Sharpening Chisels

Today as part of our practical learning in the carpentry workshop we learnt how to sharpen chisels on the stationary electric grinder, which had a dry grinding wheel. Sharpening the chisels made a significant impact on how well the chisels cut and the final finish on the joins.

1. First of all a blunt chisel, which is easily identified by the difficulty to cut or shave the wood, is taken to the grinding wheel.
2. When using the grind wheel it is important to wear safety glasses and/or have the perspex protective visor, that is attached to the grinder, placed inbetween the operators eyes and the grinding of the chisel. This is to avoid damage to the eyes because of small flying metal sparks.
3. The chisel is then observed to check for any chips taken out of the end of the chisel or if the chisels end is not square.
4.If this is so, the chisel is slowly pushed up to the grinding wheel with the edge of the chisel parallel to the grinding surface and ground until the end is square and/or all chips are removed from the edge.
5. Once this is done, the chisel is then turned upside down by simply turning the chisel as you would a screw driver, 180 degrees. The chisel should then be flat all the way up to the edge with the angle on the bottom.
6. The chisel is then slowly pushed towards the grinding wheel with the angled surface completely in touch with the grinding wheel. This grinds the angled surface down blade edge becomes sharper.
7. As you grind the chisel, move it side to side twice and then place in the water to cool the metal off and avoid burning, which is visible by the metal turning blue.
8. Once the chisel is satisfactorily ground down and the edge sharp, the chisel is then ground down on an oil stone with the flat surface being ground first. After it is smooth, then the angled edge is ground with particular care taken to keep the angle the same.
9. When the flat surface edge begins to bur outwards, you then repeat the first step of grinding the flat surface down until smooth.
10. Always keep the flat side of the chisel perfectly flat.