Hello guys,
I want to sharpen all the knives I have. Normally I use some knife sharpeners from the store, those are abrasive metal plates where I rub the blades on.
But that takes some time. In my grandpas workshop I found this grinder. The left wheel is seemingly out of rubber, but still rigid.
Also I found a green block of something that looks like dried up clay. (more Pictures follow)
Can I use that grinder to sharpen my knives?
And is that green stuff the buffing compound?
A more closer look on the wheel.
And the green stuff
>>918623
Yes and yes. I sharpen lawnmower blades, knives, sickle, etc. on my grinder. I even form stain glass shapes via my grinder. Love my grinder.
Without a practiced hand, youll ruin any knife youll try to sharpen. That set up on that grinder is for polishing. They make electric knife sharpeners that you can buy that will sharpen the average knife in about 2-30 seconds.
>>918651
I dont want to buy anything. I could use those manual sharpeners, but thanks for the warning.
I'll try my skill on an old knife first.
>>918651
OP already has a grinder, it is not hard at all to sharpen a knife, all he needs is a fine stone grinding disc to attach.
>>918654
It does not take long to get the feel and figure out the angle on both sides to sharpen. You will do fine.
Not OP, but anyone here have any good tips on sharpening on a wheel grinder? I got some chisels I need to put a real edge on and no whetstones .
>>918662
keep it cool, and lookup some angle guidelines
>>918628
Yes, this is definitely polishing compound and your wheel is a felt wheel for polishing. Jewelry, knives ect, you can polish them.
>>918698
Thanks. I knew my grandpa had stuff like that.
However I read at first I could polish jews with that. My times on /b/ really show.
its difficult to get really consistent and accurate angles on a grinder. its good for rough sharpening, especially on less delicate things like axes and lawn mower blades etc but for knives you want to finish with stones and leather for the sharpest edge.
Never, ever use a power grinder to sharpen knives. At least not any you care about. The heat from the grinder will ruin the heat treatment of the blade. The result will be a softened blade that dulls or folds over extremely fast.
Don't do it.
Ever.
Ever ever. Ever.
The cutting edge is very, very, very thin. You won't be able to prevent it from heating up, even with years of practice. Ain't gonna happen.
So don't do it.
Unless you have a liquid cooling system like on a CNC machine or something. That'd be ok.
Also unless it's a shit knife you don't care about, like a lawnmower blade or something. That's also ok.
Otherwise, use a file and sharpening stones by hand. Don't ruin good knives. Do it the old fashioned way.
>>918761
Then I will ruin a bad knife first and see for myself. If I get the idea that you are right. I will do it the old way.
>>918623
I sharpen all of my knives on a grinder with a paper wheel. http://sharpeningmadeeasy.com/paper.htm. I dont think your set up will work but its worth a try. picture should give you a general idea on how to hold the knife to get a consistent angle.
Well. THanks for the all the input guys and girls and aliens.
I will try it out tomorrow and report back my findings.
I guess the thread should live that long, when not I am opening another.
Thanks 4chani read the thread and tried this. Grinder grabbed the knife, hurt my wrist and stabbed the knife through the guard. I'm gonna go change my pants now.
>>918623
personally use japanese water stones. Are they worth it? NO, not at all. But now I own them and I get every cutting implement razor sharp
>>918623
Just get a lansky guide rod system. Or, since you obviously don't give a shit, get one of those v shaped quick sharpeners.
>>918761
10,000% this.
Also, you can get water cooled grinders and belt fairly cheaply.
>mfw all the local places around here use uncooled bench grinders with regular grinding wheels to sharpen people's knives
>>918804
I was brushing an aluminum rod with a bench grinder wire wheel. All guards and safety gear in place on the machine and on me. I stood to one side of the wheel as I was working on it. Suddenly, the wire wheel snagged the rod right out of my hands, spun it twice inside the shield around the wheel and shot it out of the guard and through the wall. It was sticking out the other side of the wall in the next room.
Always stand to one side of big/fast spinning things. Had I been standing in front of the wheel the rod would have hit me square in the chest.
>>918835
I saw aluminum and was about to rage at you for grinding aluminum. Then I saw wire wheel.
You'd be amazed at how many idiots try grinding aluminum, then wreck their wheels/machines and try to claim warranty on it. Used to work retail at Sears and would see at least a dozen cases a year.
That flap wheel on the right will do for coarse stock removal as on lawnmower blades, and because it is a flap wheel you can also use it on aluminum etc without risk. I like flap wheels and have many for die, angle, and bench use.
DO NOT face edges AGAINST the rotation of flap wheels, as OP obviously found out.
The wheel on the left appears to be a specialty wheel with a band around it. Some are used to hold circular abrasive bands. Fine ones can sharpen tool edges but fine grinding wheels are inexpensive and work well. Have a cup of water handy to dip chisel tips in so they don't over heat and be GENTLE.
>>918859
Hey, I am OP and I didnt even turn that thing on yet. It is 2:30 and I just finished watching The Revenant. Good film with a shitty end.
But like I said before I am not gonna turn that thing on before tomorrow, because when I first posted my mother was already in bed and she aint feeling good.
So I didnt want to wake her up with the noise.
And because I was lazy.
I didnt fuck up, yet.
>>918859
I tried to make it sound like I wasn't op, I had 'just' found the thread.
And it wasn't actually this thread, I had the idea last year.to polish my knives to sharpness, but... things got scary.
>>918893
Derp. And I just got some high grit water stones and they're great and don't even take that long to work up to.
OP here.
Set up my machine and are ready to go.
>10 Minutes later
So I did all the blades I wanted and the results are mixed.
Some blades turned out really well, some bad. I guess it is up to the angle you hold em.
I agree with most that doing the old way with a grinding stone is better if you want a really sharp knife. Or if you are good and want too sharp a knife often you can use a grinder.
But the chance to fuck up are higher, for example I made one blade so thin parts chipped off, yet it became the sharpest blade of all.
My result is, I am not gonna grind my knives on that thing again, but rather tools or just things who have to be a bit sharp, but not much.
Also you have buffing compound stuck on the blade which is not nice for cooking knives.
And grinding and cleaning takes as much time as just taking a grinding stone or whatever else.
>>919062
So I sepnd the last 40 minutes regrinding all my knives with a cheap ass metal grinding plate.
And now all knives are really sharp.
