drywall
Is drywall tape required for a patch to a small hole that's fastened only to the surrounding drywall sheet?
Specifics – I have a round hole, about six inches in diameter. I've patched it with a round piece of drywall. Drywall screws hold the patch to a board, and the board to the surrounding drywall.
For small holes like you describe, I'd use Light Weight Spackle rather than standard vinyl Spackle. The Light Weight Spackle is very easy to apply, will almost disappear in small pin holes, and you can smooth it off with a damp cloth apx 15 minutes after application. using a damp cloth also removes excess Spackle from surrounding paint so the only patch material is in the hole, not on the surrounding paint. You can get small sample size containers of paint at HD or Lowes for a couple of bucks. Pick a close color from the cards and touch up your fixes without having to buy a gallon of paint.
I wouldn't try removing the frame. It appears to extend in both directions and may damage a larger section of wall.
You are right to be concerned about taping compound or spackle sticking to a metal edge. I would recommend making a patch that is larger than the opening by about an inch on each side. Then trim away the back paper and the core of the patch so that the part being put into the wall is the exact size of the hole. That will leave you with a "flange" of paper facing on hte room side that will be easier to tape and compound to blend it in.
Your general approach to support is right, but you may not need a brace between the studs. To support the patch, cut three pieces of 1x2 wood that are about 6 inches longer than the height of the opening. Position each piece of wood vertically in the cavity, one near the left side of the hole, one in the middle, and one near the right. To attach each strip pull it forward against the back of the plaster or plasterboard. Hold it in place by screwing through the face of the wall into the top and bottom sections of the wood strip. You can screw the plasterboard patch to these strips for support.
Finish the attachment with tape and taping compound. I would probably use mesh tape on a patch of this size and support.
Best Answer
A hole that size should be taped to prevent cracking. You don't need to use tape though. Another method uses the patch piece of drywall's paper:
Square the opening to be patched.
Cut a pice of drywall about 4" x 4" larger then the hole.
Score the back side of the patch piece of drywall along lines 1 & 2, about 2" in from the end.
Place the drywall face down on a table, lining up the score line with the edge of the table and snap it along the line.
Repeat steps 3 & 4 for score lines 3 & 4.
Peal the outer edges of the drywall off leaving just the front paper so that your pice looks like fig 2.
Place the patch pice over the hole and mud.