Bandsaw silver soldering fixture

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Apr 5, 2018, 02:18 PM
thehomeengineer

3 Attachment(s)

Bandsaw silver soldering fixture

Hi All

I was able to purchase two coils of bandsaw blade from a local scrapyard for my Startrite bandsaw at a great price (£10 each coil). My bandsaw is fitted with a blade welder but for some reason I have never been able to get it to work well. So, I have always silver solder the blades together which works really well.

As a treat to myself:bananadance:.

I knocked up a new soldering fixture to aid the alignment of the two ends. Once the blade is cut to length I grind the two ends at approximately 45 degrees to increase the surface area of the joint rather than just butt the ends together. I have used this technique for years and have never had one break yet. The photos below show the fixture. Two M6 penny washers are bent to clamp/hold blade in place

Attachment 23040
Fixture with welded bar to enable it to be held in the vice so the heat source can be placed beneath the blade.

Attachment 23041
Ready for silver solder NOTE the splice to increase the mating face surface area and bent M6 clamp washers.

Attachment 23042
Silver soldered together. Another advantage for silver soldering the blade doesn’t require annealing

Thank you for viewing
The Home Engineer
Apr 5, 2018, 04:22 PM
mrehmus

Nice job,

I was taught to flip one of the blade ends over and then grind the ends at the same time. That way the resulting joint will be straight. Of course we were using a blade welder, not a brazed joint. The annealing process was to first hold the lever on the welder down until the weld was made and then pulse it in decreasing amounts to anneal the weld. Never had one break.
Too bad the stand-alone welders are in the $600 and up prices here in the U.S.

Fortunately, a good braze job is stronger than the metal being joined.
Apr 6, 2018, 01:52 AM
thehomeengineer

Quote:

Originally Posted by mrehmus

Nice job,

I was taught to flip one of the blade ends over and then grind the ends at the same time.

Hi mrehmus
Every day is a school day. That is a great tip which I was unaware of thank you for the reply and I will be trying this tip next time I make a blade.
The Home Engineer
Apr 6, 2018, 03:04 AM
pfredX1

When I brazed bandsaw blades I double scarfed the joint. Someplace I have a picture of the jig I made. It is similar to what's here. http://i.imgur.com/7SrdP.jpg

Yeah I was certainly in the mood to mill that day.
Apr 6, 2018, 07:07 AM
Ralphxyz

I thought the jig should be made from wood so that the heat is not dissipated quickly.

I like to see the actual brazing.

Ralph
Apr 6, 2018, 10:42 AM
thehomeengineer

Quote:

Originally Posted by Ralphxyz

I thought the jig should be made from wood so that the heat is not dissipated quickly.

I like to see the actual brazing.

Ralph

Hi Ralph
I will do a video on silver soldering very soon and post. The temperature of the silver solder I use melts at 720-degree C so very hot and the wood could cause a fire. I hope this has answered your question and thank you for taking the time to view the post.
The Home Engineer
Apr 6, 2018, 10:50 AM
thehomeengineer

Quote:

Originally Posted by pfredX1

When I brazed bandsaw blades I double scarfed the joint. Someplace I have a picture of the jig I made. It is similar to what's here. http://i.imgur.com/7SrdP.jpg

Yeah I was certainly in the mood to mill that day.

Hi pfredX1
I would be very interested to see the joint if you are able to find the photo. Anything to make improvements to what I do is very welcome. Thank you for taking the time to view and reply to my post.
Apr 7, 2018, 07:06 AM
DIYer


Thanks thehomeengineer! We've added your Bandsaw Blade Soldering Fixture to our Bandsaws category,
as well as to your builder page: thehomeengineer's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-bandsaw-blade-soldering-fixture"> <img src="/uploads/212492/homemade-bandsaw-blade-soldering-fixture.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-bandsaw-blade-soldering-fixture">Bandsaw Blade Soldering Fixture</a> <span> by <a href="http://www.homemadetools.net/builder/thehomeengineer">thehomeengineer</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/bandsaw'>bandsaw</a>, <a href='http://www.homemadetools.net/tag/soldering'>soldering</a>, <a href='http://www.homemadetools.net/tag/fixture'>fixture</a> </div> </div> </div> </div>
Apr 18, 2018, 06:24 PM
wizard69

Quote:

Originally Posted by thehomeengineer

Hi Ralph
I will do a video on silver soldering very soon and post. The temperature of the silver solder I use melts at 720-degree C so very hot and the wood could cause a fire. I hope this has answered your question and thank you for taking the time to view the post.
The Home Engineer

That would be most welcomed, a picture is worth a 1000 a movie millions.

This appears to be a simple fixture to make, so all I really need is likely some silver solder. I must ask though do you believe a propane torch could heat the band fast enough to do a silver solder joint properly? Also preferences for solder and flux would be appreciated.
Apr 18, 2018, 06:40 PM
mrehmus

Propane is probably not hot enough and you need to be careful that you don't take the temper out of a large section of the blade with a large flame. MAPP gas would probably work using on of those small torches with the small flame.
Apr 19, 2018, 01:37 AM
thehomeengineer

Hi
Propane is fine to use for silver soldering. I use a Sievert torch for silver soldering and the size of nozzle can be changed to suit the application being under taken. However, Mapp gas is the way I solder the blades purely for convenience, as it is a hand held torch with no hoses.
I will try to do the video this weekend and post.
There are several grades of silver solder and the main difference is silver content, which alters the temperature and price. I use what was, called easy flo, (which I think? is known as 455 now) which has a melting point of 630-660 degree C. This is classed as low temperature silver soldering and the flux I use is the high temperature HT5 Flux Powder. This means I only have to buy one flux, which covers all the materials I will be soldering in my shop.
Hope this helps
The Home Engineer
Sep 9, 2022, 01:18 AM
uv8452

Dear Home Engineer, I was forced too to switch from welding to silver soldering. (thanks to HMT...) Soldering requires more diligence but doesn't fail. The inclination of my grinding is about 2:1. My jig has more space for the flame: 40mm lengthwise and 40mm in the back of the blade. The upper part of the clamps is 12mm wide and 4mm thick - kind of a toolmakers clamp with 2 screws. The lenght of the guide for the back of the blade (left and right side each) is 80mm - the longer the easier to adjust the blades. That helps to get the back of the soldered blade straight. If not, noise and (the imagination of) dynamic stress disturbs you. I file the excess of solder and misalignment with an extra hard 'Corinox' file.