Curtis Clamp - 90 degrees

The Curtis Clamp is a 3D‑printed guide for DMT diamond honing tools that makes sharpening iceboat runners faster, safer, and more repeatable—without sacrificing accuracy.

Each Curtis Clamp includes a fitted rebate that securely seats DMT 111 mm diamond honing tools. It prevents the tool from shifting during use, so you get consistent results without over-tightening the clamp’s set screws.

The DMT 111mm diamond stones are not included and can be found here

Why it matters

Iceboat runners are made from very hard steel. Many top racers run 440C stainless, heat-treated to roughly 59 Rockwell. Belt sanders are great for establishing runner geometry—rocker profile and cutting-edge angle (90°, 95°, or 100°)—but they’re not the right tool for routine maintenance. 

For day-to-day upkeep, hand sharpening is the standard. 

Four angle options 

The Curtis Clamp comes in four models, each set to a specific angle and embossed so you don’t mix them up:

• 90°
• 95°
• 100°
• 77°

Why different angles?

Changing edge angle is one of the main ways racers tune for conditions. As a general rule:

• 90° for high wind and hard ice
• 95° sits in between
• 100° for softer ice and lighter wind
• 77° supports advanced tuning for a compound edge - upper section, which only occasionally makes contact, is sharpened to 77° to minimize frontal area and reduce drag. The lower, ice-contacting edge remains sharpened to 90°,95° or 100°