Paper wheels

H

handyman720

Joined
Jan 19, 2008
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Have noticed no one talkes about hard felt wheels for sharping knives?? any reason for that. also was wondering why the speed for them is in the 3000 rpm area. always thought the the magic number was about 1750, atleast for stone wheels. someone had mention using a 1X30 belt sander and the speeds are very high with those also, so was wondering just how much heat it would produce on the blade...could use some help on this subject.
 
I run my paper wheel at 3400 rpm, but I keep the blade moving and do not dwell in one spot. There is some heat build up, but nothing that will degrade the blade's quality. 1750 is more controlable if you do not sharpen on a daily basis.
 
i have always ran my paper wheels at a slower rpm. i have tried it at 3450 rpm but i just like running mine at 1725 rpm. they still work at 1750 but you need at least a 1/2 hp motor. as for the felt wheels, a friend who was a maintainance man for a company that buffed a lot of parts liked the edge the paper wheels put on compared to felt wheels. to sharpen a 3" folder takes about a minute or less which would be considerably longer with a felt wheel.
 
To avoid rounding off your edge you want a fairly stiff wheel. Paper is stiffer/harder than felt. A sanding belt stays cool and pulls more heat out of your blade as it works than most wheels. You still have to be careful, but the belts work better than you might expect.
 
Just a note to say i appreciate the feedback on the paper wheels,felt wheels and belt sanders...have to check and see what motors i have hanging aroiund and see what i can do...rgs chuck.
 
jeff, you are 100% correct about the hard wheel being better than a soft wheel which can and will round off an edge. one made from "cardboard" is too soft to do what the paper wheel does, i have seen a knife sharpened on "cardboard" and it wouldnt even shave hair. you might get lucky on a few knives but you can get consistent results from the paper wheels. a felt wheel would scare me too since the chances of a knife tip catching would be just as great.
 
richard j said:
jeff, you are 100% correct about the hard wheel being better than a soft wheel which can and will round off an edge. one made from "cardboard" is too soft to do what the paper wheel does, i have seen a knife sharpened on "cardboard" and it wouldnt even shave hair. you might get lucky on a few knives but you can get consistent results from the paper wheels. a felt wheel would scare me too since the chances of a knife tip catching would be just as great.
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I don't trust this anecdote. I consistently see knives sharpened on cloth wheels, softer and more compliant than any paper or cardboard wheel, that get as sharp as any razor. In fact, I can't think of any sharpening system I've used that won't get fantastic results. Sharpening a knife isn't rocket science. It seems most folks who have trouble with it are simply not clear about not only the "hows", but the "whys" of sharpening. Blaming the tool is not the answer. If one cannot sharpen a blade, 99% chance that it's user at fault, not sharpening tool.

Jeff Clark said:
To avoid rounding off your edge you want a fairly stiff wheel. Paper is stiffer/harder than felt. A sanding belt stays cool and pulls more heat out of your blade as it works than most wheels. You still have to be careful, but the belts work better than you might expect.
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Any sharpening medium can round off an edge if the knife is held incorrectly.

Also, I find that sanding belts don't seem to be any cooler than cloth wheels. My belt sander is fixed at about 3400 rpm. If the abrasive is enough to generate sparks, it's more than enough to generate too much heat. To reduce heat, run at slower speed and make sure the belts are not worn. Worn belts generate too much heat by friction and simply cut inefficiently.

Regarding wheels, another factor to consider besides RPMs is the diameter of the wheel. A 6" wheel running at about 3000 rpm strops about the same as a 10" wheel at 1750 rpm. Running that 10" wheel at 3000 rpm may theoretically work faster, but it may also be out of your safety zone, and out of the wheel's spec.
 
I have used the hard felt wheels for years as the last step in sharpening a blade, they work well as a powered strop , I mostly use the 1/2" one.
Richard
 
shecky, i worked at a factory that made aircraft lights and guys who buffed for years always used a hard sisal wheel for sharpening, not a soft cotton buff. i'm sure these guys had more experience than you. a soft wheel will have more of a tendency to round over an edge than a hard wheel. i have a hard cotton buff but i'll never use it for sharpening when i have a hard paper wheel that will do a much better job and a lot faster even running at a slower speed. the paper wheels are made to run on a high speed buffer safely. i have test ran my 10" wheel at 5420 rpm to see if it was safe at a higher speed which it was. i have my belt sander running slow and it has less of a tendency to generate heat than a faster running belt sander. handyman, you'll love the paper wheels if you get a set. they will get your knives sharp in minutes compared to longer with cloth or felt wheels and belts
 
richard j: All that's well and good, but none of it negates my points. Rounding edges is a is possible with any sharpening medium and as such is indicative of user's skill more than anything.
 
The softer the sharpening medium, the easier it is to round the edge. Simple as that.
 
a felt wheel will roll an edge quicker than a paper wheel will. there is just too much give in the felt compared to paper. if you had a blade held at the same angle by a jig, the felt would roll an edge before the paper ever would. thanks broos for your post :thumbup:
 
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To prevent rounding of the edge lower the angle you hold the blade at. So softer means lower it is all how you do it. Grit size and edge angle for the most part is what determines how polished/sharp the edge will get.
 
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