Paint, powder coating, rust, grease, and other surface contaminants should be removed from areas that will be welded. Clean bare metal produces more reliable welds and reduces the chance of contaminants being heated or vaporized during welding.
Sandblasting Cabinet
A sandblasting cabinet uses compressed air and abrasive media to remove paint, rust, and other coatings from metal.
Sandblasting is especially useful for:
- Irregular shapes
- Corners and joints
- Curved bicycle tubing
- Areas that are difficult to reach with other tools
Sandblasting can be relatively slow, so it is often best for smaller areas or detailed cleaning rather than stripping an entire large object.
Angle Grinder with Strip Disc
An angle grinder fitted with a strip disc can remove paint and coatings quickly from steel.
Strip discs are useful for:
- Larger flat or curved surfaces
- Removing multiple layers of paint
- Quickly exposing clean metal around areas that will be welded
Angle grinders are noisy and can create significant dust and debris. Always use appropriate eye, hearing, and respiratory protection and use dust extraction or ventilation when available.
Avoid excessive grinding, especially on thin-walled tubing. Remove the coating without unnecessarily removing or thinning the underlying steel.
Preparing an Area for Welding
You generally do not need to remove all of the paint from an entire object before fabrication.
Instead:
- Identify where cuts and welds will be made.
- Remove coatings from the immediate weld area.
- Expose clean bare metal on all pieces being joined.
- Clean away remaining dust or contamination before welding.
Leave enough clean metal around the joint so paint and other coatings are not directly heated by the welding arc.