It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild
steel would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel
and hard steel have the same tensile strength, right? Or, is it a
matter of yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have
very specific geometry, so store-bought is not an option.)

Thanks,
Bob

"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild steel
would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel and
hard steel have the same tensile strength, right? Or, is it a matter of
yield verses ultimate strength?

Not-bending as in a spring is a function of stiffness. Not-bending as in
taking a permanent set is a matter of yield strength.

They have the same *stiffness* -- Young's modulus. Their yield strengths
differ greatly, and their tensile strengths do, too, in rough proportion to
their relative yield strength.


Bottom line - what should I use use to make a pry bar? (It will have very
specific geometry, so store-bought is not an option.)

It depends on how big it is and what heat treating facilities you have.

--
Ed Huntress

Bob Engelhardt wrote:
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild
steel would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel
and hard steel have the same tensile strength, right? Or, is it a
matter of yield verses ultimate strength?

Tensile strength -- AFAIK this is a vague term vs. yield and ultimate
strength.

yield strength -- the 'tensile strength' at which the material begins to
permanently deform.

ultimate strength -- the 'tensile strength' at which the material
really-o truly-o breaks.

Mild and medium steels have different yield and ultimate strengths, more
or less related by elongation. Hard steels, and other brittle materials
like glass, stone, ceramic, etc., don't elongate, so their yield and
ultimate strengths are the same tensile strength.

You left out the Young's modulus, which, together with the dimensions of
the piece, determine the spring rate. _This_ is the thing that is
practically the same between mild and hard steel. It's what says "if
you stress it so much, it'll deform so much, if you stress it twice as
hard, it'll deform twice as much" -- as long as nothing's getting
permanently bent.

Bottom line - what should I use use to make a pry bar? (It will have
very specific geometry, so store-bought is not an option.)

Something that won't bend easily, but _will_ bend before it breaks. You
don't want it to just go "blorp" when you stress it, but you'd much
rather it bends when you're really reefing on it than to have it snap
with a ton of force behind the little bits that are still prying.

Model T Ford drive shafts make superlative pry bars, for just this reason.

As Ed alluded, it's going to be hard to make a pry bar without heat
treating facilities. I rather suspect that you want to start with
material in an annealed condition and/or bend it up using heat -- but
then you need to harden the thing, which means that you have to get the
whole mess up to a uniform temperature and quench it. And that wouldn't
be easy.

If you just need the "handle" end to have weird kinks, but the
"business" end can be normal pry bar, consider bending a normal pry bar
to shape (with generous use of a rosebud torch). You'll lose temper at
the bends, but if they're not as stressed as the ends maybe you'll get
away with it.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

On Mar 18, 1:51*pm, Bob Engelhardt wrote:
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). *But it doesn't seem to me (by intuition ONLY) that mild
steel would be "strong" enough. *It seems like it would bend too easily..

But not-bending is a matter of tensile strength, yes? *And mild steel
and hard steel have the same tensile strength, right? *Or, is it a
matter of yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? *(It will have
very specific geometry, so store-bought is not an option.)

Thanks,
Bob

I think a big question is, what are the dimensions?
What I see called a 'pry bar' covers a pretty big area, from thin and
wide (carpentry) to something more akin to a crowbar.

My thin carpentry ones seem to have a bit of carbon in them, given the
sparks they give off when I sharpen them.

Dave

Ford model T driveshafts may be a little hard to find these days.
Actually you can use Ford driveshafts made up to 1948.
They were solid bars about 1" in diameter and operated in a housing.
This housing, called a torque tube resisted the torque reaction of the
rear end housing, rather than depending on the springs.
I wish Fords were that well built these days.
I have used these driveshafts for such things as unscrewing the chuck
from a 17" lathe after it had been on for about 30 years, also prying
the tracks back on a caterpillar.
They are very difficult to bend and I've never seen one break.
I have made a lot of parts feom the steel, it can be machined with
difficulty as is and will oil harden to file hardness.

