Gummy stones are essential tools in ski maintenance, primarily used for removing rust and smoothing out burrs on ski edges, offering a gentler touch compared to more aggressive tuning tools.
What is a Gummy Stone?
A gummy stone is a pliable, abrasive block, often made of silicon carbide or aluminum oxide, designed to gently remove material from ski edges. Its soft, rubbery texture allows it to conform slightly to the edge, making it ideal for delicate work.
Key Uses of a Gummy Stone on Skis
Gummy stones serve two main purposes in ski tuning:
1. Rust Removal
Rust can build up on ski edges, especially after storage or exposure to moisture. A gummy stone effectively cleans off this surface rust without significantly altering the edge's geometry.
How to Use for Rust Removal:
- Preparation: Ensure your skis are clean and dry.
- Application: Hold the gummy stone flat against the rusted area of the edge.
- Technique: Apply gentle, consistent pressure and rub the stone back and forth, parallel to the edge. The rust will gradually disappear as you work.
- Caution for Base Edges: While effective, use a gummy stone on your base edge sparingly. Base edges are easily affected by abrasion and generally shouldn't be "meddled with" extensively, as their angle is crucial for glide and turning performance. Focus primarily on the side edge for rust removal.
- Finishing: Wipe away any residue with a clean cloth.
2. Deburring and Detuning
Skiing can create burrs (small, sharp pieces of metal) on edges, which can feel "spiky" and hinder performance. A gummy stone is excellent for taking the spiky-ness off these burrs, making the edge smoother to the touch. It's also used for "detuning" the tip and tail edges, making them less aggressive and preventing them from "hooking" when initiating or finishing turns.
How to Use for Deburring/Detuning:
- Identify Burrs: Run your finger gently along the edge to locate any sharp or "spiky" areas.
- Targeted Smoothing: For burrs, hold the gummy stone flat against the burr and make a few light passes. The goal is to knock off the sharp points, not to remove the burr entirely.
- Tip and Tail Detuning: For the ski's tip and tail (typically the first 10-15 cm from each end), hold the gummy stone at a slight angle or flat against the edge and make light, sweeping motions to dull the sharp edge. This reduces catchiness.
- Limitation: It's important to note that while a gummy stone can take the spiky-ness off a particularly bad burr, a file and diamond stones will do the actual fixing and restoration of the edge's true sharpness and angle. A gummy stone is for initial clean-up or gentle maintenance.
Gummy Stone vs. Other Edge Tuning Tools
Understanding when to use a gummy stone in relation to other tools is crucial for proper ski maintenance.
| Tool Type | Primary Function | Best Use Case |
|---|---|---|
| Gummy Stone | Rust removal, gentle deburring, edge detuning (tip/tail) | Quick fixes, pre-filing prep, making edges less "grabby" |
| File | Reshaping edge geometry, removing large burrs | Major edge repair, establishing base and side edge angles |
| Diamond Stone | Polishing edges, sharpening, refining edge finish | Post-filing, fine-tuning edge sharpness, maintaining edge integrity |
General Tips for Using a Gummy Stone
- Cleanliness: Always start with clean skis. Dirt or debris can scratch the base or edges.
- Light Pressure: A gummy stone works best with light, consistent pressure. You're not trying to aggressively remove material.
- Wipe Down: After using, wipe the edges clean to remove any metal filings or residue from the stone.
- Complementary Tool: View the gummy stone as a complementary tool in your ski tuning kit, not a standalone solution for major edge work.
By incorporating a gummy stone into your ski maintenance routine, you can effectively manage rust and keep your edges smooth and functional between more intensive tuning sessions.
