How to make a DIY Mitre Box with offcuts of wood
Updated: Mar 4
Get those perfect mitre cuts without spending... well anything actually
Mitre saws are great for making angled cuts of wood for your DIY projects but they are often prohibitively expensive for the occasional DIYer, making mitre boxes or blocks a favoured go-to. The problem with some of the inexpensive plastic mitre boxes sold by hardware stores is that they are flimsy and can be shredded by a stray saw blade. They are also quite short, meaning that aren't good for cutting taller pieces of wood ie skirting boards.
Don't panic though, it's a quick and easy job to make your own and the best bit is you can use leftovers and save yourself some money in the process.
You will need
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- Offcuts of wood.
- Saw *
- Screws
- Wood glue (optional but handy if you have some)
- Pencil
- Clamps *or workbench (ideal but not essential)
1. Find the perfect offcuts for a DIY mitre box
The pieces of wood that you choose for your DIY mitre box will depend on the type of work you need a mitre box to do. I have a penchant for tall skirting boards so need a mitre box to be at least 17cm high to allow for the lip at the base of the box (more on that in a minute), but 12cm might be sufficient if you only ever cut shorter pieces.
2. Cut to size
Once you've found your perfect offcuts (Hardwoods are best but the idea is to use whatever you have available.) cut the length down to size, 30cm is about right, but go with whatever you think. You need at least two offcuts to create a functional mitre box, one for a side and one for the base, but you can add a second side to the box with a third offcut if you have one.
3. Join the offcuts
I used screws to join my offcuts for my DIY mitre box, but you could cut and glue or even use nails if they are all you have available. Top Tip: On one side, leave a lip at the base of the mitre box if you have a vice clamp or workbench as this will allow you to secure the mitre box when in use. If you don't have a way to clamp the base of the mitre box when it's finished, don't worry as you can screw it down to another longer offcut instead.
4. Mark and measure the cuts
To mark the cuts for the DIY mitre box, use a utility knife (if you have one if not just use a pencil) and a set square. Mark the two 45-degree angles and the 90-degree angle along the top of the side piece of wood. You can use a spirit level to draw a straight guide down from the initial cut.
5. Cut the marks for the DIY mitre box
Using a saw, cut down the side of the mitre box following the guides you made with the utility knife or pencil. Take care not to apply overly firm pressure as this can result in a wonky cut! Top Tip: Using a steel-backed saw will make your life easier and the cut more accurate. Although
my steel-backed saw is quite short and the steel part at the top is quite wide, so I had to finish the lower part of the cut with a different saw that would fit in the gap!
5. Add screw holes
If you don't have a vice or clamps, then you could drill two holes in the base of the DIY mitre box to be able to screw it down when in use. This obviously only applies if you have a workbench or large piece of wood that you don't mind screw holes in!
6. Test your DIY mitre box
Don't forget to test that it actually works! I'd recommend doing an internal and external corner as a trial as this will check that the 45-degree cuts line up.
Where next?
Here are some woodworking-related posts you might enjoy…
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