distribute the heat more effectively than you can
with one torch. That's how I heat things like homemade chisels and plane
irons, and I've gotten away with it for over 30 years.

However, make something better as soon as you can, if you plan to do more
than very infrequent heat treating. For small woodworking tools, I'd go with
an electric furnace that I could use safely and easily in my shop. It's slow
to heat, but avoid using firebrick; stick to something with a lot less
thermal mass, and it will go quicker. There are some ceramic-fiber blanket
materials. They're expensive, but, for plane irons and such, your furnace
can be very small and you won't need much of it.

Ed Huntress

Ed Huntress wrote:

"Jim Wilson" wrote in message
link.net...


Ed Huntress wrote...



1/4" is 'way too thick for a plane iron (for a hand plane, that is), and


you


shouldn't be losing much, if any, stock to oxidation anyway.


Right on the second point, but 1/4" is an excellent thickness for a plane
iron, especially if you're making a wooden-body plane. Unless you are
making a replacement iron for a Norris- or Bailey-style plane and have
clearance issues, thicker up to about 1/4" is almost always better, for a
variety of reasons.



If he's making his own planes, he can make them as thick as he wants to, and
I agree, thicker is better. My old wooden-bodied Stanleys actually use
thinner blades than modern ones, but I've relieved the mouths so they can
take greater thicknesses, because the thin ones chatter.

But I think what he was referring to was making them thick and then grinding
off the bark and scale. Even if you do that, you'll have to do one hell of a
lot of grinding to get that iron to fit in any normal commercial plane.


Came in at the middle of this but Japanese planes tend to have very
thick blades. Thick is REALLY good. I can pull see-through shavings
with a japanese plane due to lack of chatter. It leaves a glass smooth
finish on even curly woods and is also easy to sharpen. I'd never go
back to those thin Stanley pieces of crap.

Koz




What you want to do is to protect your steel from oxidation. You


shouldn't


be heating tool steel to its transition temperature in plain air.


For sure. Assuming (!) the OP doesn't have access to a heat-treat oven
and is using some type of propane setup, an easy way to limit oxidation
is to choke off the forge openings to create a slightly reducing
atmosphere. This is easily achieved even in a simple coffee-can forge
fired by a propane torch.



What does a coffee-can forge look like? It sounds like something that's
right in my price range. g

Ed Huntress



Tempering should not cause noticable oxidation, although it will change
the surface color due to a very thin oxide layer. That doesn't require a
thicker blade; if you object to the color, you can polish it off or, in
most cases, you can etch it off with a quick wipe of Naval Jelly or


other


source of phospohoric acid.


The flattening and honing will polish some of the face (back) and
probably all of the bezel. Like Ed said, the oxidation color doesn't hurt
anything, but it does buff off quickly with a Maroon Scotch-Brite pad
(7447), if you want.



You should do something either to protect the surface of the steel or to
raise the carbon potential in your furnace when you're heating it to


harden


it. This may be as simple as coating your steel with ordinary bar-type
laundry soap before sticking it in the furnace.


That's another good idea, and it seems to help release the crust from
quenching in oil, too.

Jim

On Fri, 26 Mar 2004 15:32:43 GMT, "Ed Huntress"
brought forth from the murky depths:

"Australopithecus scobis" wrote in message
...
Greetings,
I'm looking at making my own plane blades (and other tools, too). I
found OnlineMetals.com has O-1 in the appropriate sizes. I've got some
chip-carving blades (nee hacksaw) tempering in the oven right now.

It occurred to me as I removed oxidation from the blades after
hardening that for a 2" by, say, 3/16" blade, I should really be
ordering 2.5" x 1/4" (or 7/32") stock. True?

1/4" is 'way too thick for a plane iron (for a hand plane, that is), and you
shouldn't be losing much, if any, stock to oxidation anyway.

Ron and Steve beg to differ, and I agree. I have irons from
Hock (3/16" thick) and planes from Knight (1/4" thick iron)
and love them to death. AAMOF, I'm using the Knight smoother
to refinish the redwood (under all that RBS someone smeared
onto it years ago) mantle today.

http://www.hocktools.com/ and www.knight-toolworks.com


--------------------------------------------------------
Murphy was an Optimist
----------------------------
http://diversify.com Comprehensive Website Development

Ed Huntress wrote...

What does a coffee-can forge look like? It sounds like something that's
right in my price range. g

I'm sure it would be. (G) It looks pretty much like what you'd toss in
the trash bin after the contents are consumed, but the ends have been
removed.