Engineman

On Mar 18, 12:02�pm, Tim Wescott wrote:
Bob Engelhardt wrote:
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). �But it doesn't seem to me (by intuition ONLY) that mild
steel would be "strong" enough. �It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? �And mild steel
and hard steel have the same tensile strength, right? �Or, is it a
matter of yield verses ultimate strength?

Tensile strength -- AFAIK this is a vague term vs. yield and ultimate
strength.

yield strength -- the 'tensile strength' at which the material begins to
permanently deform.

ultimate strength -- the 'tensile strength' at which the material
really-o truly-o breaks.

Mild and medium steels have different yield and ultimate strengths, more
or less related by elongation. �Hard steels, and other brittle materials
like glass, stone, ceramic, etc., don't elongate, so their yield and
ultimate strengths are the same tensile strength.

You left out the Young's modulus, which, together with the dimensions of
the piece, determine the spring rate. �_This_ is the thing that is
practically the same between mild and hard steel. �It's what says "if
you stress it so much, it'll deform so much, if you stress it twice as
hard, it'll deform twice as much" -- as long as nothing's getting
permanently bent.

Bottom line - what should I use use to make a pry bar? �(It will have
very specific geometry, so store-bought is not an option.)

Something that won't bend easily, but _will_ bend before it breaks. �You
don't want it to just go "blorp" when you stress it, but you'd much
rather it bends when you're really reefing on it than to have it snap
with a ton of force behind the little bits that are still prying.

Model T Ford drive shafts make superlative pry bars, for just this reason..

As Ed alluded, it's going to be hard to make a pry bar without heat
treating facilities. �I rather suspect that you want to start with
material in an annealed condition and/or bend it up using heat -- but
then you need to harden the thing, which means that you have to get the
whole mess up to a uniform temperature and quench it. �And that wouldn't
be easy.

If you just need the "handle" end to have weird kinks, but the
"business" end can be normal pry bar, consider bending a normal pry bar
to shape (with generous use of a rosebud torch). �You'll lose temper at
the bends, but if they're not as stressed as the ends maybe you'll get
away with it.

--
Tim Wescott
Control system and signal processing consultingwww.wescottdesign.com

On 2010-03-18, Steve B wrote:

"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild steel
would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel and
hard steel have the same tensile strength, right? Or, is it a matter of
yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have very
specific geometry, so store-bought is not an option.)

Thanks,
Bob

I will not offer any advice on how to do that. You will hear from those who
know how to make it stiff.

My comment is: Give it to me for half an hour. I'll find out if it can be
bent. I haven't met one yet that I couldn't bend. And mostly by taking
them outside their limits.

Steve



Can you bend them without using pipe extensions?

i

Ignoramus18751 wrote:
On 2010-03-18, Steve B wrote:

"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no
cutting involved). But it doesn't seem to me (by intuition ONLY)
that mild steel would be "strong" enough. It seems like it would
bend too easily.

But not-bending is a matter of tensile strength, yes? And mild
steel and hard steel have the same tensile strength, right? Or, is
it a matter of yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will
have very specific geometry, so store-bought is not an option.)

Thanks,
Bob

I will not offer any advice on how to do that. You will hear from
those who know how to make it stiff.

My comment is: Give it to me for half an hour. I'll find out if it
can be bent. I haven't met one yet that I couldn't bend. And
mostly by taking them outside their limits.

Steve



Can you bend them without using pipe extensions?

i

I can and have . And I'm not a very big guy , I only weigh around 150 - up
from 127-132 five years ago when I quit smoking . (actually 10:03 PM on the
21st will be 5 yrs) .

--
Snag
"90 FLHTCU "Strider"
'39 WLDD "PopCycle"
BS 132/SENS/DOF

"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild steel
would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel and
hard steel have the same tensile strength, right? Or, is it a matter of
yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have very
specific geometry, so store-bought is not an option.)

