5: Spijk Selby on Hacking Gently (knife sharpening)

## Overview Spijk Selby, an American-raised blacksmith who apprenticed at Hancock Shaker Village for four years and founded her own forge business in 2017, presents a comprehensive guide to understanding and sharpening knives. Despite the title referencing "hacking gently," this talk focuses entirely on practical knife sharpening and metallurgy.

## Key Topics Selby begins with the history and chemistry of steel, explaining how iron gains hardness through carbon content and how different alloying elements affect performance. She details the language and anatomy of knives—tang, bolster, heel, spine, edge, and tip—focusing primarily on edge geometry and tip design.

Temper colors are central to understanding steel quality. As temperature increases during the forging process, color progression indicates changes in hardness and flexibility. Blues at the higher end of the spectrum produce soft, flexible steel (ideal for fencing swords), while colors around 350-440 degrees mark typical chef's knife ranges. Japanese knives differ from Western knives: Japanese blades feature convex edges suited for delicate cuts on soft foods like fish and vegetables (around 7-degree angles), while Western knives have wider convex edge geometries designed for cutting through bone and flesh.

## Technical Details Sharpening methods discussed include traditional whetstones (Japanese and Chinese), sandpaper on flat surfaces, powered engine-driven stones, and specialized devices like the Wicked Edge. A critical warning: powered stones can overheat blades and inadvertently re-temper them, causing damage.

Grit progression matters significantly. Lower grits (50-500) remove more metal per stroke and suit knives with chips; standard grits start around 500. Fine finishing occurs at 1000-8000 grits. Sandpaper offers an affordable entry point, available at hardware stores up to 1500 grit, with emery cloth lasting longer at slightly higher cost. Japanese whetstones, purchased from sources like Korin, are described as "the best" and reasonably priced (approximately $50).

Selby emphasizes matching existing blade angles before adjusting geometry. For kitchen knives, she personally prefers slimmer edge geometries (around 7 degrees), contrasting sharply with Wüsthof's standard 35-degree angles. Edge angle directly affects edge retention—different steel types and tempering methods dramatically influence lifespan. She mentions contemporary air-hardening alloys that become impossibly hard to sharpen but offer extreme edge retention.

## Maintenance Critical maintenance rules include: keep knives dry and never soak handles (they can crack); never use dishwashers (which completely ruins edges); hand wash only. Carbon steel knives rust quickly—even 30 seconds of wetness can cause visible corrosion. Tung oil (available on Amazon for ~$6 per bottle) works excellently for finishing handles and is food-safe. Her personal practice involves sanding handles to 2000 grit before oil application.

## Takeaways Sharpening is achievable without expensive tools or machines. A $2 thrift-store knife can become a quality cutting tool through proper technique. Understanding the specific purpose of your knife—what you're cutting and desired performance—determines ideal edge geometry. Traditional sharpening methods require more time (often 6 hours versus machine seconds) but yield customized edges and eliminate overheating risks. The speaker recommends beginners start with one 1000-grit stone for approximately $50, which suffices for most kitchen applications.