Sharpening a Spade With an Angle Grinder
How to Sharpen a Spade
Sharp tools make life easier because less effort is required to use them. While sharp tools are dangerous if you don't take care, blunt tools can also be dangerous as you tend to apply more force when using them, possibly leading to an accident if the tool slips. This short hub shows you how to sharpen your garden spade with an angle grinder. A sharp spade makes it much easier to dig, slice the sod off the top of a lawn, edge flower beds, cut through roots when digging and slice through the top growth of weeds.
Can a Sharpening Stone Be Used to Put an Edge on a Spade?
For sure, but an angle grinder is quicker. Normally a sharpening stone or file is used to sharpen tools which require a fine edge e.g. a hedge trimmer/shears or knife. While you can use a sharpening stone or file to sharpen a spade, it takes more time, especially since the edge on a spade can become quite blunt and rounded after a season's digging, chopping roots, etc. The edge on a spade doesn't need to be quite so sharp as that on a knife and an angle grinder is perfectly adequate for the job. The only thing you need to do is take care and avoid overheating the edge of the tool, which can cause the steel to lose its temper or hardness (this is where the expression comes from)
Step 1: Hold the Tool Securely
You can use a vise, rest it on a block on the ground, on a stool or whatever. I'm using a log in the video.
Don't Forget to Wear Eye Protection!
Only use a grinding disk. Cutting disks are thinner and may shatter if you subject them to excessive side pressure.
Step 2: Start Up the Grinder
A grinding disk can usually be recognized because it is quite thick, nearly 1/4 inch.
Since this is only going to take less than a minute, you don't need all the normal safety clothing used when working with a grinder such as hearing protection or a dust mask. Eye protection is always essential though, because of the danger of disk fragments, sparks or splinters of metal hitting you in the eyes. Make sure you don't have any loose clothing which can get caught in the disk. See this hub for safety guidelines when using an angle grinder:
Switch on the grinder, if it has adjustable speed, use a slow speed setting. Now use a series of sweeps across the blade to sharpen it. The angle between the plane of the disk and the plane of the blade should be about 30 degrees. Keep the grinder moving, use light pressure and don't allow the disk to rest at any one point as this will overheat the steel and cause it to lose its temper. If tempering colors appear on the edge, typically blue, yellow and orange (caused by oxidation of surface layers), you're applying too much pressure.
Sharpening a Spade With an Angle Grinder
Can a Bench Grinder Be Used?
Yes it can. However personally I find an angle grinder more convenient. Also disks for angle grinders are much cheaper to replace when they wear than grinding wheels for bench grinders.
What Other Garden Tools Can be Sharpened This Way?
A hoe will also benefit from a sharpening, allowing you to slice through the roots of weeds. You can also remove any nicks or dents from the blade of an axe by grinding. Use the same technique as when sharpening a spade, but sharpen both sides of the edge. You can grind a lawn mower blade to remove dents caused by stones before using a sharpening stone to make it razor sharp. Don't remove too much material because it will unbalance the blade. Take a look at Lawn Mower Blade Sharpening for the Homeowner.
Most other home and garden tools such as knives, scissors, hedge shears and chisels which require a finer edge should be sharpened with a sharpening stone. Diamond sharpeners are also available. These are flat plastic and metal plates coated with powdered diamonds. They are quite good but the coating does eventually wear away.
Safety Shoes Aren't Just for Construction Workers!
If you're working in the garden, it's a good idea to wear safety shoes or boots. These have a steel toe cap and insert in the sole which helps to protect your feet from glass, metal, nails or other hidden nasty stuff when working in an overgrown area.