Instructables

Quickly Sharpen a Knife...with a Dremel!

Ever needed a knife sharpened really fast? Well you have come to the right Instructable! This Instructable will teach you how to sharpen, and clean up, a knife with a Dremel!
 
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Step 1: Items Needed

Okay so first off you will need a couple key tools and objects.

Tools:
  • A Dremel.
  • A vice or something to hold the knife while sharpening.
  • Some Dremel bits. Part No. 932 -- A Aluminum Oxide Grinding Stone -- Part No. 401 -- Mandrel -- Part No. 414 -- 1/2" Felt Polishing Wheel -- Part No. 421 -- Polishing Compund -- ( Part Nos. 401, 414, and 421 are optional. Only get these if you want to polish your knife.)

Objects:
  • Safety Goggles.
  • An old, or new, blunt knife.

Step 2: Start your Dremel!

Okay so by now you've found an old blunt knife somewhere. I really don't care how you found it just that you found one, and you've probably gotten those parts or it would really be no use in reading this Instructable...anyways, lets get started.

EDIT: When I cut it at a 25 degree angle the blade wasn't that sharp. So after a few tries I decided to cut the angle down to 10 degrees.

1. You should put the Aluminum Oxide bit in.
2. Put the knife in the vise.
3. Start the Dremel up.
4. Grind away at about a *10* degree angle.
5. Turn it over and grind that side too.
6. On to the buffing!

Step 3: Optional: Buffing the knife.

Okay so if you clicked on this step you probably are either curious or want to clean up your knife.

This is where the Parts 414, 401, and 421 come into play.

So...screw the 414 into the 401, then rub some of the compound onto the buffing bit.

Buff away!

Step 4: Done!

Now you have an extremely sharp knife. Well depending on how good a job you did.

Ideas...

1. You could resell the knife to a friend, for more than you think it's worth. -- Just because of its good condition. --
2. Use it.
3. Give it to someone as a cheep birthday preset.

Remember: Safety First!

-- Taylor G.
Tronclay11 months ago
I have to disagree with Denger. I love my dremel and after using it for many projects for years ive become quite good with it and one thing you learn is that a soft touch gives you the best results. Using the proper speed and proper bit is key. I have many knives ranging from a couple bucks up to a few hundred dollars and although i wouldnt usually use a dremel on a "fancy" knife, it works great for knives you actually use. The blade heating up has not been a problem if, again, you use a soft touch and the right bit. Any heat that builds up can easily be taken care of by touching the blade against a cold surface for a few seconds, as long as the heat doesnt get VERY high then theres no change in the metal.

Why would i spend a half hour using my stones to sharpen a small, hard-use blade when i can do everything from redefining to honing and even using makeshift home made strop bits to smooth out my edge and do it all in 5 or 10 minutes and get right back to work? It would take a fair amount of negligence and/or inexperience with a rotary tool to PERMANENTLY destroy a knife with it but that being said it does require more care than using stones and I would certainly recommend practicing a lot on knives you dont care about first, then moving up to your user knives.

P.S. A lot of budget knives (50$ or less, walmart stuff like Buck, Gerber etc..) arent ground out all that well and the factory edges often leave a lot to be desired. Ive reprofiled my fair share of cheaper knives and a dremel does a great job of that as well. Explore the dremel my son, its power will enlighten you.
Denger1 year ago
With all due respect, electric grinders of any speed should only be used on a knife you don't care about very much. They will quickly and irreparably damage the knife blade. While they are faster, grinders are extremely poor substitutes for hand sharpening with mill file, stones, steel or ceramic crock sticks and a leather strop. Sharpening by hand with the proper tools & techniques will actually improve, rather than permanently destroy, a knife's original factory edge.
2 stroke 3 years ago
i use an angle grinder not recommended lol i dont have a dremel
you should never use a rotary grinder on a knife, it heats the blade up and the edge will loose the temper
2H2H5 years ago
cool I got da same knife there blades get dull very very very very very very fast compared to my Gerber abd my Switchblade.
milano-stiletto-switchblade-black.jpg
N467RX5 years ago
The best idea to start is to use utility knife blades (non-snap type ones), that way if it gets damaged you can replace it for cheap ($2 for a 5-pack or so).
im_tux6 years ago
nice idea but there are carbide sharpeners that work well for about $5 qand wont damage the blade. they work fast and put a 25 degree angle so they stay sharp longer
kevinlee6 years ago
Take care not allow the knife blade to get too hot or the metal will loose temper and it will dull very quickly. Also the angle you get using the lawnmower blade sharpening attachment works pretty nice if you sharpen both sides.
you should grind the edge to total 25 degrees, so like 12.5 degrees on each side. and statistics say people overestimate angles by 5-10 degrees, so what looks like 12 could be 20 on each side, and then you could come out with a 40 degree blade, and that would be pretty blunt. other that than that, nice idea. i never thought to try that, although i could see how a beginner could easily screw up a knife.
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