Commercial valve grinding compound comes in handy around the homestead even if you’re not rebuilding an engine. The abrasive powder is perfect for sharpening oddly shaped tools or putting the final finish on chisels or razors – it can even help you remove a stubborn screw.Automotive valve grinding compound is available at any auto parts store and it’s cheap. Less than five dollars for a tube that will last years – a little goes a long way. It’s made primarily from silicone carbide – though contains binders and lubricants to make it into a paste. The tough silicone carbide molecules form the equivalent of 120, 150, 180 and 220 grit sandpaper. This gradient of grit makes it versatile for polishing or sharpening metal.Since the blades of a push mower are curved in a spiral, sharpening them with a traditional whetstone is impossible – and likely to destroy the blades. Instead:
coat the blades with grinding compound and use a power drill to spin the mower for about a minute. Then recoat the blades and spin the blades in the other direction. Repeat until the blades are sharpened to your standards – three or four repetitions will bring the blades to a mirror finish.
If you use a tried and true leather strop to put the final edge on your knives and straight razors, take a new strop and coat it with mink oil. Give it three or four hours to soak into the leather, then coat the strop with grinding compound and a few drops of regular dishwashing soap to bind the compound to the strop. It’ll get your edges scary sharp in no time.
A tube of valve grinding compound in your toolbox is a quick method to loosen slightly rounded screws or nuts (before getting into the more aggressive techniques). Squirt a little bit of the compound into the head of the screw or the side of the bolt – the silicone carbide will add more “grip” between the head and the screwdriver and may give you the edge to start the fastener turning.