Thanks,
Bob

I will not offer any advice on how to do that. You will hear from those who
know how to make it stiff.

My comment is: Give it to me for half an hour. I'll find out if it can be
bent. I haven't met one yet that I couldn't bend. And mostly by taking
them outside their limits.

Steve

"Bob Engelhardt" wrote

Bottom line - what should I use use to make a pry bar? (It will have very
specific geometry, so store-bought is not an option.)

Thanks,
Bob

From what I know, it's not what you make it out of (well, not totally), but
how you heat and cool it afterward that makes it stiff.

Steve

"Ignoramus18751" wrote in message
...
On 2010-03-18, Steve B wrote:

"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild
steel
would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel
and
hard steel have the same tensile strength, right? Or, is it a matter of
yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have
very
specific geometry, so store-bought is not an option.)

Thanks,
Bob

I will not offer any advice on how to do that. You will hear from those
who
know how to make it stiff.

My comment is: Give it to me for half an hour. I'll find out if it can
be
bent. I haven't met one yet that I couldn't bend. And mostly by taking
them outside their limits.

Steve



Can you bend them without using pipe extensions?

i

I have, yes. When I was younger. I bent one recently straightening it by
putting a hydraulic jack on it.

Steve

"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild steel
would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel and
hard steel have the same tensile strength, right? Or, is it a matter of
yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have very
specific geometry, so store-bought is not an option.)

Thanks,
Bob

Want an easy answer that should work? order 4140 from Mcmaster carr. Comes
in most any size you need. heat treating it with a torch and oil quench will
make it far stronger.

Karl

Ignoramus18751 wrote:

Can you bend them without using pipe extensions?


I've broke them without a pip but that is due to Far east heat cheating.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild steel
would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel and
hard steel have the same tensile strength, right? Or, is it a matter of
yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have very
specific geometry, so store-bought is not an option.)

Thanks,
Bob

I've seen one made from a truck leaf spring. Also, farm cultivator blades. I
think it's called that, it has knife like projections on the bottom. They
may be medium carbon steel shanks with hardened tips. The tips are sometimes
given a powder coat of tungsten or similar hard face.

On Thu, 18 Mar 2010 13:51:53 -0400, the infamous Bob Engelhardt
scrawled the following:

It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild
steel would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel
and hard steel have the same tensile strength, right? Or, is it a
matter of yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have
very specific geometry, so store-bought is not an option.)

Oh, a likely story, Bob.

And just how are you going to teach geometry to a steel bar, hmm?

Seriousity mode: ON

I don't have any answers, but I do have more questions (some that a
person who knows steel will want answers to, too.) I have at least 5
different types of pry bars, all for different uses, all made of
different steels, and all hardened and tempered differently.

What type of prying will you be doing?
Do you want any spring to it at all? If so, how much?
How thin does it need to be at the point of highest leverage?
How big will it be? 2"? 2'? 2 meters? @ what diameter/hex?
Will you pound on it with a hammer?
What kind of abrasion will it see?
At what temp will it be used?
On what material will it be used?
(end of quick list)

I'm sure that we're both guessing that the tougher steels would get
the nod and that hardening plays an important part in the picture.

--
No matter how cynical you are, it is impossible to keep up.
--Lily Tomlin

On Thu, 18 Mar 2010 13:07:19 -0700 (PDT), the infamous engineman
scrawled the following:

Ford model T driveshafts may be a little hard to find these days.
Actually you can use Ford driveshafts made up to 1948.
They were solid bars about 1" in diameter and operated in a housing.
This housing, called a torque tube resisted the torque reaction of the
rear end housing, rather than depending on the springs.
I wish Fords were that well built these days.
I have used these driveshafts for such things as unscrewing the chuck
from a 17" lathe after it had been on for about 30 years, also prying
the tracks back on a caterpillar.
They are very difficult to bend and I've never seen one break.
I have made a lot of parts feom the steel, it can be machined with
difficulty as is and will oil harden to file hardness.

