Tools needed: Block of wood, hammer, Philips head screwdriver.
Unpack your stretcher and inspect for any shipping damage.
Do NOT use glue on any of the joints. The joints are specially fabricated with a precision fit to be tight-fitting enough to give stability to the stretcher. This tight-fitting joint will give minimal movement while handling and stretching the canvas, but also allow movement with the included keys to tension the canvas in the future.
Put your stretcher parts on the floor in the proper arrangement for your stretcher. Make sure the bevels of the stretcher bars are facing in the same direction.
If you have two or more braces, start by assembling the lap joint in the center of the braces and affix with the included ¾” screws (4 screws per joint). Screws only need to be snug. Over-tightening could strip the screws.
Start with one corner of the stretcher and begin to slip the joint together. You only need to get the joint started at this time.
Next, move to the double mortise and tenon for the brace and get it started.
Slowly move around the stretcher getting all of the friction joints started. Most of this should be achievable by hand but you can use a hammer and a bock of wood to lightly tap the joints together. (Lay the block of wood on the stretcher and tap the block with the hammer – do not hit the stretcher directly with the hammer as this could damage the stretcher.)
Now that all of the joints are started, you can stand the stretcher up on an edge. Using the block of wood and hammer, lightly tap the joints together, working slowly around the entire canvas until all the joints slip into place.
Check that your stretcher is square by measuring the corners diagonally. If needed, rack the canvas until the stretcher is square.
Lastly, place the keys into the slots. You should have two at the corners and one at each intersection of the brace and bar. Simply insert the keys into place so that they stay put. Do NOT tap them so that they move the joint. At this time, you are basically storing them here so they do not get lost.
You are now ready to stretch your canvas.