Starting with a belt sander

V

Vicv

Joined
Aug 22, 2011
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ok so I've gotten ok with freehand using king and naniwa stones. Unfortunately I find them too slow. It's not my time I'm concerned with it's I just don't have to patience to be hunched over a table for half an hour without seeing any real results. My Lansky also takes a long time to use and I've never been happy with the results and limitations. So today I bought a 1"x42" belt sander from Lee Valley. I havn't gotten a motor yet so I still havn't tried it out. I do have a few questions though. I've also bought an 80, 60, 40, 20, and 9 micron 3m micro finishing film belts. Also a 15 micron silicon carbide belt. A leather belt I've charged with veritas green compound (.5 micron) and the belt it came with ( a P120 blue zirconia belt ) which is around 125 micron which I'll probably never use unless I have a seriously damaged lawnmower blade or something. Ok so after all that prattle one of my questions is with the silicone carbide belt I believe that's a friable material so it will get finer with use. What micron about will it become? And do I use it before or after the 9 micron belt. My second question is by looking at the wonderful "Grand Unified Grit Chart" ( very helpful btw) the 9 micron belt is around a 1200 grit japenese stone. Now that's where you usually start when sharpening with those stones if there's no serious damage to the edge. Then I'll be going straight to .5 micron charged leather. the 9 micron belt seems to be the finest I can find. Isn't that a very large jump? Also unless I do have a damaged blade doesn't that make the other belts I got almost redundant besides the 9 micron? Because if I can make the jump from 9 micron belt to .5 leather that's like going from 1500 shapton to 30,000 with no intermediate steps. I know because I'm using a motor it speeds up the process but it just seems to me like I have too many courser grit belts and not enough stages in fine ones. Sorry about the long post and having questions scattered all over the place but wasn't sure how to order my thoughts on this and just obviously started typing. Anyone who can can it would be greatly appreciated
 
I bought all my belts from lee valley, so they're on the site. You want to start with a super low grit to set the bevel, because you're putting on convex on it with the belt sander which is not the same as factory edge (in most cases). I start at 40, then move to 80, 120, 240, 400, 800, 1200, 2000, leather w/paste. I might have something between the 1200-2000, don't remember off the top of my head. It gets a mirror polish at 800 though. Im not really sure of the micron conversion, google would likely be a good resource. Hope that helped!
 
Bear in mind that the GUGC is only a VERY general reference to help sort things out a bit between systems. The belts tend to cut quite smoothly on metal, with a lot less big scratches than you might expect from their grit size. Personally, if I was going to do that, I'd probably drop from 9u to 1u Boron Carbide if I was going to pick a graded compound, or to generic green buffing compound if I was just going for utility. My first set dropped from 9u to generic green and it gave a highly polished edge.

You also won't need to go anywhere NEAR that coarse. A 120 suffices for me (Kalamazoo SM-1, fairly low-speed grinder) on all but the worst tip regrinds and bevels. When it gets really bad, I'll drop to a 80 or a 60, but that is extremely rare and tends to be used on mower blades instead of knives. Once you get used to the feel, coarser belts are very handy since they take the metal off with less heat build-up than a finer grit belt removing the same amount of metal. Having a few really coarse ones around can occasionally be a godsend, but don't expect to use them very often. :)
 
Ok thanks. I'm just used to bench stones and lansky stones and they don't seem to match the belts. Now I've just got ro get a motor and start having fun. Thanks
 
I have the Viel 1x42 and got mine from Viel with a motor. The only belts I've used to sharpen with it is a 320 grit about 2 or 3 times. I use a 600 grit and then jump to a leather belt with green compound on it. And that is it I'm done. I had a HF 1x30 before this Viel and have used a full range of belts with that one. I always suggest to order a single belt in many different grits your first time just to play around and find what you like. You will find that a belt finish is much different from a hand honed grit edge.
 
Ok. Thanks. Since you have the viel too how do you conrol belt tension. From what I can tell it just depends on how high the motor shaft is from the base. If its too low you'll have a lot of tension from the spring. Wouldn't too much tension be bad. Especially on the leather belt?
 
I haven't had to bother with that at all. It really isn't even that much tighter with the leather belt. Yes It will go on a little bit harder but there is alot of play in the spring for the top roller to self ajust.
 
Same on the Kalamazoo, the tension is just provided by a spring in the vertical shaft. I generally use the lock knob to slightly reduce the amount of tension in my leather belt when I put it on by locking the vertical shaft at slightly less than full pressure. Shouldn't matter all that much, though. The leather will stretch out to a certain point where it balances the spring pressure, then stop. Viel should be able to do it the same way. :)
 
Ok thanks. Still trying to track down a motor. Apparently mechanical/HVAC companies scrap everything they get instead of keeping the motors
 
Ok. Finally got a motor. 7 actually. Lol. First one I tried worked though. 1/4 hp. There's definitely a skill here as keeping angle constant is rather difficult. Especially working the right side of edge. I'm a lefty. So far though I've finally gotten a burr along both sides with the 180 grit belt. Now working my way through the finer ones
 
Ok thank you all for the help. I've finally found my sharpening way! I've now gotten my unsharpenable mora shaving and reproduced and a carbon chef knife the same. These belts do finish very fine. Finishing on 9 micron AO before leather. Wonder when the 15 micron Sic belt with wear smoother
 
Ok thank you all for the help. I've finally found my sharpening way! I've now gotten my unsharpenable mora shaving and reprofiled and a carbon chef knife the same. These belts do finish very fine. Finishing on 9 micron AO before leather. Wonder when the 15 micron Sic belt with wear smoother
 
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