Crawls Backward (When Alarmed)

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Boston KS Pencil Sharpener Restoration, Pt. 1

You may recall a few posts back I commented on the non-quality of my Home Despot pencil sharpener. Sure, it's really meant to sharpen carpenter pencils, so I suppose I can excuse its performance on regular pencils. But I'd really like a decent sharpener for the workbench.

I have a Panasonic electric sharpener, but even that falls short for me. I grew up using manual sharpeners and, when I learned drafting, I used rotary pencil pointers. I don't think those manual devices can be topped.

So I solved the problem. I bought a few classic pencil sharpeners. They actually came together in one bunch, so I have some to play with.

This one is the first out of the box. It's a Boston KS. Pretty basic; those of you about my age may recall something similar in your schoolrooms. This one is probably from the 1970s I would guess - the stamp on the bottom says it was made in Statesville, North Carolina. I'm reasonably sure the older ones were made in....Boston.

Like most of the older junk I accumulate, this sharpener needs some attention. It's a bit tarnished, and it's hard to turn. You can't actually sharpen a pencil with it, which presents a problem!

With the cover/shavings collector thing removed, we can see the innards. Does this bring back memories, or what?

You can see how clogged up the blades are. I'm sure that's why it's not working. So let's fix it!

We unscrew the two rods that the blades rotate on. These probably have an actual technical name, like "blade rotator shaft."

They unscrew easily.

And they easily slide out of the blade carrier/cage/chassis.

You can see the simple brilliance of this design. It's a set of planetary gears that the crank turns, which are part of the blades. So turning the crank directly turns the blades. Not much to go wrong with it.

One of the blades dropped right out, and other remained in place. Since I want to get them both out so I can sharpen them (crazy, I know!), I needed to remove the whole blade chassis.

The handle simply unscrews from the center rod which runs though the chassis/blade frame. I just put it in a vise and removed the crank.

The handle comes right off - note the threads. That's the end of the chassis/cage that holds the blades.
Here's one of the blades. You can see how it's packed with some foreign material. I'm not sure what it is, but it might be crayon!

Here's the pencil sharpener disassembled. Very simple but efficient design. Note the gears that are part of of the blades. They appear to have been cast in one piece.
With the sharpener dismantled, I hit all the parts with PB Blaster degreaser. A lot of crud came off easily.

But there was still a lot of mess deep inside the grooves of the blades and in a couple of crevices in the blade and main shafts.

I also wanted to clean the degreaser off the parts as well. So I soaked those parts in a jar with some naptha for a few hours.

You can see the color of the naptha at the bottom of the jar - it turned grey and had black particles in it. I wound up flushing the parts with naptha three times until the naptha stopped changing color.

Even after that, I still had to use q-tips and toothpicks to get the remaining crud out of the blades.

This is that main shaft end of the blade cage. You can see there was still caked-on old lubricant after the degreasing and naptha bath. I took toothpicks and an x-acto knife to scrape this clean.

Then I used #0000 steel wool to get the last remants of grease off, as well as clean up the rotating shaft.

Here we have the newly cleaned parts ready to go.

Next time - sharpening the blades and reassembly of the sharpener!


Post a Comment 2 comments:

  • Neil Richard said...
    November 2, 2017 at 8:11 AM
    Just wanted to stop by and say thank you for such a great tutorial on restoring one of these classic pencil sharpeners. I bought an old one at a neighbor's yard sale for a dollar and with your help, I was able to restore it to working condition (although I skipped the sharpening part). Now I feel like I can tackle the other one in the house with ease. Thanks again!
  • Yr Fthfl Blggr said...
    November 4, 2017 at 10:11 AM
    Thanks for the kind words. It's fun to get something like this going again, isn't it. Such a clever design, and with a little service, it can work forever.

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