Lets Talk About Joints - Lap Joints
THE LAP JOINT Like the scarf joint, the lap joint is used when joining the ends of two like-sized boards together.
This joint requires cutting the ends of two boards in the same fashion, and it's best to try to cut the depth of each 'lap' section by dividing the width dimension of the board in half, and cut each lap to that measurement.
The length of the lap joint cut may depend on a couple of factors.
It is best to give your-self some leeway here.
Try to allow yourself some extra length on each board, to avoid running out of material to make the joint.
If you leave yourself say, an extra few inches on each board, you'll still be able to correct a mistake if you make one.
A good length for the lap joint cut, is anywhere from 2 to 6 inches, depending on the size of the two boards.
If you're joining two pieces of 1 by 4 pine, for example, make the lap cuts about 3 inches long.
With a pair of 2 by 6's, you'd want to make the lap (length) cuts at least 4 or 5 inches long.
Now, you've made the lap cuts to length -what about the depth cuts? Take a look at the following example: if the two boards you need to join together are both 2 inches thick, you'll need to cut each lap to a depth of one half of that 2 inch thickness, which would be 1 inch.
If you cut too deep into one of the boards (by error), like say, 1 & 1/4 inches, you'll need to cut the other lap to just 3/4 of an inch.
So, in this case, the total depth of both lap cuts must not be greater than 2 inches.
The key to making tight-fitting lap joints is to make sure that the cuts you make are square.
To give optimum strength to a lap joint, use wood glue or construction adhesive, and counter-sunk screws.
If using glue only, it's best to clamp the joint fort the period time recommended by the glue manufacturer.
This joint requires cutting the ends of two boards in the same fashion, and it's best to try to cut the depth of each 'lap' section by dividing the width dimension of the board in half, and cut each lap to that measurement.
The length of the lap joint cut may depend on a couple of factors.
It is best to give your-self some leeway here.
Try to allow yourself some extra length on each board, to avoid running out of material to make the joint.
If you leave yourself say, an extra few inches on each board, you'll still be able to correct a mistake if you make one.
A good length for the lap joint cut, is anywhere from 2 to 6 inches, depending on the size of the two boards.
If you're joining two pieces of 1 by 4 pine, for example, make the lap cuts about 3 inches long.
With a pair of 2 by 6's, you'd want to make the lap (length) cuts at least 4 or 5 inches long.
Now, you've made the lap cuts to length -what about the depth cuts? Take a look at the following example: if the two boards you need to join together are both 2 inches thick, you'll need to cut each lap to a depth of one half of that 2 inch thickness, which would be 1 inch.
If you cut too deep into one of the boards (by error), like say, 1 & 1/4 inches, you'll need to cut the other lap to just 3/4 of an inch.
So, in this case, the total depth of both lap cuts must not be greater than 2 inches.
The key to making tight-fitting lap joints is to make sure that the cuts you make are square.
To give optimum strength to a lap joint, use wood glue or construction adhesive, and counter-sunk screws.
If using glue only, it's best to clamp the joint fort the period time recommended by the glue manufacturer.
