Bandsaw Blade Resharpening

[onocoffee]

Do any of you have your bandsaw blades resharpened? I have a 112" Laguna Resaw King blade that I'd like to have resharpened, however, Laguna won't accept a blade over three years old and my local blade resharpener does not do bandsaw blades. So looking for a place that will resharpen the bandsaw blade anywhere in America. Thanks!

 

[PaulMarcel]

Not an answer for you, but I liked the idea of a Resaw King being easily resharpened. I sent one in and they called me to say it had been sharpened too many times. It was the first resharpening. I mentioned that and "oh, okay!" they sharpen it. It smelled slimy. It happened on the other blade as well.

I've wanted to make a jig to sharpen one with a diamond stone. Not as good as a real sharpening on their equipment, but if it is really close, I can avoid their BS.

Following for a recommendation though!

 

[Mini Me]

Look on YouTube on how to do it yourself. IIRC Derek Cohen does it and the information is most probably on his website.

 

[Packard]

The tool room in the company where I used to work, burned through a steady diet of band saw blades. They bought blades in large coils and used the band saw’s built-in cutter, welder and grinder to make a new one from those coils of saw blades.

I once asked the tool room manager why they did not have the blades resharpened and he laughed and said, “Band saw blades are consumables like hack saw blades.”

That is probably why you are having a hard time locating a shop that will resharpen the band saw blades.

How many years did the original blade last? How much is a new blade?

Addendum: I just looked it up. The “huge coils” I referenced above were 100 feet long. The premium blades (Starrett) were $2.43 to $2.88 per foot. So not for a small user (plus, you need a cutter, welder and grinder dedicated for this application).

But there are shops that will make up custom band saw blades. Get a price for a Starrett blade made to size in the tooth count you need. Lots of places to choose from:

Google Search

 

[P_K]

Steel bandsaw blades are fine but I wouldn't dry grind a carbide tipped anything in the shop as the alloy contains cadmium, cobalt and chromium. You definitely don't want any of that in your lungs.

 

[Cheese]

How much is a new blade?

Addendum: I just looked it up. The “huge coils” I referenced above were 100 feet long. The premium blades (Starrett) were $2.43 to $2.88 per foot. So not for a small user (plus, you need a cutter, welder and grinder dedicated for this application).

But there are shops that will make up custom band saw blades. Get a price for a Starrett blade made to size in the tooth count you need. Lots of places to choose from:

Google Search

Packard, the blade onocoffee wants to have sharpened is a carbide toothed bandsaw blade that probably costs around $150-$200 depending upon the size.

 

[Packard]

Packard, the blade onocoffee wants to have sharpened is a carbide toothed bandsaw blade that probably costs around $150-$200 depending upon the size.

A new Laguna carbide blade is $192.00 to $249.00 at Woodcraft, so I can understand the thinking behind sharpening.

My guess is that the probable reason for the 3 year limitation is that over time the band saw blades (the steel part) will fatigue and fail.

A good example of metal fatigue is when you take a wire coat hanger and bend it back and forth several times and it cracks. Harder grades of steel are more susceptible to to metal fatigue, but high carbon steel is less susceptible. Band saw blades are made from spring steel and will be less susceptible to fatigue except at the weld where it will be particularly vulnerable to cracking.

I doubt that Laguna is being capricious about the 3 year rule. They probably found that there was an unacceptably high failure rate on the older blades that lead to customer dissatisfaction.

Perhaps, if you write to them and tell them that after sharpening you will hold them faultless if the blade fails. I’m not sure it is a good idea, but they might allow sharpening if they are pre-immunized against any complaints.

There may also be brazing failures on older blades (the carbide is brazed to the steel).

In any case, from a business point of view, concerns about customer dissatisfaction may be driving Laguna’s sharpening policy.

 

[onocoffee]

Speaking of bandsaw blades...

This is the blade from the main mill at Hearne Hardwoods in SE Pennsylvania. Evidently, it was manufactured in the 1910s and was used at the Philadelphia Naval Shipyard until they got it sometime in the early 2000s. I forgot the length but they have ten of these blades. Five they typically keep at the mill and the other five are usually at the sharpener. From what they told me, the company that sharpens them will hold the blades for them.

 

[Packard]

One of the key advantages of large bandsaws is that the length of the blade prevents the blade from getting too hot and thus damaging the teeth.

Our tool room further controlled the heat by a continuous flushing of the cut with water-soluble cutting oil. The water soluble oil works better than the straight oil because the water is able to evaporate and further cool the blade. Of course, that is not reasonable for woodworking, but is essential for cutting large blocks of tool steel (in the “soft” condition prior to heat treating).

In any case, if you are doing resawing where the blade is likely to get very hot, you are best served with a saw which takes a long blade. That would exclude almost all bench-top saws. But even full-sized floor models vary in blade length, ranging from about 53” to 261”.

I do recall seeing a display of bandsaws at Sears. One of the lower priced “Full size” band saws, was just a benchtop saw mounted on a steel base. From a functioning point of view, no difference between it and the benchtop sibling.

