Making your own canvas stretchers is a cheap alternative to buying them. Building your own will cost you about a third of the price. You will need the following materials:
1 standard 2x4
4 corner clamps
4 wooden clamp blocks
heavy duty staple gun
You will also need access to a woodshop and a good attitude!
Step 1: Take Your Measurements
Before starting any cutting, measure out the desired length for the dimensions of the canvas. Make a mark where you will cut the wood with the minor saw.
Step 2: Make Your Lenth Cut
After you have measured your lengths, use the mitre saw to cut the wood to the desired size. You will only need to measure twice, as the two vertical stretchers, and the two horizontal will be the same length (you will have two pairs of exact same lengths). Make sure to bring down the saw and spot where it hits the wood before turning it on. This will assure an accurate cut.
Step 3: Bevel Cut Your Length Pieces
You should now have two pieces of wood at the desired lengths of your stretchers. It is now time to bevel cut them in half vertically. This will assure a tight, suspended canvas over your bars. Adjust the bandsaw to 15 degrees clockwise and align the blade so it is in the middle of the width of the wood piece.
Use the push bars for the last few inches of the cut to avoid proximity with the blade.
Step 4: Bevel Your Corners
Go back to the mitre saw and adjust the angle to 45 degrees. These will be the corners of your canvas. You will turn the blade clockwise if you are feeding the wood from the right; counter clockwise if you are feeding from the left. Ideally, you will cut the right side of all the lengths first before rotating the blade and cutting all the left sides. Make sure the bevel on each of the four pieces is facing upwards with the shorter side closest to you.
You will have two pairs of the four lengths of wood. To ensure the pairs are the exact same length, clamp a wood block where one length of each pair ends, and use it as a mark for the second piece of the pair. This is a lot easier than measuring four times!
Step 5: Assemble Your Stretchers
You now have your wood cut down to the required size and shape. The hard part is over, congrats! You will need your clamp blocks, corner clamps, wood glue, and paintbrush.
Place the clamps on top of their blocks in each of the four corners. Place your stretchers in the clamps but do not tighten them. Using the paintbrush, apply a thin coat of glue on all the ends that will be clamped together. Tighten the four clamps assuring that the corners are flush to one another.
Step 6: Staple Your Stretchers
Without loosening the clamps, insert four staples on each corner. It is not necessary to wait for the glue to dry to begin this step. The staples should be about a half inch apart and a half inch from the edge.
Step 7: Drying & Clean Up
Once all sides are fastened, allow about ten minutes for them to dry. In the meantime, sweep up the sawdust around your workspace. You now have your own custom-made stretchers - happy painting!