#15264

I now have 2 broken blades. I have no idea what happened to the first, and I can't really remember what I was doing when it broke. The second broke as a result of my own stupidity. (Note to newbies - if you ever disconnect the counter balance spring, make sure you reconnect it before you use the saw again!)

My question - what can I do with the old blades?

My hottest flame is a Bernzo-matic plumbers torch, and my hottest electrical source is an old Weller soldiering gun, so repairing them myself is probably out of the question.
Is it worth it to have them repaired? A new blade is only $20 or so, but I have not priced repair. (I don't know anyone who could do it as a favor, so I would have to pay a shop to get it done.)

I have several old hacksaw blades as a source of spring steel for clips etc.

I am looking at 3 cents a pound recycling, but I thought I would ask before I did that.

Thanks

Karl

#15265

开云体育

Well blade repair is a brazing operation so I would expect the Torch to work fine scarf the ends evenly about ? to ?”, and then braze/silver solder them. Then grind it back totally flat.

The last time I broke a blade was like 17 years ago, I bought two new blades then and while waiting to get them did the silver braze on the broken one, figuring it wouldn’t last. [It wasn’t that good looking a braze job either. I vaguely recall it took me three tries]

I am still waiting for it to fail or get dull (I don’t use it all that much, perhaps once a month or so), meanwhile I have lost track of one of the replacements, and the plastic bubble on cardboard for the other has completely disintegrated.

?

It was using a jig much like (but aluminum) much like what is shown in the graphic on this

?

or this

?

Now that jig is considerably more expensive than buying 1 replacement blade is, so do your own math……

Sometimes it is worth it just for the experience.

?

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#15266

You can braze them.?

His spelling is a little wobbly, but the photos show much of what you need to know.?

HTH

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)

A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)

On Wednesday, June 24, 2020, 01:15:15 PM CDT, <edfredfred1@...> wrote:

I now have 2 broken blades. I have no idea what happened to the first, and I can't really remember what I was doing when it broke. The second broke as a result of my own stupidity. (Note to newbies - if you ever disconnect the counter balance spring, make sure you reconnect it before you use the saw again!)

My question - what can I do with the old blades?

My hottest flame is a Bernzo-matic plumbers torch, and my hottest electrical source is an old Weller soldiering gun, so repairing them myself is probably out of the question.
Is it worth it to have them repaired? A new blade is only $20 or so, but I have not priced repair. (I don't know anyone who could do it as a favor, so I would have to pay a shop to get it done.)

I have several old hacksaw blades as a source of spring steel for clips etc.

I am looking at 3 cents a pound recycling, but I thought I would ask before I did that.

Thanks

Karl

#15267

Karl:

You can make a sheet metal hole saw, like shown in this .? Pretty clever.

Other Bill

On Wednesday, June 24, 2020, 11:15:14 AM PDT, <edfredfred1@...> wrote:

I now have 2 broken blades. I have no idea what happened to the first, and I can't really remember what I was doing when it broke. The second broke as a result of my own stupidity. (Note to newbies - if you ever disconnect the counter balance spring, make sure you reconnect it before you use the saw again!)

My question - what can I do with the old blades?

My hottest flame is a Bernzo-matic plumbers torch, and my hottest electrical source is an old Weller soldiering gun, so repairing them myself is probably out of the question.
Is it worth it to have them repaired? A new blade is only $20 or so, but I have not priced repair. (I don't know anyone who could do it as a favor, so I would have to pay a shop to get it done.)

I have several old hacksaw blades as a source of spring steel for clips etc.

I am looking at 3 cents a pound recycling, but I thought I would ask before I did that.

Thanks

Karl

#15268

Thanks, all.

My only previous attempt at silver soldering was with considerably larger pieces and it didn't go well, so I figured I needed a different heat source.

The videos and articles make it look pretty easy, so I will give it a whirl.

Thanks again. I'll post an update in a few days.

Karl

#15269

Another link to add to your toolbox:??

HTH!

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)

A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)

On Wednesday, June 24, 2020, 05:56:57 PM CDT, <edfredfred1@...> wrote:

Thanks, all.

My only previous attempt at silver soldering was with considerably larger pieces and it didn't go well, so I figured I needed a different heat source.

The videos and articles make it look pretty easy, so I will give it a whirl.

Thanks again. I'll post an update in a few days.

Karl

Ralph Hulslander

#15270

Karl, where are you? I have a friend with a bandsaw welder.

