Resharpening Bandsaw Blades

Arguments for and against sharpening your own bandmill blades versus sending them out to a resharp service. May 11, 2005

I am seeking information on bandmill sharpening equipment. I have been running a portable bandmill operation for the past four years recycling urban timber in the Philadelphia/New Jersey metropolitan areas. I understand that not all bandsaw blades are resharpenable. However, after my blades are dull, I send them out for resharpening. When they return, four out of every dozen will generally not cut true - they either climb or dive in the log. The cost of sharpening and shipping exceeds 50% of the cost of a new blade. I have used at least three different vendors with no difference in results. A number of years ago, after having similar bad professional sharpening experiences with chainsaw loops, I acquired a chain grinder and read the owner's manual and have never had a problem with dull chain loops since. What do you recommend for me to use to resharpen/reset bandsaw blades? I handle about 40-60 logs per week.

Forum Responses
(Sawing and Drying Forum)
I use a Cook's Cat Claw sharpener and am pretty satisfied with it. I sharpen about 25-30 blades a week, and can bring back some pretty damaged blades by sending them through several times.

I use the Wood-Mizer resharp service and have never had a problem. I also have a Wood-Mizer sharpener and setter that came with my mill but I like the looks of the Cook's sharpener more. Seems to be heavier/better built, but the Wood-Mizer does do the job.

I have never seen a Wood-Mizer sharpener close up or in operation, but I like the idea of the water coolant. If not monitored closely, the Cooks can burn blade tips. Does the WM coolant stream prevent blueing?

Try the sharpener sold by Timberking. It does a great job for me. No matter how sharp you get a blade, if the set is not proper, it won't cut straight and true.

Somewhere along the way, your blades need to have the tooth set to the correct saw kerf. If the teeth are sharp but the set is incorrect, the saw will not cut a straight line. The set is dependant on the size and type wood you are sawing.

I too use the Wood-Mizer resharp service. My blades are returned set and sharpened; I never have a bad blade. For me it is much better and more efficient than when I had to sharpen and set my own.

I've had some trouble with my bandmill like you are describing. There is an incredible difference in blades, kerf and material being sawn. All three of these will give different results. They can sell you an average blade, but it won't give great performance in pine as well as oak. Pine requires 15 degree hook and bigger gullets because the chips expand so much more than hardwood chips, causing heat that dulls blades.

One big thing I faced was the setup on the blade guides. I would double check everything from the manufacturer's specs. They usually require some down pressure with the guide rollers, and proper gapping if you have ceramic disks underneath. Back up bearings need to be properly spaced. Only once you check that the mill is exact, look at the blades you're getting back and measure the set. Was the whole tooth ground? Fronts, backs, gullet? Was it set properly within .001 on each side? Is it sharp? Is it the right blade for the material? Pitch, kerf and hook degree? All these things go into making a proper cut. You need to be a detective. Resharp programs don't make sense to me. With shipping they all cost $10 a blade, and they won't sharpen blades that are perfectly useable because they may be missing a tooth or two. This is easy to make up for with a used grinder. Just look at sawmill exchange and see if one of the mills listed with a grinder will sell it separately. You should save 50%. I just got an old Wood-Mizer and it works pretty good. I had to tune it up, and UPS dropped it off a three story building in shipping it, so I had to buy a bunch of new parts, but hey, life's full of adventure!

I sharpen for several customers and I find that on some bands the tips will burn more than on others. I also use a Cook's sharpener. I purchased a roller from Tim Cook and for bands that dive, we roll the band out flat. After it runs around the wheels and is tightened for several sharpenings, it develops a bow from the gullet down and if you don't roll them back flat, they will dive.

Some sawyers don't have enough knowledge about their machine to know when they have a problem with their sawmill. They send the bands out to be sharpened and then don't want to pay for them because they won't cut. Rollers that are worn out, too much pressure on the bands - many things can cause the blade to do different things. When you have sent your bands to several folks and they still don't cut, you better look at your own problems.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:
I had the same debate as well. Since the sharpening equipment that came with my first mill was in sad shape (disassemble and rusty in a box) I opted to take my blades to a local saw sharpener. The results were not good - burnt tips, no set to the teeth, and the saws would not cut straight. I ordered more blades and the parts to get the Wood-mizer sharpener working.

After doing some research into saw sharpening I was able to get 10-12 sharpening per blade with good results. I also found that my mill was not properly tuned and after spending some time tuning it up the quality of the cuts improved as well. I do not run my blades hard either. At the first sign that they are not cutting their best I pull them off and write a note as to how they were performing so that when I sharpen them I can solve any problems. If a tooth is missing set it to 0 and take the next tooth that is at 0 and set it to replace the damaged tooth. I like the water cooling option of the Wood-mizer sharpener, but I would get the dual tooth setter from Cook as setting the teeth is a time consuming part of saw sharpening, The band roller that is made by Cook is a must have as it saves wrecked and old blades from the scrap pile on a regular basis.

I talked with the local sawyer and found to my surprise that I am the only one in my area that sharpens my own blades. Others replace their blades after 1-2 sharpenings due to saw breakage. It seems that they have found that if they run their blades hard then send them off to be sharpened they are not getting the life out of the blade that they could. We have compared production for the life of the blade and by not running the blade hard I am getting more then twice the board footage per blade. I like to track each blade and can tell which one will last the longest by its history.

I have welded cracks and then ground them flush, and the key to doing this is to catch it early and center punch the end of the crack to keep it from spreading. Then roll the band to take out any twist the heat may have put in the band. Sharpening my own saws lets me try new things like swedging the tips rather then setting them. I am having good results with this on the double cut bands for the select mill, and on the Wood-mizer LT-70 I have changed over to running steel wheels with great results. Now I am trying out the 2" saws. However that still needs work. I run a mix of saws depending on what I am cutting. I maintain 75-100 saws because we cut all species of wood.

Comment from contributor B:
Our facility has two bandsaws, one for squaring the log and the other is a resaw. I spend a lot of time in our filing room working on blades. Benching of the saw is very important as bandsaws have what is called tire line where the blade grips the wheel. If they don't have the right amount of tension or the back of the blades is not longer you can have the sharpest blade and it will still run in and out! Make sure you have someone bench, tension and have the proper amount of back in the blade or it will never saw correctly!