Published: June 5, 2016
Lawn Mower Blade Sharpening
Lawn mower blades are hard. They have to be because of the tremendous beating they take. Metal hardening is a critical issue with manufacturers because if the blade is too hard it become brittle and will crack or chip when it encounters a stone or practically any hard object in the grass. On the other hand, if the blade is too soft, it will dull easily and need regular sharpening which decreases the life of the blade.
When you take your blades off for sharpening, take a good look at them and try to determine what their inherent weakness may be. If they are bent or very dull you may want to try another brand of blade. If they are cracked or chipped, you may want to try antother brand also. Switch brands once in a while until you find one you are happy with. All blades are not equal.
Sharpening lawn mower blades is somewhat critical too. The very best way to prevent damage from the sharpening process is to place the blade in a steady, bench-mounted vise and use an aggressive file to resharpen the edge. It takes a long time and many of you may not have a vise. Be sure to wear heavy leather gloves while sharpening because just one slip and you can get a mighty nasty cut.
What about using power tools? Well, it makes sharpening a lot quicker but if you do not control the heat, you will soften the blade and it will then experience a short, short useful life. Here is a method that does work though – keep water running on the blade and don’t sharpen but a few seconds at a time. Even with the down time for cooling, it is much quicker than sharpening with a file.
Here are photos of a pair of blades I sharpened with a power grinder with a “flapper” sanding disk attached. The blades were fastened securely in an outsed vise and water from a water hose ran over them constantly. I checked every 20 seconds or so for heat. If the blades get too hot to touch, you’ve already gone to long. Alternate between 5 seconds of sharpening and 10 seconds of cooling. Take your time and you can get lawn mower blades sharp like these:
Published: May 31, 2016
Mercer 8″ Chef Knife Sharpening Service
Super Sharp Shop – 251-583-5955
Mercer knives are a good value and I enjoy working on them. They can be challenging at times, especially when they see heavy use and inadequate care. This was the case when a local chef brought in her Mercer 8″ chef knife for reconditioning and sharpening.
This particular knife had quite a bit of damage and I am not sure I can figure out what caused the damage but the chef did say the knife had been sharpened on some type of wall mounted sharpening device. If I had to take a guess, from the looks of the knife edge, I would say the knife was probably pushed into the sharpening mechanism too strongly and twisted as it was removed. There were large gaps of the cutting edge broken off and three bends in the edge elsewhere.
Here is a photo of the knife edge under magnification.
As you can see, it is pretty rough. My challenge was to not only sharpen the blade but to restore a working edge with bends in addition to the large chips. Actually, the damage was much more than chips — some of the missing cutting edges were up to an inch long!
Nothing to do here but start over with profiling the edge. I started with a 42 degree bevel for the edge foundation and worked the edge with first 220 grit and progressing to 1000 grit. The 42 degree edge was quite sharp after about an hour of re-profiling and polishing but Mercer Chef Knives are designed for a 22 degree cutting edge. So, next a 22 degree edge was built on top of the 42 degree edge. This guarantees a strong edge that should not damage as easily as having a 22 degree edge only. Starting with a few minutes on 400 grit, I progressively worked thru 600 grit and 1000 grit. Then I sat down in front of my TV and spent about 30 mintues polishing the edge with 2000 polishing tape and finally 3000 polishing tape. The knife turned out beautifully and I am going to recommend to the chef to stay away from that wall mounted sharpener, whatever it is, and use only a ceramic rod to keep the knife sharp.
Have you got a problem knife? I cannot guarantee success on every knife but I do enjoy a challenge. Call Terry at two-five-one | five-eight-three | 5955.
Published: April 15, 2016