Grinder for Sharpening - Questions

Mitchell Knives

Mitchell Knives

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I'm considering purchasing a grinder to use for sharpening and reprofiling. Some of my knives have edges that are too thick or damaged and I would like to be able to correct this. I have tried diamond stones, but this is still too difficult and time consuming.

I found this grinder online:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=2485

I'm guessing that this grinder will be adequate since all it will be used for this sharpening/reprofiling. My local Lowes also has a Delata belt grinder for $100.00. Is the $30.00 grinder adequate for my needs? Has anyone here used one?

How does one ensure that the sharpening angle is constant when using a grinder? Is there some sort of jig available? I would like to be able to sharpen at various angles for different types of knives.

Any tips or suggestions?
 
Jonathan

That is perfect for entry-level grinding and sharpening. Many of us learned the basics of knifemaking on the exact same thing. And for $30, it's a steal. By the time you wear it out, you'll outgrow it anyway, so it's definitely worth it.

Get a wide spectrum of belts, including a leather belt from www.leevalley.com (Lee Valley Tools) - can't imagine life without one. Order the rest of your belts from Discount Abrasives - absolute cheapest in that size - www.geocities.com/discount_abrasives


Anyway, do a search on "grinder" and "sharpen" and you'll find a lot of information in this forum and the general blade discussion forum on this very subject.


Best of luck!

Dan
 
pendentive,

Thank you for the links. The Lee Valley site seems to have everything I was looking for. I'll order the $30.00 grinder ASAP. If I like it, I might even consider trying to make a knife.

I did a search, but I can't find any info regarding how to keep the sharpening angle constant with a belt grinder. (I'm used to sharpening with a Spyderco Sharpmaker with it's set angles.) Is there any way to accurately grind a certain angle you desire with a belt grinder or is it all freehand work?
 
I got that same sander!

I got it for about $100 nearly 5 years ago...

she has been a bit of trouble for me,,,due to the fact that I have ran that poor girl to death,,,Im on my 3 switch...

I had a problem with the wood dust collecting inside it, then catching fire when I sanded on some steel....

there is a dust connection where a shop vac can be connected,,,and thats a very good I dea when sanding any type of wood.

I use my 1x30 sander all the time to work the handles now,,I love that sander,,,but she is a bit of trouble from time to time.....
 
No, that is not it. The one I am talking about slips over the platen and is adjustable.
 
It is called a universal angle guide, Cat. # AG101/ 1" Universa Angle Guide= $15.95 retail
 
I did a product search on that number and got nothing. Do you think it will fit my craftsman 2 x 42? If not do they make a guide that will? Lets just say my freehand grinding needs some work, but i dont like having to scrap steel just because of that.
 
I've got that same grinder. The first one they sent me broke the first time I turned it on (the plastic tracking wheel inside cracked all to hell and flew apart), but they were very good about replacing the whole thing, and were quick about it too. Now I use it exclusively with a leather belt coated with buffing compositions (similar to Tripoli) for "stropping".
Also, I caught them on a 'free shipping' deal, so I really feel like I got a good deal.
 
I'll be honest, I have this one and a basic delta model that's pretty much the same setup. I think the delta was about 20-30 bucks more and it's a much nicer machine. Both work fine for light work. The delta just seems to run smoother.

Tim
 
Holding a constant angle with a grinder becomes quite easy. You should get a few practice knives from a thrift store. When grinding, you want to lock your elbows to your side, and move your body to move the blade. So with your body all locked in tight, really look at the angle of the bade as it approaches the platen. 90 degrees would be with the spine level with your chest. 45 degrees would be half way from the level position, and the angle of the platen (vertical). cut that in half again, and you have 22.5 degrees, pretty close to the 20 degree sharpmaker angle. Try setting up the knife this way (hold it horizontally and cut the angle between the horizontal and vertical in halt, then cut that angle in half again), and sharpening. raise a burr, and do the same on the other side. Try it on a few practice knives, and then you'll have no problem hitting the 22.5 degree mark. From there, it is just a matter of looking at the angle of the knife in relation to the platen. You'll be able to quickly make a pass and look at the scratch pattern to see if you need to go more or less acute with your angle. I think $15 spent on an angle guide is better spent on a few practice knives and an hour behind the grinder (with money left over, I might add). With reprofiling, the exact angle isn't all that important anyways. You want to hog off the shoulder, which is behind the edge. Thin this area out and then grab your sharpmaker and put an edge on the newly thinned knife (Juranich calles this grinding relief in his Razor's Edge book, for all of those who has read it).

Enjoy!
 
Thanks Crayola. I'll try the method you described and see how it goes. All the factories seem to sharpen freehand with great results.
 
I asked about a week ago about building a cheap grinder for sharpening and finishing. The above 1x30 grinder was recommended. I bought one today on the way home from work and tried it out on some kitchen knives. Worked like a charm. I sharpened a machete, butcher knife, fillet knife, multitool blade, and a Boye folder in about 30 minutes. Just ground a relief with the grinder and finished on the sharpmaker. I was a little over excited and tried it inside, but I wont do that anymore. Its a little dusty. The 80 grit belt it came with leaves a pretty course finish, so I'll probably order some finer ones from Lee Valley tools. The leather belt is probably a good idea too. At any rate, I'm very pleased with the results and with some more practice, should be able to do just about any of my knives. Thanks for the advice. I wish I'd known it was this easy with a sander before I spend so much time and money on diamond hones and a course Norton stone. The diamond sits on a shelf, but the Norton is still used for quick sharpening of friends knives and the machete above.
 
congrats me2! Did you sharpen against the platen, or in the slack portion above the platen?

For everyone's benefit, could you mention how easy (or hard) it was for you to get a good angle? That question was brought up, and it would be great to hear a response from a guy who's grinder is still brand spankin' new!
 
Originally posted by me2
I wish I'd known it was this easy with a sander before I spend so much time and money on diamond hones and a course Norton stone.
Click to expand...
This is why I make the comments I do. Once you've "crossed over" the difference is night and day.

Originally posted by mlawson
Do you want the edge faceing into the motion of the belt or away?
Click to expand...
Edge-down when sharpening or stropping. You only have to try it once the other way to be convinced...:eek:
 
Getting a good angle was fairly easy. I had been using a belt without a grinder for a while, which helped. The trouble I had was with the tip. I rounded off the fillet knife, but was able to put it back. After that, it was easier. At first I was doing the pass across the belt too fast, and lost control. After I slowed down, it worked better, and I didnt round off the points as bad. The machete was a little tricky, because it is so wide and the distance between the spine and belt is different. I just took the table and platen off.
 
Does anyone worry about burning the temper out with these cheaper fast running belt grinders? I would guess it could be fairly easy to do thin steel like on the edge heats up very fast.
 
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