Question
I have been debating on sending my Woodmizer saw blades to their re-sharp center. I live in Western Canada and wonder if the exchange on the dollar would make it feasible. I presently sharpen my own blades but find it time-consuming and feel that the company could do a better job than I can.
From contributor M:
Don't know about the exchange rate, but do firmly believe that you're gonna cut better and be very happy with the re-sharp service. You might just want to have a few more bands in your inventory to keep you in a sharp one while the others are being sharpened. I was not keeping track of where I was on blades and had a job lined up and no sharp blades to do it.
The most concerned employee a guy has is himself, so it stands to reason the he would do a better job if he knows how. The reason to send a blade out, I think, should start with the economics.
If you know how to sharpen and know how you would fix a blade, then you can be more critical of the "professional" service.
Cost of re-sharp:
$6 per blade, 8 blades per box and $8 per box shipping each way. Final cost for re-sharp service: $8/blade.
Cost to sharpen myself: $2000 for re-sharpener or an offset of 250 blades re-sharpened (not including labor). Compared to having, say, an extra 4 cases (minimum) of blades on hand to facilitate the 2-week turnaround on blades (costing $1000). So a thousand dollar over-investment on the sharpener... Not withstanding the resale value of the machine when I quit.
I can re-sharpen 4-8 blades per hour, so in comparison, to reshape prices that's a repayment in hourly wages of $32/hour to $64/hour. A savings comparable to charging equal money sawmilling... what did I say? Sawmill for an hour at $50/hour or spend an hour sharpening, thereby not spending 32-64 dollars for sharpening services, showing a net loss/gain of -18 to +14 dollars per hour...Head hurt yet?
If I pay someone $15 an hour to work for me and sharpen blades, I can recoup a minimum of $18 dollars per hour in savings.
Also, re-sharp ate my blades up. They were quite liberal in the amount of material they ground off the blade, ensuring a fully sharpened blade (can't blame them for that) and I feel that it reduced the amount of reuses that I could get. I grind the minimum amount off that will achieve fully sharpened teeth (or at least try to). I bone up a sharpening once in a while, but on average my sharpening is as good, with maybe the exception of loosing some hardness in the tooth from the heat of sharpening.
Setting is a bit tougher, to be as good as Woodmizer. But then again, you can set what you need or reset if you need more without the loss of the blade for the 2-week turnaround.
My quality of sharpening isn't always as good as the re-sharp program. But my blades won't vibrate tooth to tooth in transit through the not-quite padded shipping methods of UPS for 800 miles. What do they say, .001" of cutting edge? Not much of a bump to change that in transit.
And for those who "don't have the time to sharpen" because the only thing that pays is to "sawmill", I say that sharpening is part of sawmilling ever since the first saw. A dull saw isn't economic to run. And a sawmill runs on cash flow! You have to stop to change the oil, lube, clean, and sharpen; it's all part of the sawmill operation. For those who are one-man operators like me, there are rain days and other down times to budget in sharpening.
I can see that larger commercial mills, where they are moving more blades per day, may want to shift a cost of employee(s) to service expenses, changing a lot of tax issues for the money spent.
One last comment: I always wanted to get the most board feet out of a blade, knowing I was going to pay to have someone sharpen it (under the re-sharp program). This often resulted in slower sawing times and reduced performance. I now won't hesitate to switch a blade, because it's no longer an additional cost to change it. I'll get it sharpened in some down time later.
I do not use a de-barker, so I don't expect anything more of my blades.
As for welding the blades, it's a waste of time if a blade dies a normal life (not due to tramp metal, etc)--the entire blade is fatigued to near failure. Take a scrap blade and fold it by hand. If that blade snaps you've reached the fatigue life of the blade; if not you may have been over-sharpening the blade (running out of blade before fatigue). To weld it at that time will ensure failure at another location soon.
Properly sharpening the blade surface shaves off the microscopic cracks in the gullet, helping extend the life. Providing you are not sharpening too much blade off or grinding in such a way to overheat the blade.
No debarker here, either.
I have a Wright automatic (cam) sharpener, and a Dino semi-auto setter. I have no trouble at all setting the blades, but once in a while have trouble dressing my grindstones.
Sometimes a blade does not perform like I would like, but that happens with new ones, too.
I mark my blades at each sharpening, and have done some of them 6 times, but on the average probably 4 times.
I have tried having broken blades re-welded, with no good results at all. The best performance was about 5 minutes, and it cost me $5 to weld it. Now they go to the salvage yard.
I have noticed that running a blade longer than you should will shorten its life a lot. Heat, strain? If you're cutting big dry larch cants for vertical grain boards, you need to change frequently, whereas little pecker poles will saw without complaint even when a bit dull.
How long on average, in hours, do you run your blades? Do you keep track? I know that because of log size and type, there will be all kinds of different answers.
One reason NOT to keep using a dull blade is the small cracks that develop in the gullet of the blade. This is normal and as stated before they get ground out when sharpened, but if you run the blade too long, these cracks get bigger and the next sharpening doesn't get all the cracks out and you may have a broken blade.
About the time we went full time, the Woodmizer re-sharp program started. At that time, it was a godsend. Except for a rare blade, they did a good job. The only problem was, out here in Kansas, it was a pretty long turnaround time going back to the re-sharp center. It took lots of blades and lots of time and money packaging the blades.
