Diamond plate or water stone: a first sharpening setup, from what I read

A new chisel needs an edge before it is any use. I have not put one on yet. This note is about what you sharpen on, not how you hold the blade. The how is in my sharpening note.

Diamond plate or water stone: the short answer

A diamond plate is a steel plate with diamond grit bonded to its face. It stays flat, needs little upkeep, and cuts faster than other abrasives of the same grit.¹

A water stone is a synthetic stone made to wear away as you use it. That keeps it cutting, and it is also why you have to flatten it.² Water stones go finer. A fine water stone leaves a shallower scratch than a diamond plate with the same number.³

So, for a beginner with a few chisels: a diamond plate is less to look after. Water stones give a finer polish, if you will also keep them flat. The shop blog I read does both: diamond to shape and sharpen, then an 8000 water stone to finish.⁴

What the experts say

Medium. Three Fine Woodworking authors, three different years. They agree on upkeep. They do not agree on the finish.

Brian Boggs prefers diamond. He says it cuts fast and needs almost no maintenance, and that his plate stayed flat for five years. It costs more up front. His argument is that faster sharpening pays that back. He also says diamond handles every steel well, including A2 and carbide, where softer abrasives like water stones do worse.⁵

David Charlesworth prefers water stones. He keeps his 800 and 1200 stones sitting in shallow water. Stones of 4000 and finer stay dry and get sprayed before use. A coarse stone stored dry wants about five minutes in water. He warns that the stones are built to erode, so a beginner can hollow one fast. In a shop that freezes, do not leave them in water: they can crack. His starter set is 800, 1200 and 6000 plus a nagura stone. He says an 8000 water stone polishes much better than Arkansas, ceramic or diamond.⁶

Deneb Puchalski flattens water stones on a coarse diamond plate bigger than the stone. He uses 120 micron, which he puts near P120 paper. His warning: diamond plates wear out sooner than many people expect. Keep one plate only for flattening, because sharpening blades wears small spots into it.⁷

Oil stones and sandpaper, briefly

Richard Maguire prefers oil stones. They suit quick touch-ups and a shop with no fixed sharpening station. He says they are too slow on thick, hard irons, which is where diamond wins.⁸

Tools for Working Wood says oil stones stay flat for years but cut slowly. They name an India stone for coarse work and a hard Arkansas for the fine edge. Sandpaper on a flat backing is the cheap start. Their catch: the finest paper is hard to find, and film or paper you keep replacing ends up costing more than stones.⁹

What owners report

Maguire writes as a working woodworker, not a lab. He finds water stones soft and messy, cold to use in an unheated shop, and in need of constant care. Flattening breaks his rhythm. He bought diamond plates, likes that they need no soaking or flattening, and still found them nothing special. He plans to go back to oil.¹⁰

Readers under Charlesworth’s article name King and Sigma stones and argue water against diamond. A reader under the shop post says technique matters more than an expensive system and suggests a combination India stone. I am treating comments as comments.

Where they disagree

The finish. Charlesworth and the shop blog both put a fine water stone ahead of diamond for polish. Boggs puts diamond ahead for hard modern steels. I cannot settle that without an edge to look at, and I have none.

How long a plate lasts. Boggs had five flat years. Puchalski says plates wear sooner than people think. They may be talking about different use: Puchalski’s point is about one plate doing both flattening and sharpening.

The grit jump. The shop blog names a Norton 1000/8000 stone as the budget water stone, and in the same post calls 1000 straight to 8000 a big jump that slows the finish. Both sentences are on one page.

My sharpening note leans on Paul Sellers, who uses diamond plates. His pages would not load for me this time, so he is not a source here.

My take

If I bought today, for chisels only, I would start with one diamond plate. Nothing in these sources says it needs soaking or flattening, and a coarse one can flatten a water stone later. I would add a fine water stone when I want the polish two sources describe. If I did buy water stones, I would keep a plate just for flattening, as Puchalski says. And if my shop froze, I would not leave them in water.

No prices here on purpose. Boggs only says diamond costs more up front. Which chisels to sharpen is the chisel set guide. The photo shows chisels. It is not a stone.