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263254 Christopher Dunn <christopherdunn123@g...> 2017‑09‑07 straightening a saw
Galoots

I have an old Disston rip saw and was using it to cut some wood to
make shutters. It started decently sharp, but after a dozen or so
boards, it wasn't cutting so well. I only had a few more boards to go
and decided to power through them and sharpen the saw later. Then I
hit some wavy grain, a tooth caught, and the saw blade buckled. It
doesn't have a kink, but it's now got a permanent bend to it. If I put
a straight edge on the blade from the heel to the toe, the middle
deviates about 1/4" to 3/8".

Before beating on the blade willy nilly with a hammer, does anyone
have any suggestions for removing the bend?

Thank you,
Chris
263255 Mark Pfeifer <markpfeifer@i...> 2017‑09‑07 Re: straightening a saw
If hand bending won't work, i use a peen hammer on an anvil, striking inside the
bend (ie the concave) one tap at a time.

It's counterintuitive. You'd think you bang on the convex side to shove it back
into shape, as you would with a dent in a fender. But that doesn't work on
spring steel.

The peening spreads steel, and that spreading "pushes" out the concavity. 

Sent from my iPhone
263256 Nathan Garver-Daniels <nate.garverdaniels@g...> 2017‑09‑07 Re: straightening a saw
Chris,
   The best explanation I've seen of how this works is from Bob Smalser, in
an article posted to wkfinetools.com

http:
//trestore.wkfinetools.com/saw/strSawBlade/strSawBlade1.asp

On Thu, Sep 7, 2017 at 11:48 AM, Christopher Dunn <
christopherdunn123@g...> wrote:
263274 "Adam R. Maxwell" <amaxwell@m...> 2017‑09‑09 Re: straightening a saw
> On Sep 7, 2017, at 11:39 , Nathan Garver-Daniels 
wrote:
> 
> Chris,
>   The best explanation I've seen of how this works is from Bob Smalser, in
> an article posted to wkfinetools.com
> 
> htt
p://trestore.wkfinetools.com/saw/strSawBlade/strSawBlade1.asp <http://trestore.wk
finetools.com/saw/strSawBlade/strSawBlade1.asp>
FWIW, this has never done a damn thing for me, and I
just live with a gentle curve to the saw(s). You might
be able to retension it, but there's an art to this that
is not easily captured by reading and beating.

Adam
263275 Claudio DeLorenzi <claudio@d...> 2017‑09‑09 Re: straightening a saw
If you happen to have a 6 inch or 12 inch strip of spring steel (the blue
"shim stock" commonly sold) , try hammering the oiled surface on an oiled
anvil (ie a hard faced, ringing anvil, not the  dull thuds from the dollar
store  ones) you can watch this process work.  A straight  strip of spring
steel will turn into a C shape, convex up, as you gently hammer it.  It
does work- try it. The hammer seems to stretch the surface of the far side
(ie the down side) of the spring steel, so it will curve upwards.
Now you have to think in three dimensions though to work out how to undo
what was done to the saw in the first place.
Cheers
Claudio
263276 Nichael Cramer <nichael@s...> 2017‑09‑09 Re: straightening a saw
I remember on the WWS where Roy describe "an old technique"
for straightening a kinked blade in which you go out to a lake and
repeatedly smack the saw broadside-down on the water until
it un-kinked.

N
[Although I must admit that I always suspected  that --just maybe-- this
was the task assigned to the new apprentice the first time s/he kinked a
blade.  Then when they got back to the shop, and had a chance
to dry out a bit, they could be sent to the hardware store for a can
of tartan paint, or a dozen AC batteries.]
263277 Matthew Groves <grovesthegrey@g...> 2017‑09‑09 Re: straightening a saw
You say convex up, but talk about the far side being stretched.

Is your anvil on the ceiling? Or did you mean concave up instead?

Matthew Groves 
Springfield, MO
263280 Ed Minch <ruby1638@a...> 2017‑09‑10 Re: straightening a saw
I picked up this hammer at a garbage sale a few years ago.  At first I thought
it was a filemaker’s hammer, but then read that the domed face made it a saw
tensioner’s hammer.  Anybody have any ideas?  The other hammer is a 16 oz
clawhammer, and I think the big drop hammer weights about 2-1/2 pounds.

https://www.flickr.com/photos/ruby1638/36296276504/in/dateposted-public/


Ed Minch
263281 Claudio DeLorenzi <claudio@d...> 2017‑09‑10 Re: straightening a saw
Hi Matthew:
Oops- I mis spoke- I meant to say the strip will be concave up as you
hammer on it!  Duh.  I've been up since 4 am working on my talks because I
leave for Beijing at the crack'o'dawn and I'm no where near ready.  These
emails are a nice break from everything.

Let me try it again!  A flat strip of spring steel has two surfaces, the
one laying on the anvil, and the one facing outwards that you are going to
hammer upon.  As you hammer on the flat shim stock, the ends of the shim
stock will curl upwards, away from the anvil surface.  You can think of it
as the shim stock surface that is against the anvil is stretching out, as
Bob Smalser points out in his excellent articles.  The upper surface of the
shim stock that you are hammering (gently) upon seems to contract or
shrink, but I suspect it is mainly the underside that is expanding more as
the force vectors radiate outwards from the gently curved face of the
hammer (I'm not using the ball face of a mechanic's hammer- I'm using the
crowned face of a good older blacksmith type hammer- sharp edged flat faced
hammers are death to saws- you'll never get those marks off).  Constantly
wipe everything with an oily rag, and you have to use your best hammer
etiquette (no miss hits).

I have no floating anvils.  You have to go to Happy Camp in California for
that sort of stuff.  Scott G has several floaters in his shop, I hear.
That ain't wood smoke you see coming out of his windows.  Now you know why
it's called 'Happy Camp'.
Cheers

On Sat, Sep 9, 2017 at 10:05 AM, Matthew Groves 
wrote:
263291 "Adam R. Maxwell" <amaxwell@m...> 2017‑09‑10 Re: straightening a saw
> On Sep 9, 2017, at 17:35 , Ed Minch  wrote:
> 
> I picked up this hammer at a garbage sale a few years ago.  At first I thought
it was a filemaker’s hammer, but then read that the domed face made it a saw
tensioner’s hammer.  Anybody have any ideas?  The other hammer is a 16 oz
clawhammer, and I think the big drop hammer weights about 2-1/2 pounds.
> 
> https://www.flickr.com/photos/ruby1638/36296276504/in/dateposted-
public/ <https://www.flickr.com/photos/ruby1638/36296276504/in
/dateposted-public/>

Sounds plausible based on a google search. I just learned recently that my
grandpa worked in the saw shop at one of the local mills, and there learned how
to gum out and flatten/retension the big circular saw blades, which is probably
what that hammer was used for. I periodically see a sawmaker's anvil for sale
around here, presumably from one of those shops. Wish I'd asked grandpa about
that before he passed on, nearly 20 years ago.

Adam

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