Posts: 25
Threads: 11
Joined: Jan 2018
Hello Forum.....Its been a while....
When Tormek brought out their new Diamond Wheels, I got the bug again to invest my spare time into Learning, Reading, Researching how to produce Sharp and Keen Edges.
I am still a beginner. Probably less than 200 knives/scissors under my belt. I can now comfortably take a dull knife, and make it less dull!
I want to do better. But more importantly, I want to quantify my results, so this week I hope to order my PT-50 ( A or B) ( But probably A).
I was also going to get a SJ-250...but after reading many posts here, for less money I can get a bench grinder and Paper Wheels, but feel I need to master the First Grind on my Tormek, before spending another cent ( beyond my PT50).
So here is my question:
What sort of sharpness does a skilled sharpener get right off the Tormek SG-250 and Leather wheel as supplied??? I guess I am looking for a target result to hopefully achieve in the near future...
Yes...I know it depends on the blade, so I am thinking just a commercial grade of stainless kitchen knife (RC 52-54?)
Thank you for your input in advance,
Sam
Posts: 504
Threads: 55
Joined: Feb 2017
Welcome, Sam.
Grepper's advice is very solid. Before he went over to the dark side of the force with his Kallie, he was one of the most innovative, stalwart Tormek users. We still love him, and pray continually that he will repent and return.
Enough good natured kidding. I have the orignal PT-50. I have been very satisfied with it. However, if I was starting from scratch, I would opt for the PT-50A. I have no doubt that the B would more than do everything I might need. I have a hobby interest in precision measurement. Sometimes the overkill hobbiest in me outweighs the thrifty, practical realist. I would rather drive a practical car, which will wear out, and have a top of the line tool, which will last longer than I do.
Back to the Tormek and the SG-250. For those of you who may not know, I believe "SG" refers to SuperGrind. (250 is the wheel diameter in millimeters.) The original Tormek grinding wheels were natural stone, mined from a Swedish island.
The SG stones are manmade aluminum oxide. They are faster cutting and more coarse than the original stones. I think the original use of the stone grader was to allow the SG stones to utilize their inherent faster cutting and also to be graded finer, like the natural stones.
Orthodox Tormek technique, 220 and 1000 grit from using the stone grader with the SG, ignores two other subtle controls. First, the stone grader can produce more than two grits. On a practical basis, there is also a middle grit, called “600”. This is essentially a medium grit somewhere between 220 and 1000. Related to this, I have found that using the stone grader fine side for longer than the recommended time produces a smoother finish.
The second factor is grinding pressure. At my request, Grepper, our USB microscope guru, made some edge photos showing the effect of using light grinding pressure with the final passes. I was impressed with the difference.
The third factor is using the leather honing wheel with the knife controlled by the jig and support bar. Most of us, myself included, are not really experienced enough with freehand honing to make it work well.
All of this is my sttempt to make the case that I believe very few Tormek users really get the maximum finesse with the SG-250. I use and like the new diamond wheels. They definitely cut faster. I am not convinced that they will produce sharper edges. They also transform a $600 sharpening machine into a $1500 machine. For that difference, my practical side is willing to make a few extra passes.
The SJ 4000 grit Japanese wheel will deliver bragging rights for a highly polished edge. My typical kitchen knives seem plenty sharp with a carefully used SG.
Keep posting!
Ken
Posts: 25
Threads: 11
Joined: Jan 2018
Thank you Gentlemen!!!
Am I correct that a Bess Score of 150 is about out of the box factory score in many cases?.....I guess I was hoping that something better than factory was easily acheiveable.....
Posts: 504
Threads: 55
Joined: Feb 2017
Sam,
Here is the official chart. BESS 150 is noticeably sharper than factory new for fine cutlery.
http://www.edgeonup.com/eou_new_2016_008.htm
Ken
Posts: 43
Threads: 4
Joined: Feb 2018
I agree that BESS 150 is sharper than factory new and that it can be routinely achieved with just the SG250 stone and the leather wheel. This last summer I did a stint as a knife sharpener at a couple small, local farmers markets. I used the SB250 and SG250 stones and the leather wheel and was not satisfied with a knife suitable for delivery to a customer unless it was under 200 BESS. At home where time was not an issue, I was able to routinely get edges in the 90 - 130 BESS range.
Rick