When we did our expansion to a super HD40 Woodmizer, we decided to add sharpening equipment. We bought the sharpener and setter from Suffolk machinery, which I fully recommend. We started out with Woodmizer blades, but had a lot of blade breakage after 3 to 4 sharpenings. Might have been learning how to run the sharpener--maybe we were running the blades too hard or too long--I really don't know. Then we started using the Timberwolf blades from Suffolk machinery. We found we could get 10 or more sharpenings on most blades. The only problem was, after a while, the blade refused to cut straight, no matter how perfect the set or sharp the blade. Several months ago I tried Woodmizer blades again. This time we are getting about 5 sharpenings per blade. But the big difference is that they stay on the mill much longer, and don't wave in the cut near as much. The reason for the breakage at about 5 sharpenings is the cracks in the gullet, which makes me wonder if I'm not taking enough material on a grind, or else we are running them too long between sharpenings.
Our usage of Woodmizer blades is about 15 for a 45-day period. That's cutting 5 days a week. Pretty close to the usage of the Timberwolf blades. Probably after figuring downtime, etc., cutting about 28 hours a week.
When I cut red oak (wish I could cut it all the time), I have cut as long as 7 hours on a blade. I don't cut it often enough to have an average.
When cutting pine, I can get 3-4 hours per blade, but when cutting spruce, the knots will, without fail, let you know when to change your blade.
When I make the first pass through a spruce log, the blade better be right, or the results will look like a candidate for a roller coaster. Once I have a spruce log cleaned up on all 4 sides, it cuts pretty good and a blade will last as long as in pine.
Cutting ash, the blades last a bit longer than in burr oak.
Sometimes a blade will sucker me into leaving it on way too long, but if I notice any loss of performance, I switch blades immediately.
Most of the logs I cut are not particularly dirty either, but there is always some grit in the bark.
I use a 50/50 mixture of bar chain oil and diesel fuel and let it drip directly on the blade, and I have a plastic jug filled with the same stuff mounted by my operator station and spray the bottom of the blade every couple boards. It is one of those jugs that has about 18 inches of hose with the nozzle at the end.
I could probably cut more than a couple hours, but if I stretch it out too much, I may hit a hard knot somewhere in the log, and the blade starts to go off in a direction other than straight ahead. If I keep going when I see this, the blade sometimes veers off so far that it breaks. If I stop and try to back out of the log, I usually pull the blade off and a lot of times it kinks so bad I have to throw it away. For me, it is a lot easier to change blades oftener and touch them up on the grinder.
I do not cut for my living, but still enjoy cutting at a nice feed rate, which I can manage by changing blades as often as I do.
Although I would like to get a thousand sharpenings and unlimited time, I find that the best measure of a blade's endurance is the number of feet it can cut before failing or having to be removed.
The type of wood makes a difference and the thickness of the boards makes a difference, as does the size of the log, but if you use a little "Kentucky windage" in your mental eye, you can get a real good feel for blade life. You also generate a mental list of things that cause your blades to have shorter life.
I try to keep my sights set on the amount of wood I can saw in a working day. It's a pretty good goal.
I have a debarker on my lt40 WM and it is worth every penny. Re-sharp does a good job and keeping the blade cool makes it last longer. I run water and pine oil mix on my blade while I saw. Have not broken any blades before they get too narrow to sharpen. (Well, there was a mule shoe one time.) I do not think the grade lumber buyer would like diesel fuel all over the red oak. I would not know what a "down day" is, so to sharpen blades is out. I think that you guys need to get a water tank and a de-barker and start counting bd ft.
Board feet? Is that board feet of 1" stock, 4/4, 5/4, 6/4 etc and what kind of wood?
Time? Is that time in the cut? Is the saw running out of the cut on the return to cut? What feed rate and size of stock are you cutting?
Other generalities... Debarker or not? Size, ie. width of cut, tooth pitch? What about sawmill wheel diameter, blade thickness, and tension? All of that will effect the life of the blade.
Some people alluded to wavy cuts especially in knotty wood. I moved to a lennox 3/4 pitch blade for the hardwoods and knotty stock for that with good results.
I read somewhere about circle mills; the feed speed was relational to the number of teeth passing through the cut, so blade RPM was proportional to the feed of the setworks. Would that not be relational to the linear feet per min on a band mill and the number of teeth per inch?
That's without discussing toot angle and set....
It doesn't matter what you are sawing, a dull blade means less footage and footage is the goal in a production atmosphere.
Now don't get me wrong, I cut stuff for folks where speed and production is secondary but a good blade makes a better cut. Why use an old one that fights the wood?
If I were to cut 100 feet and change blades I could get a lot of sharpenings. If I ran a blade 4 hours, the last 30 minutes on some blades would be fine.
Comment from contributor I:
I sharpen my band blades myself. When I first got my mill, I learned that if you let them get just a little bit dull, you have wavy cuts, so I tried sharpening with a chainsaw file. Worked great sharpening just the face of the tooth, but took 4 to 5 hours, so I went to a 4 1/2 inch side grinder. Works great and takes about an hour or so. I find that if you put a c in the face of the tooth, the blade will carry a lot more sawdust instead of grinding it up and leaving it in the cut. The automatic sharpeners are also capable of grinding a c in the face of the tooth, like I can by hand.
