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ROUTINE MAINTENANCE
GRINDING STANDARD COUNTER KNIFE
When grinding the counter knives, extreme care must be taken to ensure that excessive heat isn’t put into the knife edge.
Excessive heat (indicated by discoloration of the knife edge) will lead to microscopic cracks that can cause the knife to break
when it is put back into service. DO NOT attempt to use knives that have been exposed to excessive heat from sharpening!
Once the discoloration appears, the knife can not be made serviceable again by simply removing the discoloration.
There are three sharpening methods that will provide a good cutting edge while reducing the possibility of excessive heat
buildup in the knife edge.
• Hand le
• Power belt sander with ne paper
• Conventional knife grinder with coolant system
The time between knife sharpening will vary with the type of wood and operating conditions. Sharp knives are essential to
good chip quality and nothing is gained by running the chipper with dull knives. Indications of dull knives are poor chips,
excessive oversize, nes, and poor feed characteristics of chipper.
The most suitable angle for any particular condition can only be determined by the trial and error method right on the job.
To achieve longer knife life, follow these steps.
1� Begin with a knife sharpened to 35°
45°
2� Use a honing stone to remove any burr edges left from grinding.
3� Listed below are several recommendations which are important for a quality knife grinding operation:
4� Whenever possible use a grinding machine that will repeat the desired angle and grind true and straight, avoiding the
straight wheel grinding.
NOTE: Straight wheel grinding will give a hollow or concave effect. This shortens the life of the knife and produces poor
chips.
5� We recommend a non-petroleum base coolant such as De Santo (orange label) grinding coolant, mixed approximately
one part coolant to 50 parts of water. The coolant should be applied on the wheel about 1” above the knife with full
pressure. This will keep the wheel clear and free to cut without burning or damaging knives.
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