Most people have at least one scar from a grinder all it takes is one thread dangling from a sleeve and an abrasive wheel :D

Yes i am a victim of this video already ;(

Thanks for good infos!

for example japanese stones use a different grit system than the west. I tend to start with a 240 grit belt and go up to 600 (not always), and then strop on some leather. This angle grinder method above is a way to get yourself injured (look at the direction it rotates), even a belt grinder needs to be used with caution. Last year a very experienced knifemaker from the US died when the belt caught the knife. Just use sandpaper and some patience if you don't want to invest much. It works fine.

If there is color change that means you messed up the knife very badly. You don't need to go that far to loose some points of hardness and reduce edge durability. According with tempering diagrams 200 degrees is enough to start loosing hardness on most steels. If it's sending glowing sparks the apex is clearly overheating.

@@thiago.assumpcao but also remember that's just the sparks getting hot. Not to mention literally every knife maker I've ever seen make a knife does the majority of the grinding before heat treatment and tempering yes. However they brought grind to a point, they then need to finish the grid to the final thickness and final finish grit they want. Each one of those belts will send sparks out after heat treatment and tempering. Then on the Japanese kitchen knife side if things. They forge, heat treat and temper before any grinding. Then rough finding on water wheels because it's heavy grinding and you're bound to overheat the blade with any form of heavy grinding when not cooled but the water wheels still cause sparks. Then over to the finishing grits which are done differently depending on which maker the knife is done by. Normally either on belts, which produce sparks, or on large buffing wheels which also happen to cause sparks as they take the knives up to about 180 to 200 grit on those buffing wheels. The finishing of the Japanese knives are done without any water cooling and yet Japanese kitchen knives are known as some of the hardest knives out there. While what you said about 200 degrees being enough to start to change the hardness may be true its doesn't affect the edge adversely in any noticeable ways unless you're doing something wrong.

@@tylermelton1746 Sparks dont heat up after leaving the knife. They get that hot during abrasion while in contact with the knife. Heat dissipates so we dont see it on the entire knife. Heat treatment damage by machine sharpening without color change is not only a theoretical issue. Some knives look perfect but don't get a good edge no matter what you do. After grinding off a fair bit of steel knife changes behavior and cuts better. On a less severe case you may have a good initial sharpness but loose edge durability because of hardness loss. Detecting such issues would be quite hard unless you do durability tests. Machine sharpening without water cooling is possible but doing it right takes a lot of time with constant water dipping. Water cooling saves a lot of time.

@@thiago.assumpcao of course it takes a lot of time. But the point I was trying to make is to get that issue you need to be doing something wrong. In this case that would be not regularly cooling the blade. In the case of a grinder fresh disks or belts mean you have to dip less.

Are you guys saying if there's sparks you've gone too hard and it's over tempered the knife and destroys the edge? I just bought a belt sander to sharpen my knives. Didn't think it would soften the edge

it doesnt matter the knife still isnt sharp at all

дорогие ножи болгаркой никто не точит.я брату отдавал в профессиональную заточку на профиле ,заточка лучше заводской и держится дольше.

Точно.. Совет для идиотов. Хотя на этих ножах метал дрянь. 40Х13, и из листового штампуют. Твердость от силы 55 единиц.

Nói xạo . Mài thế quăng luôn dao cho xong

Слышь , мастер с дивана , ты сам то ножи точил без воды ?

@@user-pf7qc9pz4g точил на сож,

@@user-pf7qc9pz4g я кстати только сейчас этим и занимаюсь,60-70штук в день,через мои руки проходит,ножей,топоров

The guard just gets in the way. I took my guard off the day I got the tool. You don’t need them unless you are a novice with an angle grinder.

I wish I had watched before I bought all them belt granders

This is the worst knife sharpening I've ever seen. Please do not try this at home.

Привет 🤝 Да ему вааще не надо точить ножи... При Наличии такой разделочной доски.... 😂😂😂

Full disclosure!! This is not for little bitches. I repeat, this is not for little bitches. So if you’re not a little bitch, then please excuse @daddydayne little bitches comment

Это верно!! Пилить будет только 3 помидорки !!)))

ok on a cheap knife maybe , wouldnt want to remove that much material of my knives though really but interesting video .