I had a section of green Chrysler torsion bar which i used as a pry
bar for years. It somehow didn't make the move with me to Oregon.

It would spring just a hair with me on the end and a about a ton of
weight leveraged at 2". I sorely miss it. It would have made a good
digging bar in my current work.

--
No matter how cynical you are, it is impossible to keep up.
--Lily Tomlin

OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

"Bob Engelhardt" wrote in message
...
OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability is
propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials with
a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob


I'm going to bow out of discussing making this one from scratch because
there are a lot of unknowns, and I'd only be guessing. I will offer a couple
of thoughts on another approach, though.

First, what you're describing sounds quite a bit like a Red Devil pry bar
that I have -- my thinnest one, which is tapered very thin, about 1-1/2"
wide, and really strong. But it's only about 12" long and would have to be
bent near the end, which probably would leave it a lot *less* strong after
softening with a torch and a half-fast re-heat-treatment. That can be
tricky, depending on the alloy.

But if you could find one of those things you probably could drill a couple
of holes in it and screw on a longer handle. We can discuss spot-annealing
with a drill press if necessary.

I'd start with something already made if at all possible. It's not that you
need great strength, it's just that you're otherwise dealing with more
variables than it's worth.

Good luck.

--
Ed Huntress

On 2010-03-19, Bob Engelhardt wrote:
OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

Do you have a firepit?

i

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

Ignoramus18751 wrote:
On 2010-03-18, Steve B wrote:
"Bob Engelhardt" wrote in message
...
It doesn't have to be hard in the sense of holding an edge (no cutting
involved). But it doesn't seem to me (by intuition ONLY) that mild steel
would be "strong" enough. It seems like it would bend too easily.

But not-bending is a matter of tensile strength, yes? And mild steel and
hard steel have the same tensile strength, right? Or, is it a matter of
yield verses ultimate strength?

Bottom line - what should I use use to make a pry bar? (It will have very
specific geometry, so store-bought is not an option.)

Thanks,
Bob
I will not offer any advice on how to do that. You will hear from those who
know how to make it stiff.

My comment is: Give it to me for half an hour. I'll find out if it can be
bent. I haven't met one yet that I couldn't bend. And mostly by taking
them outside their limits.

Steve



Can you bend them without using pipe extensions?

i

I can and do with alarming regularity! I have my own collection of bent
bars, from small flat bars up through halligan tools. Those get a bit
expensive!!!

--
Steve W.

Bob Engelhardt wrote:
OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob


I think I would try using a clamp style nail puller on a slide hammer to
remove the nails. Less damage to the tin and probably much faster. I
would probably take a set of vice grips, weld a set of tapered jaws on
the end to grip under the nail head. Then attach that to a slide hammer.

Tin is VERY, VERY easy to damage. BTDT working on a church kitchen
ceiling. Decided that decorative tin is WAY to much trouble...

--
Steve W.

4140 heat treated to about Rc45

On Mar 18, 10:16*pm, "Ed Huntress" wrote:
...
First, what you're describing sounds quite a bit like a Red Devil pry bar
...
Ed Huntress

I have several of that type and the gooseneck variant in different
sizes that I ground thin and belt-sanded smooth to loosen trim and
pull nails. Dark blue import ones that cost $3 have held up well for
this or other projects that needed a little chunk of hardened flat bar
stock.
http://www.platatac.com/www/182/file...devil-tool.jpg

jsw

Bob Engelhardt wrote:
OK, from what Ed & Tim said, I do want something harder than mild
steel, so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat
capability is propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The
ceilings will be salvaged, so the specifics of the tool are needed
to minimize damage. The bar needs to be about 16" long, to reach
over the back of a 24" tile. It needs to have a long taper, coming
to a thin edge, to work under the nails without distorting the tin. One
edge needs to be 3/4" wide to fit into a nailing space. One end
will be straight & the other have a 90 degree leg. It will be
pulling out 1" long 16 ga nails, so it won't have to be very strong -
I'm thinking 1/16" thick (from trials with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

Sounds a lot like the beekeepers little pry I have . They use it to loosen
the frames in a hive , and except for the length fits your description .
Have you looked at the "wonder bar" flat prybars ? They also fit your
description ...