Ralph

Show quoted text

On Wed, Jun 24, 2020 at 8:42 PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:

Another link to add to your toolbox:??

HTH!

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)

A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)

On Wednesday, June 24, 2020, 05:56:57 PM CDT, <edfredfred1@...> wrote:

Thanks, all.

My only previous attempt at silver soldering was with considerably larger pieces and it didn't go well, so I figured I needed a different heat source.

The videos and articles make it look pretty easy, so I will give it a whirl.

Thanks again. I'll post an update in a few days.

Karl

#15271

开云体育

“The videos and articles make it look pretty easy, so I will give it a whirl. “

?

Well they do not show you the times they tried, and it didn’t work J

?

I think it is almost all about the prep.

You want the joint area clean and flat with the joint to have no real gaps.

Make sure you flux it well and have the solder ready to go.

And don’t give up if it doesn’t work the first time.

Avoid breathing the fumes and keep the flux off your skin.

The good fluxes contain fluorides nasty stuff, but they make the brazing easy peasy.

When the “solder” melts it should suck itself right into the joint.

?

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#15272

Prep and cleaning. Those are the keys to the Kingdom. ;) If you clean it well, flux it well, heat it well, and hold it firmly in place while doing so you WILL get a good joint. Brazing is easy once you know how. Though it does help to have good equipment, too. And practice!

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)

A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)

On Thursday, June 25, 2020, 10:18:45 AM CDT, Jim.Klessig@... <jim.klessig@...> wrote:

“The videos and articles make it look pretty easy, so I will give it a whirl. “

?

Well they do not show you the times they tried, and it didn’t work J

?

I think it is almost all about the prep.

You want the joint area clean and flat with the joint to have no real gaps.

Make sure you flux it well and have the solder ready to go.

And don’t give up if it doesn’t work the first time.

Avoid breathing the fumes and keep the flux off your skin.

The good fluxes contain fluorides nasty stuff, but they make the brazing easy peasy.

When the “solder” melts it should suck itself right into the joint.

?

OUR EMAIL ADDRESSES HAVE CHANGED

We were xxxxx@vertivCO.com and we are now xxxxx@...

?

?

CONFIDENTIALITY NOTICE: This e-mail and any files transmitted with it are intended solely for the use of the individual or entity to whom they are addressed and may contain confidential and privileged information protected by law. If you received this e-mail in error, any review, use, dissemination, distribution, or copying of the e-mail is strictly prohibited. Please notify the sender immediately by return e-mail and delete all copies from your system.

#15273

开云体育

I am fortunate to have a DoAll Blade Welder that can weld 1" blades. The process is called Flash Butt Welding. In the shops of the company I work for we also have "blade welders" that can weld railroad rails together. These can weld 155#/yd rail (8" tall x 6-3/4" base) in about 90 seconds. These welders can weld 80' rails into 1460' strings which are loaded on rail trains and delivered to the installation site. Power service to these machines is 460VAC at 800 Amps and they weigh about 75 Tons. Likely too large for most home shops.

?

But before the DoAll welder I had to braze or more correctly "Silver Solder" Blades. Just as in painting a car, the prep work is everything and if done correctly the soldering is the easy part. I found it best to not grind the scarf joint before soldering. I grind the "tooth set" from the faces of the blade to be joined and lap the to blade ends together for a distance of 1/2" to 1". The goal is to have a "no gap" joint. Don't get crazy here, if you lap too much the finished repaired blade may be to short to go over the saw wheels when you are done. Even in FBWing broken blades back together the results can be too short. If this is suspected to be the case I will weld too broken blades together and cut out a section to get the correct length needed to fit the saw. The left over material is saved for the next time length has to? be added, just be sure to have at least 10" or 12" between joints.

?

A dirty grinding wheel will cause soldering problems also. The wheel should be new or newly dressed to be sure that things like copper, brass,? aluminum,? stainless, etc. are not deposited on the surfaces to be joined by the dirty wheel. The faces to be joined should be liberally fluxed and a piece of Silver Solder "Foil" place between the lapped ends of the blade. Heat gently until the solder is seen to melt and suck into the join. Remove the heat and immediately press the sandwiched blade flat with a piece of preheated metal.

?

