Sharpening stones are expensive. They’re also usually very small. Here’s how I made a very effective, large sharpening stone for less than $10.

Start with a large, flat stone

I bought this 12″ x 12″ granite tile at my local home center. It was a couple of dollars.

I added four drops of leftover silicone caulk to the underside corners. This added grip to the tile when I used it on my workbench.

Add water and sheets of sandpaper

I bought a value pack of automotive sandpaper in sheet form for about $5. I mist the top with a water spray bottle and rub the water into the surface with my finger. It takes a few minutes for the water to soak in. Then lay the sheets of sandpaper on the wet surface and press them flat. Then will cling to the flat granite stone and stay in place. (For these photos I didn’t wet the stone and stick the paper down).

I use three increasingly fine grits of sandpaper for chisels and tools I haven’t sharpened before. If I have sharpened the tool before, I start with 800 grit, then 1200, 1800, 2500, etc. I think the grits in the pack I bought go up to 3000. I usually don’t go any higher than 1800. My edges are super sharp after 1800. 2500 is a bit excessive for me but some people want a mirror finish.

Use a Sharpening/Honing Guide

In order to get a consistent angle in the chisels and hand plane blades, I like to use a sharpening guide. I found this one at my local hardware store for $12.99.

When you tighten the screw, the guide holds the blade tight while you sharpen it.

There you have it. This extremely flat sharpening stone will give you extremely sharp tool blades. And remember, a sharper blade is a safer blade.