Help soldering broken bandsaw blade
 

"Artemus" wrote:

Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to about
45 degrees and cleaned the ends with sandpaper. I put on plenty
of flux and wedged a small piece of silver solder in the scarf joint.


Silver solder (low silver content) or silver braze (high silver content)?

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

Help soldering broken bandsaw blade
 

Wes wrote:
"Artemus" wrote:

Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to about
45 degrees and cleaned the ends with sandpaper. I put on plenty
of flux and wedged a small piece of silver solder in the scarf joint.


Silver solder (low silver content) or silver braze (high silver content)?

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


Ill come in here,
Ive silver brazed my band saw lades for 40 yrs.
as linked, the scarf joint needs to be minimum 3/8ths in long, you do
this scarfing on the top wheel of a band sander set up vertically.
Jig as also described, but bend the lower blade end up a little and he
top blade down a little.
You need to use a 50% if you can get it silver solder in foil form, 5
to 10/1000 in thick. cut a piece exactly to size, place between the 2
blade ends. mx up some easyflo flux paste preferrably s/steel grade,
apply arround the joint area. heat gently till the flux goes clear,
continue to heat till the joint goes a dull red under the flux and the
silver solder flows to wet the scarf area. allow to cool clowly.
Remove from jig, fftle up and grind both sides of blade so that the
thickness is the same overall, as you said .025 thick.
dont over tension the saw blade.
Hope this helps.
Ted. Dorset UK.

Help soldering broken bandsaw blade
 

Ted Frater wrote:

Wes wrote:
"Artemus" wrote:

Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to about
45 degrees and cleaned the ends with sandpaper. I put on plenty
of flux and wedged a small piece of silver solder in the scarf joint.


Silver solder (low silver content) or silver braze (high silver content)?

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


Ill come in here,
Ive silver brazed my band saw lades for 40 yrs.
as linked, the scarf joint needs to be minimum 3/8ths in long, you do
this scarfing on the top wheel of a band sander set up vertically.
Jig as also described, but bend the lower blade end up a little and he
top blade down a little.
You need to use a 50% if you can get it silver solder in foil form, 5
to 10/1000 in thick. cut a piece exactly to size, place between the 2
blade ends. mx up some easyflo flux paste preferrably s/steel grade,
apply arround the joint area. heat gently till the flux goes clear,
continue to heat till the joint goes a dull red under the flux and the
silver solder flows to wet the scarf area. allow to cool clowly.
Remove from jig, fftle up and grind both sides of blade so that the
thickness is the same overall, as you said .025 thick.
dont over tension the saw blade.
Hope this helps.
Ted. Dorset UK.

If you don't have foil, a clean hammer face and anvil surface can make some foil for you
with a blow or two. :)

Wes

Help soldering broken bandsaw blade
 

"Ted Frater" wrote in message
...
Wes wrote:
"Artemus" wrote:

Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to about
45 degrees and cleaned the ends with sandpaper. I put on plenty
of flux and wedged a small piece of silver solder in the scarf joint.


Silver solder (low silver content) or silver braze (high silver content)?

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


Ill come in here,
Ive silver brazed my band saw lades for 40 yrs.
as linked, the scarf joint needs to be minimum 3/8ths in long, you do
this scarfing on the top wheel of a band sander set up vertically.
Jig as also described, but bend the lower blade end up a little and he
top blade down a little.
You need to use a 50% if you can get it silver solder in foil form, 5
to 10/1000 in thick. cut a piece exactly to size, place between the 2
blade ends. mx up some easyflo flux paste preferrably s/steel grade,
apply arround the joint area. heat gently till the flux goes clear,
continue to heat till the joint goes a dull red under the flux and the
silver solder flows to wet the scarf area. allow to cool clowly.
Remove from jig, fftle up and grind both sides of blade so that the
thickness is the same overall, as you said .025 thick.
dont over tension the saw blade.
Hope this helps.
Ted. Dorset UK.

That's kind of what I was thinking to make the scarfs. Thanks.
I don't have an OE torch. Can I use propane with the 50% silver solder?
Mapp? Mapp/oxy?
Art

Help soldering broken bandsaw blade
 

Artemus wrote:
"Ted Frater" wrote in message
...
Wes wrote:
"Artemus" wrote:

Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to
about 45 degrees and cleaned the ends with sandpaper. I put on
plenty
of flux and wedged a small piece of silver solder in the scarf
joint.


Silver solder (low silver content) or silver braze (high silver
content)?

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


Ill come in here,
Ive silver brazed my band saw lades for 40 yrs.
as linked, the scarf joint needs to be minimum 3/8ths in long, you do
this scarfing on the top wheel of a band sander set up vertically.
Jig as also described, but bend the lower blade end up a little and
he top blade down a little.
You need to use a 50% if you can get it silver solder in foil
form, 5 to 10/1000 in thick. cut a piece exactly to size, place
between the 2 blade ends. mx up some easyflo flux paste preferrably
s/steel grade, apply arround the joint area. heat gently till the
flux goes clear, continue to heat till the joint goes a dull red
under the flux and the silver solder flows to wet the scarf area.
allow to cool clowly.
Remove from jig, fftle up and grind both sides of blade so that the
thickness is the same overall, as you said .025 thick.
dont over tension the saw blade.
Hope this helps.
Ted. Dorset UK.

