I was happily mortising away last night with my trusty mortiser when
the bit started smoking. I really should have stopped to see what was
going on but only had two more do and it was late so I blithely
continued. The chisel/bit combo seemed to be adjusted properly but I
managed to blue it up pretty good. The chisel is a cheap one that came
with the machine ( General ). It seemed to blue very quickly. Does the
quality of the chisel have anything to do with how much heat ( i.e.
abuse ) the chisel will take? Also does anyone have any good ideas on
how to do backyard retempering? The hottest thing that I have is a
basic plumbing propane torch. I DAGS on this subject but couldn't find
anything that would suggest a plan. TIA.
Retempering can be easily done with your propane torch and a quenching
agent. A bit of time and work is involved. However if you are curious and
want to experiment some, here is a rather in depth information site that
should help. The blue color can be sanded away. Your drill bit is probably
in worse condition than the chisel. As you need only to harden the cutting
end of the chisel, It is an easy task. You can resharpen with a Dremel type
tool and fine grain pointed grinding stone. The drill bit is another story
as it would require specialized controlled heating equipment and quenching
compounds to achieve the proper hardness throughout. It would be easier to
just replace. :
http://www.orologeria.com/english/magazine/magazine5.htm
--
Chipper Wood
useours, yours won't work
"PSobon" <[email protected]> wrote in message
news:[email protected]...
> I was happily mortising away last night with my trusty mortiser when
> the bit started smoking. I really should have stopped to see what was
> going on but only had two more do and it was late so I blithely
> continued. The chisel/bit combo seemed to be adjusted properly but I
> managed to blue it up pretty good. The chisel is a cheap one that came
> with the machine ( General ). It seemed to blue very quickly. Does the
> quality of the chisel have anything to do with how much heat ( i.e.
> abuse ) the chisel will take? Also does anyone have any good ideas on
> how to do backyard retempering? The hottest thing that I have is a
> basic plumbing propane torch. I DAGS on this subject but couldn't find
> anything that would suggest a plan. TIA.
On Mon, 03 May 2004 21:41:06 -0700, Fly-by-Night CC
<[email protected]> wrote:
>In article <[email protected]>,
> Andy Dingley <[email protected]> wrote:
>
>> It's dead.
>
>Well, he could bring it back to life by rehardening and tempering it if
>it did indeed lose the hardness. Shouldn't be that difficult to do with
>a smallish chisel and a propane or MAPP torch.
IIRC high speed steel is untemperable in the home shop. it takes some
pretty sophisticated equipment....
Lee Valley describes the cause of your problem quite succinctly and
aptly in their current catalog.
"The standard problem with these sets is that users ignore the bit
setting instructions and burn both the bit and chisel because they fail
to leave the correct gap between the two. Just a little warning that if
anything turns blue you should look in the mirror to see the cause."
http://www.leevalley.com/wood/page.asp?SID=&ccurrency=1&page=41702&category=1,180,42334
It's time for a replacement chisel.
RB
PSobon wrote:
> I was happily mortising away last night with my trusty mortiser when
> the bit started smoking. I really should have stopped to see what was
> going on but only had two more do and it was late so I blithely
> continued. The chisel/bit combo seemed to be adjusted properly but I
> managed to blue it up pretty good. The chisel is a cheap one that came
> with the machine ( General ). It seemed to blue very quickly. Does the
> quality of the chisel have anything to do with how much heat ( i.e.
> abuse ) the chisel will take? Also does anyone have any good ideas on
> how to do backyard retempering? The hottest thing that I have is a
> basic plumbing propane torch. I DAGS on this subject but couldn't find
> anything that would suggest a plan. TIA.
On 3 May 2004 12:02:49 -0700, [email protected] (PSobon) wrote:
>The chisel is a cheap one that came
>with the machine ( General ). It seemed to blue very quickly.
It's dead.
I am definitely guilty of tool abuse. ( stop me before I blue again!)
I'm not really sure what kind of steel was used to make the chisel.
I was hoping that I could just throw it in the oven or hit it with a
torch to retemper it but apparently there is much more to the process
than that.
I guess in the final analysis it really doesn't matter. If bluing it
ruined the chisel then it was cheap to begin with and not much of a
loss. If it is good chisel made of HSS then bluing it doesn't matter.
