This thread came back to my mind this week. I had a gentleman send me two knives, a folder, and a straight knife, and wanted me to put convex edges on both. Now, the folder was a popular "mid-tech" model, and the straight knife was from a "custom" knifemaker. The folder had a decent primary grind on it, and fairly small edge bevels, which made the change to a convex edge pretty simple, and having cut with it before and after the conversion, improved the cutting resistance/performance noticeably.
However, the straight knife was a totally different story. The blade was a full 1/4" thick for it's entire 4 1/2" length. It was supposedly "hollow ground", but looked like the "hollow" had been ground on a 4-6" contact wheel, and had enormous edge bevels. I tried to measure the "flats" on the edge bevels, simply because I've never seen any as large....the best I could measure was approx .120" flats on each side of the edge...nearly 1/8" flats on edge bevels? WOW!!! Now, this much edge bevel CAN be convexed, but there's not much point. Even with a convex, any edge that is left that large prior to sharpening is basically a cold chisel. So, I got on the phone to the owner and explained the issue. He just didn't get it. He kept saying..... "but if you convex it, it will cut so much better!" I told him that in order to correct the issue, the blade would need to be reground, and that I simply would not do that to another maker's knife, no matter how poorly it was done the first time. I also suggested that if he was unhappy with it upon return, that he should contact the maker with his concerns.
The moral of the story? There's a couple.....
If you're creating a knife, make sure your steel, and it's heat treatment are correct to produce a grind that is thin enough to cut well, without chipping/being damaged. (I'm pretty certain the straight knife I spoke of was left overly thick at the edge in hopes of preventing chipping/damage to the edge). NEVER try to correct another makers mistakes! (such as refusing to regrind the knife like I did). Make the client go back to the original knifemaker for anything major...otherwise you will trap yourself in a bad spot between another knifemaker and a customer/client.
OK.....back to our regularly scheduled sharpening discussion.