Shovels

The glory of gardening: hands in the dirt, head in the sun, heart with nature. To nurture a garden is to feed not just the body, but the soul.

Alfred Austin

This guidance also covers Gardening Trowels, Post Hole Diggers, & Spades.

Sharpening the outside (bottom) edge will push the shovel's blade towards the inside of the hole, and away from the outside edge. This helps to keep the hole from getting too big.

Also, this approach is easier as a flat file can be used for the sharpening activity.

A 6" smooth cut machinist’s hand file is useful to carry in your gardening tools box. Use it to resharpen the shovel as needed throughout the tool's usage for the day.

General Guidelines
Type α Notes
Gardening Trowels 45°

Gardening Trowels are usually made by stamping a piece of metal, leaving an α angle of 90°. As this tool is often used in soil which is already loosened, a sharper angle is not typically necessary. But if desired, 45° is recommended.

When used for weeding in hard, clean dirt 30°

When weeding in hard dirt, a sharp angle can make piercing the surface much easier. But, a sharp angle like this will dull much easier, especially if the tool encounters rocks in the soil.

Post Hole Diggers 45°

The user should consider sharpening this tool in the inside of the curve. That is a bit harder; however it will help push the two blades apart when pushed into the hard soil.

Sharpening the inside of the curved edge will require a half round or round file.

Shovels 45°

If the soil is very rocky, then a more obtuse angle like 60° or even 90° may be needed. Just be aware that these will take more work to use.

Spades 45°

As with shovels, consider the soil in which the tool will be used. But a 45° angle is a good compromise.

Notes & Comments

Information regarding Grindstones

These tools are typically stamped ouf of metals which are not terribly hard. Consider this when selecting sharpening tools: if too much heat is generated in the sharpening activity, this can easily remove whatever temper was added to the metal.

Shaping the edge: New shovels I have purchased have an angle (α) of 90°. Therefore, initial shaping of the edge is to be expected.

A machinist’s hand file such as a 12-14" bastard file is often sufficient for this task.

If you use an angle grinder, consider using a 120 grit flap disc. A metal grinding wheel may be needed for large-scale shaping. In either case, be sure to not overheat the metal too much: it weakens the metal.

Sharpening the edge: Use a machinist’s hand file.

  1. Start with a 8-10" medium (or second) cut file.
  2. Finish with a 6" smooth cut file, then use this file to remove the burr.

Ongoing Maintenance

Be sure to remove all caked-on dirt. A wire brush or putty knife can be useful for this. A well-kept tool will last your lifetime, and will still be usable by your children (and maybe your grandkids).


Camellia Oil Spray Bottle

Sap can be removed using a solvent. Acetone works well, but be sure to wear protective clothing as this is not kind to your body, and be sure the area is well ventilated.

After using any solvent, be sure to apply a thin coat of camellia oil to the tool. I like the spray bottle of camellia oil sold by Tools for Working Wood.

Some advocate using boiled linseed oil (BLO), but BLO often has heavy metals or other bad chemicals added for drying agents, and these are not good for you to handle, nor would they be good for the plants on which you might use this tool.

If the tool was exposed to any diseased plants or soil which is infected with pests, give it a quick wash in diluted bleach (1 part bleach to 8 parts water), and then rinse with plain water. Be sure to dry afterwards, and apply a thin coat of camellia oil.

Tools in Storage

Gardening tools often get stored for a while after sharpening, so it is recommended to oil the sharpened surface with camellia oil. (Indeed, all unpainted surfaces would benefit from this.)

Petroleum jelly is another option.

More Information

Books & Papers

About this site
Remember : The goal of sharpening is to produce sharp tools, and these tools can injure you if mishandled. Safety measures should be followed to protect yourself and those in your shop. Be sure to read and follow all instructions from the manufacturer, and and utilize proper safety equipment. Never consume alcohol or anything that could impair your judgement before sharpening tools, or using sharp tools. Comments can be sent via eMail to me at SharpeningHandbook@Gmail.com.