Sharpening With A Belt Sander?

[Chef niloc]

I do a lot of my knives on a belt sander (modified for knife grinding) but have never done a round knife this way. Anyone here sharpen round/head knife this way? Seen any YouTube videos or any others? Better yet a video of a knife maker makeing one?

[oldtimer]

I´m using a belt sander to sharpen my round knives, 120 grit sanding belt, plus a felt wheel for honing and polishing the edge.

/ Knut

[Art]

While I have Burr-King and Bader belt grinders, I prefer to use a 6x48 grinder with a Norton Blaze ceramic belt in 60 and 80 grit for profiling; but just to sharpen a really dull blade, I use a 120 grit Blaze. I work with the belt running away from me. These belts cut like lightening so if you are on there more than a few seconds you will overdue it. After that, I use DMT diamond bench stones, although the natural stones work well too.

Now a days (not back in the stone age when I was making) a lot of makers order their blades water jet cut to their specifications. With head knives, it is just a minor bit of work on the edge profile up to whatever finish suits you (120 or 240), then off to heat treat. Finish work takes the time.

There is a lot more work for thicker knives both in profiling the edge and finishing.

With head knives, water jetting allows you to maximize the sheet of steel, whereas the old fashioned way sacrifices a lot of steel to the grinder.

Art

I do a lot of my knives on a belt sander (modified for knife grinding) but have never done a round knife this way. Anyone here sharpen round/head knife this way? Seen any YouTube videos or any others? Better yet a video of a knife maker makeing one?

[Chef niloc]

Thank you for the info

When approaching the belt do you start in the center first or go right to left, or hold the blade so the tips of the knife are runing up and down?

[Art]

6x48 belt grinder with the table laid down flat. From the end that isn't connected to the base and the belt running away. Hold the handle (or tang with vicegrips) approaching the belt at a 15-20 degree angle. I go from one tip to the other and possible back, then I flip the knife and do it again, that's all you will need to set the edge unless it is that CPM 35 V stuff, then you might need more. You just need to set the edge and get a burr, then you go to stones. After stones, buff or strop with green chrome compound. Since I know what I am doing, I use a couple of fingers of my off hand on top of the blade and apply pressure that way (not a lot of pressure). My fingers also tell me how much heat is in the blade.

Art

Art

Thank you for the info

When approaching the belt do you start in the center first or go right to left, or hold the blade so the tips of the knife are runing up and down?

[Chef niloc]

These pictures might help? What way is right, A or B?

A)

[bruce johnson]

Colin,

I use a regular 4x36 benchtop belt sander. I am mostly not needing to profile from a blank. Any major profiling I use either a heavy grit like 120 or diamond stone spending on how much there is to do. I do my final edge on a belt sander. I have some fine grit belts and some pretty wore out ones I use. There used to be a youtube video of how I do it. I take a piece of scotchbrite pad and put in under the supported part of the belt. A pice of duct tape front and back holds it in place. This makes a little cushion under the belt and I let it run wit out tension. It has enough slack to let the blade in a bit and end up with a slight convex final edge, sort of like an infinite angle secondary bevel. I also have a 1x30 belt sander. It is easier to buy fine grit belts for it. I get them from Lee Valley. I use it in the slack part of the belt close to the top wheel. I just keep chasing burs with finer and finer grits until I get a clean edge and then do a final strop with green. I keep a finger on them like Art does to watch for heat.

I just saw your other post. For no particular reason I go from point to point and back, then flip over and the same on the other side. I watch for a uniform bur and then go to finer grit.

[Art]

B is correct, although I have never tried A. On a thicker blade knife, Bruce's way is better as it leaves more metal behind the edge. Seems that everyone likes the 1/16 inch thick blades these days, with those, I don't think you can get a good convex (I call it a teardrop) edge on it, but it won't hurt to try. I use a different method for slack belt, I cut an inch out of the platen and use the area between the top roller and the platen to get the teardrop shape.

Art

These pictures might help? What way is right, A or B?

[Randy Cornelius]

I have a leather belt that I made for my 4 X 36 belt sander that I have green rouge on that I use all the time, sort of a power strop. Love it.

Randy

[Lippy]

Randy,

Tells us about making your leather belt strop. I'd like to make one for my Harbor Freight 1 x 30 belt sander. I'm not trying to hijack the thread as I think this is still dealing belt sander sharpening.

Cheers and thanks.

[gtwister09]

SurgiSharp carries the leather belt for the 1X30. A couple of places where you can find these is USAKnifeMakers and Woodworker' Supply. Make sure you remove the leather belt from the sander. If there is tension on it then it will stretch.

The Scotchbrite pad is also a trick that glass/sandpaper sharpeners use to create a Moran edge as well. I started out with the Scotchbrite pad on the 4X36 also but found an insert called the Belt Lift that does the same thing. I still use the 1X30 a lot or I should say that the neighborhood uses my 1X30 a lot.

Regards,

Ben

[Chef niloc]

I get most of my belts from , they have a great selection. The leather belt they sell is the surgisharp.

http://www.trugrit.com/belts1.

For the belt I like to use a green chrome diamond mix compound that I made my self. I took a bar of green compound melted it, added the diamond dust and stirred it till it got to thick to stir. Then I stuffed it into a Papper towl tube and let it cool over night. the diamond make the job go quicker and on harder steel, I also think that diamond compounds give a better "feel" to a cuting edge.

http://www.diamondte...2_4_micron.html

This is the best green compound I have found, 100x better then the barkriver stuff

http://japanwoodworker.com/product.asp?s=JapanWoodworker&pf_id=01.098&dept_id=13100

Edited November 22, 2011 by Chef niloc