This fact was something that I was not aware of. Thanks for all the
info on this question.
> I'm not really sure what kind of steel was used to make the chisel.
> I was hoping that I could just throw it in the oven or hit it with a
> torch to retemper it but apparently there is much more to the process
> than that.
> I guess in the final analysis it really doesn't matter. If bluing it
> ruined the chisel then it was cheap to begin with and not much of a
> loss. If it is good chisel made of HSS then bluing it doesn't matter.
> This fact was something that I was not aware of. Thanks for all the
> info on this question.
Probably more info than you bargained for (and much of it less than
accurate). If the tool is high speed steel, it should be able to be "blued"
without damage (though I'd consider the coloration to be a hint that
something's not right with the operation at hand -- your cutter's dull or
you're pushing it way too hard.) Resharpen it and see if it still works. If
it won't hold an edge, it's probably not HSS and will need to be rehardened
and tempered (or replaced). The problem here is that, without knowing the
exact alloy it's made from, you may or may not succeed as the procedure
differs for different steels. More at: http://www.hocktools.com/diyht.htm
about heat treatment of simple carbon steels. Good luck.
Ron Hock
HOCK TOOLS
www.hocktools.com
On Tue, 04 May 2004 07:56:54 -0700, Fly-by-Night CC
<[email protected]> wrote:
>My reply to propane it was in response to Andy who said it was a dead
>chisel. If bluing it did kill it - it would be high-carbon steel and
>that *can* be easily rehardened and tempered at home.
It's dead. It's a cheap and lousy chisel, made from cheesemetal. If
it's not capable of retaining its temper when blue (which is likely)
then it's probably already showing microcracking. No attempt to
re-harden this is going to work usefully. You might get it "hard"
again, but you aren't going to turn it back into a chisel.
If it's real HSS, you need to normalise it before trying to re-harden
it. You need an electrically controlled furnace to do this, because
you need to cool it from red heat over about 5 hours (which means
gradually reducing the heat, not just wrapping it up and letting it
cool slowly).
--
Smert' spamionam
PSobon wrote:
> I was happily mortising away last night with my trusty mortiser when
> the bit started smoking. I really should have stopped to see what was
> going on but only had two more do and it was late so I blithely
> continued. The chisel/bit combo seemed to be adjusted properly but I
> managed to blue it up pretty good. The chisel is a cheap one that came
> with the machine ( General ). It seemed to blue very quickly. Does the
> quality of the chisel have anything to do with how much heat ( i.e.
> abuse ) the chisel will take? Also does anyone have any good ideas on
> how to do backyard retempering? The hottest thing that I have is a
> basic plumbing propane torch. I DAGS on this subject but couldn't find
> anything that would suggest a plan. TIA.
If you can heat the chisel to a dull cherry-reddish color (usually right
about the time there is a sudden change in it's magnetic properties),
and then quench the tool properly, you'll be able to restore the
hardening. The quicker the steel cools, the harder it will be, because
the atoms are bouncing around like crazy and suddenly stopped before
they can align. To reharden a mortise chisel, you should dip the whole
thing wet clay repeatedly, then pare away the clay around the tip at a
step angle. This will allow the steel to cool slower as the tip is
quenched.
Heat the tool with a torch just until the tip is no longer magnetic,
then plunge into cold motor oil. You may have practice a few times
before you get the right cooling speed. You can do scratch testing on
the chisel tip to determine an acceptable level of hardness. It's really
not too difficult. If your chisel doesn't cool fast enough in in oil,
try water instead. Some people like to use dry ice, but if you try it,
be prepared for some blood curdling howling as the CO2 is converted from
frozen to gaseous state quickly.
The colors you see when the tool gets hot is caused by oxidation.
Different gasses in the environment produce different colors of
oxidation at different temperatures. If the tip is too brittle, you can
drive off some of the hardness by heating and quenching at when the
color is yellowish straw.
Good luck!
--
-linux_lad
To verify that this post isn't forged, click here:
http://www.spoofproof.org/verify.php?sig=5dd4dbd99d9e620ea8c47d52531cdc67
In article <[email protected]>,
[email protected] (PSobon) wrote:
> It seemed to blue very quickly.
If the chisel's made of high-speed steel you wouldn't have to worry
about bluing and ruining the temper. Bluing happens at a temp much lower
than would affect the hardness of high-speed steel.
