The question came up about the best tool to learn with. The tools mentioned were knives and chisels. As most of you know, I am firmly in the chisel camp, even for those who usually sharpen knives, specifically, a 3/4" Irwin blue chip chisel. I don't recommend cheap beat up chisels which are, in my opinion, more difficult to sharpen.
I feel the same way about cheap, beat up knives from the thrift store. Here would be my first choice as a learning (and using) knife:
https://www.amazon.com/Victorinox-5-2003-25-Chefs-Knife/dp/B08WXV2BRF
It is well made with good steel. It has no bolster obstacle. It is an easily used size and reasonably priced. It also happens to be one of my most used knives in the kitchen.
My first choice for a learning tool is still the chisel. However, if I did not have a chisel, this knife would be a good choice (in my opinion).
Ken
I bought mine primarily for wood working tools but with an eye for knives and axe and possibly scissors and garden shears.
I didnt want to learn on my chisels and plane blades, my chisels are marples with boxwood handles and about 40 years old so i practised on the chisels i inherited from my father in law which are historic steel from firms that are no longer around, so they are good steel but the thing that i quickly learnt was that they were not square and i had to experiment with the jig to get a square edge. Stigs tip for alignment is good and i will revisit that as i ended up putting them in the centre with the centre line.
My kitchen knives are mainly sabatier type but from independent manufacturers but all with reasonable steel.
I agree with you. I would not want to use nice vintage Marples chisels as learners. (I wouldn't use my grandfather's Stanley 750 chisels as learners, either.) My learning chisels are the Irwin version, not the same quality, but very reasonably priced. I gradually acquired around ten of them, all 3/4". The large bevels are easy to see when comparing scratch patterns.
Back to the class, Sebastien demonstrated Stig's tip of holding the chisel (mounted in the jig) against the side of the grinding wheel. I haven't tried it yet; however, it seems to have potential for keeping the grinding square.
Ken
I think I would start someone out on the 8" knife. This is more in line with the chef's knives most people will bring you and it too is relatively easy to learn on. Another benefit is that you will have an inexpensive knife that is exceptionally sharp for your own use. Since I don't worry about knives/hour I also use a knife like this for rudimentary knife skills and steeling lessons. I would hate to see a customer lose their fingertip. I also reinforce these lessons with my granddaughters when we cook together. Currently they are in a baking phase so not much knife work.