--
Snag
"90 FLHTCU "Strider"
'39 WLDD "PopCycle"
BS 132/SENS/DOF

On Mar 18, 9:58*pm, Bob Engelhardt wrote:
OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. *Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. *The ceilings
* will be salvaged, so the specifics of the tool are needed to minimize
damage. *The bar needs to be about 16" long, to reach over the back of a
24" tile. *It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. *One edge needs to be 3/4"
wide to fit into a nailing space. *One end will be straight & the other
have a 90 degree leg. *It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. *Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? *How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

Maybe you could modify a shingle ripper into a pry bar, since the
prying force will be pretty low.

Seems like getting the pry bar in there, then getting a fulcrum in
near it might get the nails out with a straighter pull?

Bar in, pull bar down a little, insert fulcrum (on a longish handle),
then push bar up towards the ceiling.


Dave

On Fri, 19 Mar 2010 01:49:40 -0400, the infamous "Steve W."
scrawled the following:

Bob Engelhardt wrote:
OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob


I think I would try using a clamp style nail puller on a slide hammer to
remove the nails. Less damage to the tin and probably much faster. I
would probably take a set of vice grips, weld a set of tapered jaws on
the end to grip under the nail head. Then attach that to a slide hammer.

Not a bad idea.


Tin is VERY, VERY easy to damage. BTDT working on a church kitchen
ceiling. Decided that decorative tin is WAY to much trouble...

It sure is when idiots install them with 2-1/2" 8-pennies. BTDT twice
(one alum/tin ceiling panel, one stainless backsplash demo which I'd
hoped to save but couldn't), damnear cursed the things out. Once I got
a tiny bit of movement, I could get the needlenose vise grips onto the
heads. I then twisted and pulled them out without any more damage.
Bob's springsteel remover wouldn't have helped, even if 1/8" thick.

Bob, how about something in the way of a wedge? Dual jaws with a
little tongue which pushes them apart? I'll bet that if you can come
up with something like that, you could sell them to metal shops.
You'll be rich!

--
Adults are obsolete children. --Dr. Seuss (Theodore Geisel, 1904-1991)
--

On Thu, 18 Mar 2010 21:58:50 -0400, Bob Engelhardt
wrote:

OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

http://www.amazon.com/b?ie=UTF8&node=553310



"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

On Fri, 19 Mar 2010 05:21:38 -0700 (PDT), Dave__67
wrote:

On Mar 18, 9:58*pm, Bob Engelhardt wrote:
OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. *Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. *The ceilings
* will be salvaged, so the specifics of the tool are needed to minimize
damage. *The bar needs to be about 16" long, to reach over the back of a
24" tile. *It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. *One edge needs to be 3/4"
wide to fit into a nailing space. *One end will be straight & the other
have a 90 degree leg. *It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. *Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? *How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

Maybe you could modify a shingle ripper into a pry bar, since the
prying force will be pretty low.

Seems like getting the pry bar in there, then getting a fulcrum in
near it might get the nails out with a straighter pull?

Bar in, pull bar down a little, insert fulcrum (on a longish handle),
then push bar up towards the ceiling.


Dave

Just use a slate ripper as is. shouldn't do too much damage to the tin with
16ga nails.

Mark Rand
RTFM

On Fri, 19 Mar 2010 13:36:09 -0700, the infamous Gunner Asch
scrawled the following:

On Thu, 18 Mar 2010 21:58:50 -0400, Bob Engelhardt
wrote:

OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

http://www.amazon.com/b?ie=UTF8&node=553310

Are you pointing out how many pry/crow/nail-bars there are in
existence, mon?

