This is one way to restretch a wood framed screen. This is the way I do it when in a pinch.
This should only take about 20 minutes to do once you get comfortable with the process, and only costs as much as the screen fabric (and your precious time). If you are familiar with stretching canvas, this is basically the same idea. Your hands will probably be sore after doing a couple of these.
You need your old frame, cleaned up and old screen removed, some new screen material, a stapler, lots of staples, a hammer (to hammer down staples that don't go in all the way), and some scissors. (and beer)
Cut your screen fabric to make sure it will fit.
You'll need a bit to hang off the edges, enough to grip on and pull.
OK - now for the actual stretching.
The first thing you want to do is make sure the screen fabric is lined up, and we're going to tack the screen to the center points of the four sides of the frame to form a cross, this helps establish our basic stretch, and anchors it so the fabric doesn't get skewed all over the place.
First: tack the side away from you
Then: near you
then the other two, I go left to right...
And now you have your cross, the screen should be a bit taught in the center but have a lot of slack in the 4 quadrants.
"How do you stretch it to maintain a uniform tension, without skewing the fabric too much?" you must be asking. Well, the way you do that is to start at your stretch center-points and move outward to the corners. Do this on one half of one side at a time, rotating the screen as you go. I usually go with the top right half of the side and work clockwise, you can do whatever you want.
once you have completed those sections, turn around and go the other way, making sure that the fabric is evenly tensioned across the whole frame.
Work your way toward the corners, pulling the tension with you. You want to makee sure that you're not pulling one side so much that the other side loses out, try to balance the tension between the sides.
if you're lucky, after a few "practice" frames, you will end up with a screen that has pretty even tension across the whole mesh, from side to side and corner to corner!
cut off the extra screen fabric around the edges and hammer down those pesky staples that didn't want to go in.
now you have a fresh screen that is ready to print!
I recommend cleaning the screen with a degreaser before you coat it since your dirty greasy mits have been all over it.
Good luck, and keep it metal.