How to Use a Mortise Chisel

In this video you will learn how to use a Mortise Chisel.

A Mortise chisel is built to withstand mallet blows and lever out waste without breaking.

The thickness and width of the blade keeps it well aligned to a good depth.

As the name suggests, these chisels are perfect for chopping out mortises – particularly deep mortises in dense wood.

The tools that you will need are a Pencil, a Try Square, a Marking Knife, a Mortise Gauge, a Vice, a piece of wood, a Mallet and a Mortise Chisel.

The Mortise Chisel has a reinforced handle that holds a stout steel blade with flat sides.

The 30 degree bevel ‘knee’ forms a fulcrum that is useful for leveraging out waste wood from mortises.

A steel hoop and a ferrule at the top and bottom ends of the handle, prevent the wood from splitting when struck.

Before you start chiseling, ensure that the layout is precise.

Use a marking knife along the sides of the tenon piece to mark the length of the mortise.

Highlight the marks using a pencil and trysquare.

Set the scribes of the mortise gauge to the thickness of the Tenon which should also follow the thickness of the mortise chisel.

Center the scribes on the workpiece and mark the width of the mortise by running the two scribes between them.

Highlight the lines with a pencil.

Mark the desired depth of the mortise on the blade of the chisel for reference.

Now that the markings have been made, clamp the workpiece onto the Vice.

Clasp the handle of the Mortise Chisel using your secondary hand.

Wrap your thumb around its base, but clear of the steel hoop.

With your dominant hand, clasp the handle of the mallet, ready to strike the head of the Chisel.

Place the tip of the Mortise Chisel on the waste wood less than quarter of an inch away from the line marking one end of the mortise.

Hold the bevel away from the mortise walls as the cut tends to travel in the direction of the bevel.

Strike the chisel with the Mallet, creating a series of notches from end to end.

Do not lever the chisel against the edge.

Now, gently chisel out the layer of notches.

Repeat this process till you reach the desired depth.

Once you are close to the final dimensions of the mortise, smooth down the edges till you reach the layout lines.

Use a wider bench chisel to even out the longer edges of the mortise.

You have now learnt how to use a Mortise Chisel.