Dismantling old frames

[CalicoFraming]

I have to remove a stretched canvas from a knackered old frame. It's structurally sound, lots of gum tape on rear, mostly decayed but still well stuck to flat wood surfaces. Canvas held in place with nails.
Any suggestions / tips / warnings before I take it apart?
thanks!

[prospero]

Sounds familiar.

You can try teasing the nails loose by gently levering around the sides with a broad-bladed screwdriver. Little bit on one nail, then move around. If the nails are driven in at an angle, you can sometimes lever them enough so that a enough is sticking out to get a pair of pliers on.
If the shank of the nail is exposed at the side - between canvas and frame, you could saw it off with a hacksaw blade. Tedious process. I've sometimes cut them off with a Dremel + cutting wheel, which makes short work of it. Slightly alarming with sparks flying off, but you don't stress the canvas or frame this way.

[pichousepreston]

What are you doing with it once it's off, does it need re-stretching or is it being bonded down?