Harbor Freight 1x30 Sander

A while ago I picked up a 1x30 Harbor Freight sander with two intended purposes; do some major thinning and cleanup on a real cheap Old Hickory butcher's knife and to try to put a mirror polish on my Kikuichi Inox Honyaki Gyuto. I managed to find some time to do the 2nd of those tasks.

Previously, I had used stones and sandpaper to get the grind marks off of the Gyuto using some pretty coarse stones, but I never managed to get my grind marks off. I was hoping that using the Harbor Freight belt sander I could speed things along. I had varying success.

First, for my setup, I got a Harbor Fright speed controller to go with the belt sander and I also bought a variety of MicroMesh MX belts ranging from 240 down to 800 grit. MicroMesh grits don't line up with stone grits; they are much finer than they sound. I think the belts all together cost more than the sander. As an experiment, I also tried using some cutting wax with the belts.

There's already some info out there about this belt sander, so here are some of my personal observations.
* The sander wouldn't start up unless the speed controller was at least 60%. After that I could turn it down if I wanted to.
* You need to wait until the sander sped up, and then only use very light pressure or the belt would slow to a stop. Light pressure at a fair speed was much more effective than any level of pressure that would slow the belt down.
* Cutting wax was very helpful at lower grits; maybe as high as MicroMesh MX 320. However, it also left a waxy film on the knife that is difficult to wash off. If you don't wash it off before going to the next grit, it will contaminate the next belt.
* I had a lot of trouble with control at the tip and the heel of the knife. At the heel, I found it very difficult to get the knife flat against the belt so I ended up with a taper at the last ~4 mm of the heel. I also ended up knocking a couple of mm off the tip that I later had to fix.

After I got though my finest MicroMesh MX belt (800 grit) I hand sanded with MicroMesh MX 1200. I also did some hand sanding with MicroMesh MX paper in between belts. The odd result was that although it has an amazing mirror polish, I can see small scratches that no matter what I tried, I couldn't remove. You can only see the scratches if you focus on the blade, not the reflection in the blade and they are way too fine to capture with a phone camera, but they are there and they bother me. It's just something that I'll have to live with, at least for a while.

Where it really counts is the knife performance, and in that respect I am very happy with what I achieved. Prior to this project I had a big problem with adhesion (form members have taken to incorrectly naming this phenomenon "stiction") as well as friction (drag). Potatoes would get glued to the side of the blade so hard that I would need considerable force to pry them off. Even with onions, the knife would get stuck like glue in the onion when I made horizontal slices. After this, the knife just fly's through onions. Potatoes still stick to the blade, but they can now can be shaken off with a flick. It's hard to expect better than that from a sub 2mm laser.

 

Thanks for the tip on using a speed controller. I've had one of these machines for awhile and tried using a router speed controller but it didn't work very well -I'm going to try your method and see how it goes.
Ben

 

the only speed controller I see at harbor freight is for a router, is that the one you used? How slow will it go? at low speed does grinding drag the grinder down? Have you used it for the thinning operation yet?

 

I have one but would never dream of sharpening or polishing on it. Its a squirrley little sander. You have more guts than me. Mine has been delagated to spine rounding.

Would love to see some pics. I have a few knives I want to attempt to mirror.

 

Yes, that's the one. It's rated for 15A. The sander is less than that, so I figured why not?
If you get the belt started you can turn it down as slow as you want. However, at low speed you can only use the very lightest of pressure or the belt will slow to a stop. The lower the speed the less pressure it takes to stop it.
I haven't tried to thin with it yet. I don't have a problem with most thinning on a coarse stone. I might pull this thing out again if I want to try to clean up my Old Hickory butcher's knife. I bought that thing for just a couple of bucks new and I couldn't see the back of it to find out that a third of the blade had no bevel at all. I ground a good enough bevel into it on my Atoma 140, cursing at it for the hours that it took, but one day I might get it to where I want it.

I had the thing for a few months before I screwed up the courage to just do it. It was like learning to sharpen all over again... it takes forever to get it right and just a couple of seconds to really mess things up. I'm still kicking myself over what I did near the heel.

The mirror is pretty scuffed up now. It's a tool. I use it. My wife uses it. It was never perfect to begin with. Some of the underlying scratches seem like they are pretty deep/coarse and I need to get them smoothed out if I'm going to get it right. I'm considering getting a King 800 to lay down a new base by hand and work my way up from there. My Bester 1200 doesn't make much progress against those deeper scratches and I'm pretty sure that my Beston 500 is what did the damage in the first place. At the moment I've got nothing in between.

If I remember, have the time, and can figure out how to do it, I'll post a pic or two. (don't hold your breath).

 

I'm pretty sure that a router speed controller isn't good for the type of motor found on the HF sander. Even if that's not the case I found it worse than useless when I tried this years ago. No power at any RPM/speed so I canned the idea. Do check on the motor type though, I think I recall someone (or two) frying their sander out from this.