You now should have a lapped blade that has no chance of going thought he guides unless you run the saw real fast. To solve this, bend the now annealed blade at both ends of the lap until the main portion of the blade on both side of the lap is in a straight line. Now grind the protruding lapped end flush with the main body of the blade. Go slow so you don't over heat the ends of the lap and melt the solder loose while checking the thickness frequently. Ideally you would remove the same amount from both sides but there is a bit of leeway as long as the overall thickness is correct. Lightly grind the back also to level the joint.

?

I was never really successful until I adopted this method. It is just about impossible to freehand grind a tight scarf joint on the ends of the blade, especially without burning the ends. The success or failure of a soldered joint can be measured by the thickness of the solder interface.

?

So now I will go back into hiding like a "lurker on a porn site" until the next time.

?

gary

Show quoted text

From: [email protected] [mailto:[email protected]] On Behalf Of Jim.Klessig@...
Sent: Thursday, June 25, 2020 10:19 AM
To: [email protected]
Subject: Re: [4x6bandsaw] Old Blades

?

“The videos and articles make it look pretty easy, so I will give it a whirl. “

?

Well they do not show you the times they tried, and it didn’t work J

?

I think it is almost all about the prep.

You want the joint area clean and flat with the joint to have no real gaps.

Make sure you flux it well and have the solder ready to go.

And don’t give up if it doesn’t work the first time.

Avoid breathing the fumes and keep the flux off your skin.

The good fluxes contain fluorides nasty stuff, but they make the brazing easy peasy.

When the “solder” melts it should suck itself right into the joint.

?

OUR EMAIL ADDRESSES HAVE CHANGED

We were and we are now xxxxx@...

?

?

CONFIDENTIALITY NOTICE: This e-mail and any files transmitted with it are intended solely for the use of the individual or entity to whom they are addressed and may contain confidential and privileged information protected by law. If you received this e-mail in error, any review, use, dissemination, distribution, or copying of the e-mail is strictly prohibited. Please notify the sender immediately by return e-mail and delete all copies from your system.

#15274

I have refined my technique to silver-solder blades.? Since then, I have had zero break at the silver solder point.? Here are the highlights:

1.? Make a scarf joint by grinding each blade at a diagonal and shoot for a matching overlap of about 1/4 inch.? I made a wooden grinding fixture to help make the grind more uniform.

2.? Mount the blade in a fixture that will hold the two ends in alignment during the brazing. My fixture has a gap in the center for the brazing.

3.? Take a thin ribbon of silver solder (in my case I think that it is 55% silver but in a wire form, so I hammer it until it is about 1/4" wide and very thin - - perhaps 0.010") and cut it to the dimension of the width of my blade.??

4.? I then flux both pieces, overlap them, slip in the thin ribbon of silver solder and verify alignment.? If necessary I sometimes will put a very slight bend in the blade so that the scarf joint is held in compression.??

5.? Then I fire up the propane torch and heat the prepared joint until I see the silver solder melt and flow.? Remove the heat.? Then I file the blade until the joint is smooth on both sides and equal thickness.?

6.? Then I anneal the blade on each side of the joint.? Just enough so that it doesn't have a big transition point between soft and hard.

Others may have different techniques that work well for them.? But my technique works well for me.

#15275

Ralph, Thanks for offering your friends welder, but as of 2 days ago, I have working jigs for scarfing and brazing bandsaw blades!

My first attempt worked well, but the next blade had 2 failures before I got it to work.

I made the welding jig out of aluminum and I only had about a half inch gap in the jig. I think the jig was acting too much like a heat sink so I had to heat it quite a bit. After I widened the gap to a bit over an inch, I was able to use a smaller, more focused flame.

Thanks to everyone who contributed to this discussion.

Karl

Ralph Hulslander

#15276

I have seen jigs that were predominately wood to avoid the heat loss, apparently if you are careful?you do not burn the wood but even if you did burn the wood so what,? just make a new one from a new piece of wood you just reuse the metal parts.

Ralph

Show quoted text

On Sun, Jun 28, 2020 at 7:55 AM <edfredfred1@...> wrote:

Ralph, Thanks for offering your friends welder, but as of 2 days ago, I have working jigs for scarfing and brazing bandsaw blades!

My first attempt worked well, but the next blade had 2 failures before I got it to work.

I made the welding jig out of aluminum and I only had about a half inch gap in the jig. I think the jig was acting too much like a heat sink so I had to heat it quite a bit. After I widened the gap to a bit over an inch, I was able to use a smaller, more focused flame.

Thanks to everyone who contributed to this discussion.

Karl