5.6.2 Planing of wood
Sanding is a mechanical surface treatment method for removing the uppermost layers of the substrate and exposing the actual base substrate.
Sanding is suitable for wood.
- It is not necessary to clean and degrease the surface
- Manually with an abrasive block or using sanding machines
- Grain size from K 120 to 180 is best for adhesive bonding applications
- After sanding remove all dust, etc. from the surface
Points to heed:
- Regularly change the abrasive paper
- Ensure the surface has a uniform finish
- Remove all residues and dust from the surface after sanding
- When sanding using machines, the wood can become too hot and can burn
- Risk of residues of the abrasive material in the substrate
- Abrasive materials can sometimes introduce iron ions into the wood. When bonding with dispersion adhesives this can lead to a blue coloration (when bonding oak, chestnut and walnut (tannic acid containing woods)).
- For extract-rich woods, sanding causes the extracts (oils, resins, minerals) to accumulate on the wood surface. It is possible that this can adversely affect the bonding properties.
- The time between sanding and bonding should be short. Long interim storage can result in extracts migrating to the surface, negatively affecting the subsequent bonding process.