I thought sure I'd find a picture of one on the net for you, but Google
doesn't seem to stock any. (G) Maybe I'll add a little web page with some
pics and tips. They are so common, I can't believe someone hasn't already
put up a page on one. They're cheap, very easy to make, and surprisingly
handy. Mine gets nearly as much use as my mini propane-tank forge, which
runs a Reil propane burner.

The coffee can forge is cradled in a pair of legs bent from 1/8 x 3/4" or
1" mild steel strip. It's lined with 1" 6# ceramic wool blanket. A 1"
thin slice of soft firebrick provides the floor; it's slightly more
durable than the wool. A ceramic shelf would be better, but I didn't have
any. There's a 5/8" or so hole in the side about midway between the open
ends, around the 10 o'clock position. A swirly propane torch nozzle fits
through the hole. That's pretty much it.

A piece of the wool covers top half of the back opening. The front
opening is usually closed off a bit by the hearth, which is just a fire
brick sitting on its side in front of the opening. The atmosphere in the
is controlled by choking the front and back openings more or less with
scrap firebrick. I generally close off the back a little more than the
front, except when I want to limit the portion of the workpiece that's
brought to temperature.

And then there's the picoforge (TM), made by hollowing out a single
firebrick. (I just made that name up.) It is also powered by a propane
torch. I don't have one of these, but I've seen a couple over the years.

Jim

I'm a woodworker doing the same thing. I've made many tools including a
full set of bevel edge chisels, flush trimming chisels, corner chisels,
mortise chisels, lathe scrapers... out of O1 tool steel. I get very little
carbonization on the tools from hardening and even less from tempering. If
I were going to make a plane blade I'd use precision ground 1/8 thick O1 too
steel 3/16 and especially 1/4 are far too thick. After you've hardened and
tempered back the tool steel you will find out real fast that trying to
grind the blade back to a reasonable thickness is going to be a very long
process. Another thing you might want to consider, what I've learn from the
many chisels and other tools I've made is unless the tool will be use to
"leverage" like a mortise chisel you may want to consider not tempering
back. You'll have a blade that will hold an increadible edge and be also
harder than any chisel or plane blade you have now. The blades I've made
that I have not tempered back don't show any sign of a chipping problem. To
avoid warping make sure the oil you use for quenching is quite hot to the
touch. Another thing to help reduce warping, cause its a plane blade there
is no need to harden any more than the first 1 1/2


"Australopithecus scobis" wrote in message
...
Greetings,
I'm looking at making my own plane blades (and other tools, too). I
found OnlineMetals.com has O-1 in the appropriate sizes. I've got some
chip-carving blades (nee hacksaw) tempering in the oven right now.

It occurred to me as I removed oxidation from the blades after
hardening that for a 2" by, say, 3/16" blade, I should really be
ordering 2.5" x 1/4" (or 7/32") stock. True?

Thanks for your advice
--
"Keep your ass behind you."

"Jim Wilson" wrote in message
ink.net...
Ed Huntress wrote...

What does a coffee-can forge look like? It sounds like something that's
right in my price range. g

I'm sure it would be. (G) It looks pretty much like what you'd toss in
the trash bin after the contents are consumed, but the ends have been
removed.

I thought sure I'd find a picture of one on the net for you, but Google
doesn't seem to stock any. (G) Maybe I'll add a little web page with some
pics and tips. They are so common, I can't believe someone hasn't already
put up a page on one. They're cheap, very easy to make, and surprisingly
handy. Mine gets nearly as much use as my mini propane-tank forge, which
runs a Reil propane burner.

The coffee can forge is cradled in a pair of legs bent from 1/8 x 3/4" or
1" mild steel strip. It's lined with 1" 6# ceramic wool blanket. A 1"
thin slice of soft firebrick provides the floor; it's slightly more
durable than the wool. A ceramic shelf would be better, but I didn't have
any. There's a 5/8" or so hole in the side about midway between the open
ends, around the 10 o'clock position. A swirly propane torch nozzle fits
through the hole. That's pretty much it.

A piece of the wool covers top half of the back opening. The front
opening is usually closed off a bit by the hearth, which is just a fire
brick sitting on its side in front of the opening. The atmosphere in the
is controlled by choking the front and back openings more or less with
scrap firebrick. I generally close off the back a little more than the
front, except when I want to limit the portion of the workpiece that's
brought to temperature.

And then there's the picoforge (TM), made by hollowing out a single
firebrick. (I just made that name up.) It is also powered by a propane
torch. I don't have one of these, but I've seen a couple over the years.

They sound very clever, Jim. If you put up some photos, I'd like to see
them.