Here is a list: https://www.bandsawbladecenter.com/BLADES_TO_SIZE.html

 

[P_K]

Hearne used to be a Festool retailer. One stop wallet emptying!

 

[PaulMarcel]

Mini Me mentioned that @derekcohen likely had a bandsaw blade sharpening jig. I do seem to remember that, too. So this reply is a bat-signal to see if Derek has some fine words about this.

 

[Mini Me]

Some Carbide blades can't be re-sharpened due to the size of the Carbide tip being too small. I use the Lennox Tri-Master and it is one of those that can't be re-sharpened but I don't mind. I have just replaced one that lasted 7 years and had cut god knows how much Australian hardwood in that time. Laguna had quite a few QC problems in the early days and that was the reason I went to the Lennox blade.

 

[onocoffee]

Hearne used to be a Festool retailer. One stop wallet emptying!

They got a lot of Festool in there, but I don't think they actively sell Festool now. Their Sysport setup was pretty cool though.

 

[derekcohen]

Mini Me mentioned that @derekcohen likely had a bandsaw blade sharpening jig. I do seem to remember that, too. So this reply is a bat-signal to see if Derek has some fine words about this.

Hi Paul

The article is here: https://www.inthewoodshop.com/Powered Tools and Machinery/SharpeningBandsawBlades.html

Copy-and-paste from my website:


I was asked to explain how I go about sharpening my bandsaw blades, and finally got around to putting together a couple of photos.


Let me say first that I did not invent this method. It is widely used. I learned it on YouTube, that font of all important wisdom

The fixture is new, and really thrown together in about 20 minutes. Before this, for a number of years, I would simply freehand this process. That worked well. Eventually .. recently .. I decided a fixture would offer more reliable results and less hand fatigue. Well, I think that this is so.


The main tool is a Dremel with a small diamond disk (the disks are available for pennies on eBay).


The blade here is bimetal 3 tpi 10mm wide. These are easy to sharpen. I use these blades for most everything except re-sawing wide boards.


I have also very successfully sharpened a 1.3 tpi 1" Lenox Woodmaster CT, which is a carbide tipped resaw blade.


The set up ...

This is made of two pieces of ply, at 90 degrees, the Dremel is wedged between the brackets at the desired angle, and held on with velcro straps ..

The method ...


Simply "touch" the back of the tooth and grind a teensy weensy flat. Damn these technical terms - not too complex I hope? The angle I choose is in line with the back, but it is not critical. What I believe that the fixture does (better than freehanding) is keep the height of the teeth the same. That ensures that all teeth are cutting.




Step 1. Mark the start of the blade (blue tape).


Step 2. Set the fixture against the bandsaw fence to keep it tracking square.


Step 3. Gently touch the wheel to the back of the tooth. Gently – enough to leave a silver flat.


Below you can see (not too well, I'm afraid - the shiny spot looks the length of the tooth, which it is not) a tiny silver shine on the back of the teeth sharpened, and the absence of this on those unsharpened ... a better picture would resemble the sharpening of a backsaw ..

The result ...


The wood here is hard, dry Jarrah. The two sides are the result of cutting with a freshly sharpened blade.

Additional notes



Regarding matters such as indexing and sharpening the face vs back ...

I do not index - this method is as basic as it can be without doing it freehand. It is better than freehand, as the angle is consistent.

How long can it be done? I have used the freehand method for several years, and sharpened the 10mm bimetal blades about 5 times. Then I toss them. I would say that I have had my monies worth. The cut can get slightly smoother each time since there is fractionally less set with each sharpening.

What limits how long you can re-sharpen is, firstly, the size of the gullet - too small and it cannot carry away sawdust, and then it loads up and affects tracking. The second factor is the stiffness of the blade. Carbide blades are stiffer as they are thicker. They eventually fracture, and this is more common among bandsaws with smaller wheels, such as 14” (more bending). My Hammer has a roughly 18” wheel, and my last 1” Lenox Woodmaster CT, a carbide re-saw blade, disintegrated. It had been sharpened about 5 times.

Back vs front? Not much difference - both leave the bevel edge sharp by removing the wear bevel.

Here is a method (by Terry Gordon, from HNT Gordon tools) for sharpening the front. A guide is important as there is some risk that one may alter the cutting angle by sharpening the front if you do this freehand ...



The number of teeth come into the equation. Too many and it will take hours. The 10mm 3tpi bimetal blades take about 20-30 minutes. The 1.3 tpi 1” blades take about 10-15 minutes.

I leave the blade on the bandsaw - some like to do this task freehand on a bench grinder, and remove the blade to do so. Leaving the blade on the bandsaw makes it easier to keep the angle consistent ... and yet the bench grinder method still works well, which says that the sharpening is quite accomodating to angles. I do release some of the tension from the bandsaw, and work with the blade moving down. This is less tiring.


Regards from Perth


Derek



November 2020

 

[onocoffee]

Thanks Derek. This is Epic.

 

[PaulMarcel]

Yes, thanks, Derek! On the never-ending list of things for the shop for sure.