Arc Accessories FAQs
Straight answers to the questions people ask most about chipping hammers, wire brushes and electrode canisters.
Why do I need to remove slag between weld runs?
Stick electrodes leave a layer of slag over the weld that protects the weld metal while it cools. If the next run is laid over slag that was not removed, the slag can become trapped in the weld as a defect known as slag inclusion, which weakens it.
Chip the slag off, then wire brush the weld clean before the next run and before inspection. Pay attention to the toes of the weld and the edges of the joint, where slag tends to hide. Always wear eye protection when chipping.
How do I choose a chipping hammer?
Most chipping hammers have a pointed end for cracking slag and a chisel end for lifting it, so you can reach corners and flat areas. Choose one that feels balanced and comfortable in your hand for a full day.
Handles can be wood, tubular steel or spring steel. A spring handle absorbs some of the shock, which reduces fatigue, while a plain handle is simpler and tough. Wood handles are comfortable but can wear or work loose. The head should be hard enough to chip slag but not so hard that it chips itself.
Can I use one wire brush on mild steel and on stainless steel?
It is best not to. A brush that has been used on mild steel leaves tiny particles of carbon steel on stainless steel, which can rust and spoil the corrosion resistance of the surface.
Keep a brush for stainless steel only, and mark it so it does not get mixed up. The same applies to aluminium: use a clean brush kept for that metal. Clean the work and the brush, and keep stainless tools away from carbon steel workshop dust.
How do I get slag out of a narrow groove or corner?
Use the pointed end of the hammer to crack the slag, then work along the groove with a gentle tapping motion rather than heavy blows. Slag often lifts in strips once it is cracked. A narrow wire brush or a small scraper can clean what is left.
Where slag is stubborn, check whether your technique or the electrode type is making it cling. A slightly wider weld bead and the right arc length leave slag that is easier to remove, and cleaning each run before the next stops the problem building up.