You may want to point out one caution here to hobbyists who try the
atmosphere trick. I'm not sure about propane, but this is true for natural
gas: burning it with insufficient air, as in your routine for making a
reducing atmosphere, generates a lot of carbon monoxide in a hurry. In fact,
carbon monoxide is a furnace gas used in industry for just this purpose. But
they burn off the vented gas to keep from killing themselves.

Unless someone is sure that propane doesn't generate CO under these
conditions (which would surprise the heck out of me, but I'm no chemist), it
doesn't sound like something you'd want to do indoors.

Thanks for the info.

Ed Huntress

Ed Huntress wrote...

If you put up some photos, I'd like to see them.

Sure thing. I'll be out of town tomorrow, but I'll try to take a couple
photos Sunday.

You may want to point out one caution here to hobbyists who try the
atmosphere trick. I'm not sure about propane, but this is true for natural
gas: burning it with insufficient air, as in your routine for making a
reducing atmosphere, generates a lot of carbon monoxide in a hurry.

That is absolutely true for propane as well, and it can be a serious
hazard. I almost always operate the larger forge outdoors, but I usually
use the little one on a bench inside. I installed a carbon monoxide
detector in my work area for just this reason. The CO alarm has never
gone off (the smoke detector has), but then I always keep the garage
doors open when I'm running the micro forge. You can't have too much air
outside the forge. Anyway, a CO alarm is cheap peace of mind.

Jim

Damned if i know wrote...
3/16 and especially 1/4 are far too thick.

Not in my opinion. I have made plane irons from 1/16" to 1/4" thick for a
wide variety of planes ranging from block planes to jacks, and infills
including shoulder and chariot planes, as well as dovetail and rabbetting
planes. In almost every case, a thicker iron offers superior performance.
(There are exceptions.) A notable drawback of thicker irons is that
honing time is generally increased, but this often can be countered by
using micro-bevels.

you may want to consider not tempering
back. You'll have a blade that will hold an increadible edge and be also
harder than any chisel or plane blade you have now. The blades I've made
that I have not tempered back don't show any sign of a chipping problem.

This can be true, especially if the steel doesn't attain its maximum
hardness at quench. This is because it is nearly impossible to
consistently achieve initial hardness higher than HRC 62 in O1 without
tightly controlled temperature, I.e., a heat treat furnace. If you can
hold the temperature between 1470 F and 1520 F for a 20 to 30 minute
soak, and quench properly, you can get quenched hardness of HRC 64-65
from O1 all day long. *Then* you need to temper back to 61 or 62 for a
good woodworking edge tool. If your as-quenched hardness is running in
the 61-62 range -- not unusual for forge-hardened blades -- you get less
(but still some) benefit from tempering.

To avoid warping make sure the oil you use for quenching is quite hot to the
touch.

Good advice, and often neglected. 120-140 F is about right. A candy
thermometer comes in handy for this. If you have a small volume of oil,
it will heat significantly during the quench. If you're doing multiple
tools, wait between them long enough to allow the quench to cool back
into range.

Another thing to help reduce warping, cause its a plane blade there
is no need to harden any more than the first 1 1/2

Also, warping is often more pronounced in thinner sections. Additionally,
the presence of a bevel causes some warp. The quenching technique
contributes, too.

You can take advantage of the latter to counteract the former. In
general, edge tools tend to warp so as to crown the bevel. That is, the
surface opposite the bevel will be concave. OTOH, the first portion of
the steel to hit the quench "shrinks", forming a concavity there.
Consequently, you can start the quench at the bevel in order to
counteract it's tendency to crown.

It takes some experimentation to determine the best angle at which the
tool should enter the quenchant, as well as the best agitation motion for
the tool while in the quench. Sometimes it's better to plunge with the
tool pointing straight down and then move it in the direction of the
bevel. Sometimes it's better to plunge the tool straight down, but held
at an angle so the the bevel hits the quenchant first, and then move the
tool straight up and down in the quenchant.

You can reduce the amount of warping in a thin blade by clamping the tool
between two thicker pieces of flat steel, and heat treating the whole
unit.

Cheers!

Jim

Ed Huntress wrote...
If you put up some photos, I'd like to see them.

Here ya go:

http://www.paragoncode.com/shop/micro_forge/

You may want to point out ... a reducing atmosphere generates a lot
of carbon monoxide in a hurry.

Good suggestion and I tried to follow it. Let me know if there's anything
else I can add.

Cheers!

Jim

"Jim Wilson" wrote in message
link.net...
Ed Huntress wrote...
If you put up some photos, I'd like to see them.

Here ya go:

http://www.paragoncode.com/shop/micro_forge/


Hey, thanks, Jim. Now I get it. Very clever, and it's something I should
make for myself.

Ed Huntress