--
Here's waving to ya - \||||
Owen
In article <[email protected]>,
[email protected] wrote:
> IIRC high speed steel is untemperable in the home shop. it takes some
> pretty sophisticated equipment....
Right. My first post told him that if it was HSS, then bluing it
wouldn't harm the hardness. Bluing happens at a much lower temp than
would affect the hardness of HSS. I hadn't heard back from the OP on
what the steel is - I'd almost assume it is HSS as most tooling is
nowadays, especially something like a mortising bit and chisel.
My reply to propane it was in response to Andy who said it was a dead
chisel. If bluing it did kill it - it would be high-carbon steel and
that *can* be easily rehardened and tempered at home.
--
Owen Lowe and his Fly-by-Night Copper Company
Offering a shim for the Porter-Cable 557 type 2 fence design.
<http://www.flybynightcoppercompany.com>
<http://www.easystreet.com/~onlnlowe/index.html>
In article <[email protected]>,
Andy Dingley <[email protected]> wrote:
> It's dead.
Well, he could bring it back to life by rehardening and tempering it if
it did indeed lose the hardness. Shouldn't be that difficult to do with
a smallish chisel and a propane or MAPP torch.
--
Owen Lowe and his Fly-by-Night Copper Company
Offering a shim for the Porter-Cable 557 type 2 fence design.
<http://www.flybynightcoppercompany.com>
<http://www.easystreet.com/~onlnlowe/index.html>
In article <[email protected]>,
[email protected] (PSobon) wrote:
> I am definitely guilty of tool abuse. ( stop me before I blue again!)
> I'm not really sure what kind of steel was used to make the chisel.
> I was hoping that I could just throw it in the oven or hit it with a
> torch to retemper it but apparently there is much more to the process
> than that.
> I guess in the final analysis it really doesn't matter. If bluing it
> ruined the chisel then it was cheap to begin with and not much of a
> loss. If it is good chisel made of HSS then bluing it doesn't matter.
> This fact was something that I was not aware of. Thanks for all the
> info on this question.
I guess I should have read your reply before I again responded to Andy.
If you have a grinder (or maybe a belt or disk sander) you can do a
quick test to get an idea of the type of steel in the chisel. The
characteristics of the sparks thrown off the tool give an indication as
to the steel. After leaving the abrasive, if the sparks leave in a line
and then branch and behave similar to a 4th of July sparkler then it's
likely a high-carbon steel. If the sparks are an orangish and don't
branch out - meaning they streak off the abrasive in a line and just
disappear with no additional separation then the steel is likely
high-speed. To do this test, pick an out of the way area that isn't
going to be needed for an edge or for mounting in the machine.
If it were mine, I'd just try using the chisel and seeing how the edge
holds up. -- If it dulls easily or rolls then the hardness has
definitely been compromised and you'll have to reharden it or replace
it. If it appears to behave normally and works as well as before then
it's likely HSS and you can go on your merry mortising way.
--
Owen Lowe and his Fly-by-Night Copper Company
Offering a shim for the Porter-Cable 557 type 2 fence design.
<http://www.flybynightcoppercompany.com>
<http://www.easystreet.com/~onlnlowe/index.html>
In article <[email protected]>,
Andy Dingley <[email protected]> wrote:
> If it's real HSS, you need to normalise it before trying to re-harden
> it. You need an electrically controlled furnace to do this, because
> you need to cool it from red heat over about 5 hours (which means
> gradually reducing the heat, not just wrapping it up and letting it
> cool slowly).
But if it is real HSS, then bluing it wouldn't have affected it's
edgeholding ability anyway so no remedies are necessary. I agree that if
it's of the high-carbon variety, then the OP might be better served in
replacing it with a HSS version just for longevity's sake. But that's
not to say that a softened high-carbon chisel can't be brought back to
useable condition in the home shop. (I agree HSS is a different and much
more difficult animal to tame with home shop tools.)
If the chisel is not marked as HSS, then to settle this, the OP would
need to do a spark test on the upper section of the square portion to
really see what he's got and if any remedies are in order.
--
Owen Lowe and his Fly-by-Night Copper Company
Offering a shim for the Porter-Cable 557 type 2 fence design.
<http://www.flybynightcoppercompany.com>
<http://www.easystreet.com/~onlnlowe/index.html>