Bob, how about trying a shingle ripper? Throw a pair of vise grips
around the end of the flat at the handle and you have yourself a pry
bar for tin ceiling tiles. Why reinvent the wheel?

--
Adults are obsolete children. --Dr. Seuss (Theodore Geisel, 1904-1991)
--

On Fri, 19 Mar 2010 18:49:44 -0700, Larry Jaques
wrote:

On Fri, 19 Mar 2010 13:36:09 -0700, the infamous Gunner Asch
scrawled the following:

On Thu, 18 Mar 2010 21:58:50 -0400, Bob Engelhardt
wrote:

OK, from what Ed & Tim said, I do want something harder than mild steel,
so that it won't "yield" as soon as mild steel would.

As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

As to what I'm making: it's for taking down tin ceilings. The ceilings
will be salvaged, so the specifics of the tool are needed to minimize
damage. The bar needs to be about 16" long, to reach over the back of a
24" tile. It needs to have a long taper, coming to a thin edge, to work
under the nails without distorting the tin. One edge needs to be 3/4"
wide to fit into a nailing space. One end will be straight & the other
have a 90 degree leg. It will be pulling out 1" long 16 ga nails, so it
won't have to be very strong - I'm thinking 1/16" thick (from trials
with a 1/16" thick putty knife).

If it wasn't for the length, I would re-shape the putty knife. Which
suggests brazing or silver soldering the knife on a longer handle - is
that doable? How about a 90 bend in it - I assume that would require
heating to bend, quenching, and tempering?

Thanks,
Bob

http://www.amazon.com/b?ie=UTF8&node=553310

Are you pointing out how many pry/crow/nail-bars there are in
existence, mon?

Ayup..figured he might see something that flipped his kilt up.

Bob, how about trying a shingle ripper? Throw a pair of vise grips
around the end of the flat at the handle and you have yourself a pry
bar for tin ceiling tiles. Why reinvent the wheel?

--
Adults are obsolete children. --Dr. Seuss (Theodore Geisel, 1904-1991)


"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost

Ed Huntress wrote:
....
First, what you're describing sounds quite a bit like a Red Devil pry bar
that I have -- my thinnest one, which is tapered very thin, about 1-1/2"
wide, and really strong. ...

Like so?
http://tinyurl.com/ycv3vdg

I'd start with something already made if at all possible. It's not that you
need great strength, it's just that you're otherwise dealing with more
variables than it's worth.

I'm beginning to think that starting with something like the Red Devil
is the right way to go. But that some customization is likely. One
problem is that there are a LOT of pry bars online, but I'd really like
to put my hands on them and the best local hardware store doesn't have
that many.

Thanks,
Bob

Jim Wilkins wrote:
....
Dark blue import ones that cost $3 have held up well for
this or other projects that needed a little chunk of hardened flat bar
stock.

I'd like to find some $3 ones to play with. At the hardware store the
nice ones are $12 & others $7-8-9.

Bob

Ignoramus18751 wrote:
On 2010-03-19, Bob Engelhardt wrote:
....
As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

Do you have a firepit?

No, would that be better than a propane forge? Bob

Steve W. wrote:
I think I would try using a clamp style nail puller on a slide hammer to
remove the nails. Less damage to the tin and probably much faster. I
would probably take a set of vice grips, weld a set of tapered jaws on
the end to grip under the nail head. Then attach that to a slide hammer.

I'm skeptical - I think that getting under the nail head would be more
time consuming than getting behind the tin. Here's a picture of a
sharpened pry bar getting behind the tin. The arrow points to a nail head!

Tin is VERY, VERY easy to damage. BTDT working on a church kitchen
ceiling. Decided that decorative tin is WAY to much trouble...

It certainly is a lot of trouble! Today we discovered that some
ceilings have gotten wet and the nails rusted. The heads come off or
the tin tears before the nails pull out. !&%$#(!