That's kind of what I was thinking to make the scarfs. Thanks.
I don't have an OE torch. Can I use propane with the 50% silver
solder? Mapp? Mapp/oxy?
Art

For a piece that small your propane torch should work . Dad silversoldered
that way - though not bandsaw blades . Bigger pieces he put on mom's gas
range plus the torch .

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

Help soldering broken bandsaw blade
 

On Fri, 11 Jun 2010 03:59:19 +0100, Ted Frater
wrote:

Wes wrote:
"Artemus" wrote:

Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to about
45 degrees and cleaned the ends with sandpaper. I put on plenty
of flux and wedged a small piece of silver solder in the scarf joint.


Silver solder (low silver content) or silver braze (high silver content)?

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


Ill come in here,
Ive silver brazed my band saw lades for 40 yrs.
as linked, the scarf joint needs to be minimum 3/8ths in long, you do
this scarfing on the top wheel of a band sander set up vertically.
Jig as also described, but bend the lower blade end up a little and he
top blade down a little.
You need to use a 50% if you can get it silver solder in foil form, 5
to 10/1000 in thick. cut a piece exactly to size, place between the 2
blade ends. mx up some easyflo flux paste preferrably s/steel grade,
apply arround the joint area. heat gently till the flux goes clear,
continue to heat till the joint goes a dull red under the flux and the
silver solder flows to wet the scarf area. allow to cool clowly.
Remove from jig, fftle up and grind both sides of blade so that the
thickness is the same overall, as you said .025 thick.
dont over tension the saw blade.
Hope this helps.
Ted. Dorset UK.

Here's a source of 56% silver solder in foil form:
http://www.brownells.com/.aspx/pid=5..._SILVER_SOLDER

This alloy flows freely at 1205F (652C), which is a dull red.

If your propane torch will get your workpiece to red heat, it is
sufficient. It's easy to overheat when silver brazing. Patience is
a good thing.

Get some "black flux" at a welding store. Other silver-brazing fluxes
will work, but black flux tolerates overheating which most beginners
do because they get impatient.

Help soldering broken bandsaw blade
 

On Thu, 10 Jun 2010 23:03:07 -0500, "Snag"
wrote:

Artemus wrote:


That's kind of what I was thinking to make the scarfs. Thanks.
I don't have an OE torch. Can I use propane with the 50% silver
solder? Mapp? Mapp/oxy?
Art

For a piece that small your propane torch should work . Dad silversoldered
that way - though not bandsaw blades . Bigger pieces he put on mom's gas
range plus the torch .
I have been using a propane "Turbo Torch" for silver brazing for many
years. I think that the largest Item I ever did was a 4" brass drain
elbow joined to a toilet floor flange - I had to cut both pieces to
reduce the cover (concrete floor) over the top of the pipe to less
than an inch. The home owner had attempted to instal the toilet on top
of the stub left by the original construction contractor then brought
home another bag of "sack crete" every night to raise the floor up to
support the toilet - WHAT A F * * * *D UP MESS !
Gerry :-)}
London, Canada

Help soldering broken bandsaw blade
 

On Fri, 11 Jun 2010 03:59:19 +0100, Ted Frater
wrote:

Wes wrote:
"Artemus" wrote:

Obviously I'm doing something wrong here as my joints are brittle
and don't hold worth squat. I ground the ends of the blade to about
45 degrees and cleaned the ends with sandpaper. I put on plenty
of flux and wedged a small piece of silver solder in the scarf joint.


Silver solder (low silver content) or silver braze (high silver content)?

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


Ill come in here,
Ive silver brazed my band saw lades for 40 yrs.
as linked, the scarf joint needs to be minimum 3/8ths in long, you do
this scarfing on the top wheel of a band sander set up vertically.
Jig as also described, but bend the lower blade end up a little and he
top blade down a little.
You need to use a 50% if you can get it silver solder in foil form, 5
to 10/1000 in thick. cut a piece exactly to size, place between the 2
blade ends. mx up some easyflo flux paste preferrably s/steel grade,
apply arround the joint area. heat gently till the flux goes clear,
continue to heat till the joint goes a dull red under the flux and the
silver solder flows to wet the scarf area. allow to cool clowly.
Remove from jig, fftle up and grind both sides of blade so that the
thickness is the same overall, as you said .025 thick.
dont over tension the saw blade.
Hope this helps.
Ted. Dorset UK.

I've also silver brazed my blades for many years but slightly
differently.

The 30 deg bevelled blades are held in a simple open jig with
small G clamps.

An 0.005" feeler gauge (subsequently withdrawn) spaces the two
ends to provide a proper capillary gap.

The gap is covered with a thick wodge of flux. A very short
snippet of silver solder wire is embedded within this flux - only
enough solder volume to slightly overfill the 0.005" nominal
gap

With the blade horizontal (flux + solder on top) the UNDERSIDE
is heated with a propane or MAPP gas torch. This gives complete
visual control of the heating process without danger of under or
overheating. As the temperature rises the flux, while still
covering the solder, melts and becomes transparent. You can then
observe the exact moment when the solder melts and flashes into
the joint.

This consistently produces clean reliable joints which require
little or no dressing after brazing.

Jim