Using a Belt Sander for Sharpening?

[Emily]

To date, I've been sharpening my tools by hand using sandpaper and a flat surface (inspired by the "scary sharp" method). This is no longer working for me as it takes me forever to get my tools sharp, and I can't even get them as sharp as I'd like. Plus, the repetitive movement is causing my shoulder tendinitis to act up.

I have 6 tools: a diamond parting tool, two spindle gauges (two sizes), a skew chisel, and a weird v-shaped tool.

My budget is very slim, so I'd like to use something I already have access to. Would a belt sander work? I did some googling, and this individual's set up seems reasonable to me. What do you guys think? I'm very new, so I'm looking for a more experienced opinion.

Also, what types of sanding belts would I need? Would I work up from 150 through to a finer grit similar to what I do by hand?

If it's a terrible idea, please let me know. And I'm open to any other suggestions!

 

[carlmorrell]

I have been using a belt sander exclusively for years. I tried other methods. Even for my normal woodworking chisels, I can make them shiny with stones, pastes, etc, but if I want them sharp, I use my tabletop beltsander.

The sander will get a gouge sharp enough for wood, and many acrylics. However, I just decided to try a carbide tip for some really hard tru-stone. I am a convert now. I will still use my trusty M3 fingernail gouge for most work, and will continue to eyeball it on my sander.

YMMV

 

[Emily]

That's reassuring! The hardest thing I've ever turned is Maple, and I've had no problems so far using what I have. But I figured a belt sander could only improve sharpness and save me some time.

 

[Mike Powell]

Yup, I use the disk side of my bench top belt sander.

 

[Emily]

By the way, would the tool edge go against the direction of the sander, or drag along behind? I feel like dragging behind would minimize risk of tearing the paper, but I may be wrong.

 

[Mike Powell]

if the rotation of the sander is counter clockwise, I lean my tool clockwise.

 

[monophoto]

Emily -

In Europe, it's common for turners to use a 'linisher' to sharpen tools - that's essentially a vertical belt sander. In fact, Robert Sorby sell one for their tools.

I've used an ordinary belt sander - that works, but it's a bit aggressive (and I'm not comfortable holding the sander upside down while trying to sharpen tools).

For me, a better solution was a sanding disc. I bought a 5" hook and loop sanding mandrel at Harbor Freight. I have a tap that matches the thread on my lathe spindle, so I mounted the mandrel on a block of wood that was drilled and tapped to allow me to mount it on the lathe. I use a standard 220 grit sanding disc, and lightly hold the tool against the disc (in the 6-9 o'clock position) with it spinning at a fairly low speed.. With gouges, I rotate the tool about its axis, while with parting tools and skews, I move the tool from side to side.

The inconvenience factor for me is that I have to take the work off the lathe to sharpen tools. An alternate arrangement that some people use is to make an oversized replacement handwheel, with sandpaper on the outside face.

 

[kovalcik]

Here is a good you tube on belt sander sharpening. (You can skip the first 5 minutes)

https://www.youtube.com/watch?v=aaqIGVmVHY8

It uses a benchtop model, but you can probably adapt it to a hand sander. The jig he uses for the gouges is easy to make. Hopefully this will give you a couple ideas.

 

[Jim Burr]

Several gigs are sold just for that purpose...may have some increased cost in belts, but if it works correctly...have at it!!

 

[KenV]

Emily -- welcome to the fun of turning!!!

The kind of abrasive makes a difference as does the speed of the abrasive going past the steel. I have had best success with the Norton blue belts and steel. The belt moving away from the edge is the least risk approach but requires a steady hold on the rest to avoid "dubbing the edge". There are a lot of opinions on grit size, and I suggest you try several to see what you are most comfortable with. 80 to 180 is the likely range, but some like a bit finer (220 or so. The belt speed will make a difference, and there is not a cross walk between grinder wheel grits and sanding belt grits for exactly the same effects.

Make yourself a few jigs to set the same angle over and over again. There will be changes between your skew and your gouges and you will get to using shear scraping at some point.

I hone edges as I go with a diamond hone and periodically head back to the heavy duty abrasives.

Sharp consistent edges make turning more fun -- and scary sharp (which I use for some edges) is a hard way to go for lathe tools.

 

[Wood Butcher]

Just a touch of paranoia for you; I have used my belt sander to sharpen and it worked really well. I also nearly set fire to the shop in the process. There was some sawdust still in the belt/disc sander and the sparks from "grinding" ignited the dust. It didn't just fire up, it smoldered for about an hour before I realized the shop smelled funny and I couldn't see for the smoke. If I had done that just before wrapping up for the day and returning to the recliner, well, it could have been bad.
BTW, be real careful of sucking up screws, nails, washers or anything that could send ferrous metal into the dust collector if said collector has a steel impeller, same thing can (will) happen.
WB

 

[Emily]

Thanks for the heads up! That's something I'll definitely watch out for.

 

[robutacion]

Emily,

If you could afford a carbide tipped tool, that would be a great suggestion to avoid the sharpening require on HSS tools.

There are many quality grades of the HSS steel and this is one of the reasons why identical tools from some brandes are so more expensive.

The one problem that people seem to forget is that, normal HSS tools are tempered only so far and the correct cutting edge angle starts changing as soon as the toll starts to be re-sharpen manually.

Sure, jigs help considerably to maintain the same angle but then, using incorrect grits and allowing the metal top "burn", are the most common reasons why tools stop accepting an edge properly.

The finer the grit, the more heat it will produce and not the ideal type grits to give the original angles and sharpen those tools edges. Sharpening tools is an art and therefore, is not only a matter of "shining" the cutting surface, some of the best sharpening techniques involve grinding and then honing.

Honing is simply the process of making the cutting edge smooth and not "serrated" as many coarse grits will do, this is also called fine tuning the cutting edge...!

So, you may find that, your tools cutting angles are no longer correct and even if you sharpen properly the cutting edge, you may have a hard time to make the tool work as intended so, inspecting those angles, are the first step you should take.

I certainly don't recommend everyone to attempt correcting the cutting angles of a tool, done incorrectly you can simple destroy the cutting capabilities of the steel/tool. You may know or have someone close to you that is experienced and could do that for you, then and only then you could keep the cutting edge sharp by using a simple wet stone or a diamond card fine sharpener.

Belt sanders can do the job but, are far from ideal, as the belt joint is not smooth and affects the results of making a straight surface edge, and can start a fire and mentioned above. I would prefer to use a disk sander with some 120 grit blue disc, and then hone it very quickly.

Like anything else we do, sometimes we only need to understand how things work and see someone do it, that works most of the time...!

Good luck,

Cheers
George