We are being motivated by the high prices this stuff brings from the
yuppies. And it's volunteer labor being used G. There's a limit,
though, so we'll see how far it goes.

Bob

Larry Jaques wrote:
...
Bob, how about something in the way of a wedge? Dual jaws with a
little tongue which pushes them apart?

Maybe. But we're using bars sharpened to almost knife edge to get in
without distorting the tin too much. Two jaws might make it too thick.
I'll think about it.

I'll bet that if you can come
up with something like that, you could sell them to metal shops.
You'll be rich!

I'll leave that to you - ambition did not follow me into retirement,
thank goodness.

Bob

Dave__67 wrote:

Maybe you could modify a shingle ripper into a pry bar, since the
prying force will be pretty low.

I have a shingle ripper & it's much too thick & blunt. A sledge hammer
for my tack hammer job

Seems like getting the pry bar in there, then getting a fulcrum in
near it might get the nails out with a straighter pull?

Bar in, pull bar down a little, insert fulcrum (on a longish handle),
then push bar up towards the ceiling.

I like that. The fulcrum could be a 1/4" rod with a 90 degree leg.
Usually we can pull down to loosen, but if the bar isn't far enough in
it doesn't work.

Thanks
Bob

"Bob Engelhardt" wrote in message
...
Ed Huntress wrote:
...
First, what you're describing sounds quite a bit like a Red Devil pry bar
that I have -- my thinnest one, which is tapered very thin, about 1-1/2"
wide, and really strong. ...

Like so?
http://tinyurl.com/ycv3vdg

That's the one. It's served me well for around 20 years. It fits right
between a thick putty knife and my Stanley flat pry bar in thickness and
strength, and it gets a lot of use. I used it to pry off the lap siding on
one entire side of my house, and it didn't damage that 80-year-old cedar.


I'd start with something already made if at all possible. It's not that
you need great strength, it's just that you're otherwise dealing with
more variables than it's worth.

I'm beginning to think that starting with something like the Red Devil is
the right way to go. But that some customization is likely. One problem
is that there are a LOT of pry bars online, but I'd really like to put my
hands on them and the best local hardware store doesn't have that many.

Thanks,
Bob

Well, I hope you find one of those Red Devils or equivalent, because my
feeling is that it sounds about right for the basis for a thin pry bar as
you've described. I might try to torch it and bend it, but I think I'd just
try cutting a piece off with an abrasive wheel, spot-annealing a couple of
spots for drilling, and then drill a couple of holes for bolts through a
thicker piece of steel that would serve as a handle.

Easier said than done. g

--
Ed Huntress

On 2010-03-21, Bob Engelhardt wrote:
Ignoramus18751 wrote:
On 2010-03-19, Bob Engelhardt wrote:
...
As to heat treating facilities, well, minimal - maximum heat capability
is propane forge. Obviously no automatic temp control.

Do you have a firepit?

No, would that be better than a propane forge? Bob

I have a firepit that I use, mostly, for burning cut-up pallets and
cooking hot dogs. I could heat some rather big things to red heat in
it. You need about 2 pallets for that. A comparable size propane forge
would be expensive. I have a small propane forge, with which I am very
happy.

i

Gunner Asch wrote:
[for a gazillion pry bars]
http://www.amazon.com/b?ie=UTF8&node=553310

But not a one long enough & thin enough & straight.

Thanks anyhow,
Bob

BTW - this wouldn't get our nails out, but it's really cool & I want one:
http://www.amazon.com/inch-Nail-Hunt...9142218&sr=1-3

Larry Jaques wrote:

... Why reinvent the wheel?

'Cause I need a wheel with a very large diameter AND narrow tread AND a
hub to fit a specific axle stub.

Bob

Bob Engelhardt wrote:
... Here's a picture of a
sharpened pry bar getting behind the tin. The arrow points to a nail head!
[no picture link]

Sorry - here it is:
http://home.comcast.net/~bobengelhardt/TinCeiling.jpg

Bob