Jack, Hardwoods such as cherry, maple, and walnut should not be anymore dulling than poplar, bass, or pine. What wrecks h3ll out of chopper blades is compo, and the silica inheirent in raman and some of the "grass" woods.
What is valuable to know about what you are chopping is the percentage of hardwood & compo vs. softwoods. This can determine the most advantagous style of sharpening.
If you are chopping a marked percentage of softwood, you will benefit from a Hollow grind such as Tech Mark performs. But if you do more compo and hardwood, the fine edge of a hollowground won't stand up to the brutal blunt force trama of the chopping and will dull quickly. This is the purpose of Flat grind; to give more shock absorbing bulk directly behind the edge to radiate the shock. It also travels through the hardwood better, much the same as the difference of the duller Hardwood v-nails and the sharper grain slicing Softwood or Standard v-nails.
Also a factoid to knote, with each sharpening, a micro annealing occures, even with the cooling flood of grinding milk. Over time, this annealing takes its toll and the time between sharpenings become less and less. [this is in "Tool" steel] This has been observed for generations in the tool and machining industry and explains why you rarely ever see a short drill bit in a machine shop. About a 1/2" of grind down due to sharpening and they are amertized to zero and replaced.
We are looking at a new set of blades that are a composite, with the 1/8" of edge plate is made from A-4 with a Rockwell aquivilant of 64, bonded to a bed of ductal steel for body and shock absorbsion. They [grinders] think it will come in a few dollars less then the Tech Mark blades, but should triple or quadruple the effective cutting time between sharpenings. The advantage to A-4 is that it actually work hardens from sharpening instead of annealing.
I have A-4 blades for my wood turning, and rarely ever sharpen them... I'm really looking forward to seeing these new blades for the chopper.
Wow, talk about sticking a super charger on your dads studebaker!
