Just finished a remodeling job where I took out an existing closet
doorway and made a large opening with an arched top. Straight sides with
a circular arc on top. I used "bullnose" corner bead to make a rounded
edge all the way around.

The sides were easy: I used the metal/paper bead, which has two pieces
of paper (same as drywall tape) bonded to a thin galvanized curve. I
first tried to use this material for the arch, cutting segments into the
bullnose with tinsnips and then bending the bead to the arch. I *almost*
managed to make this work, until I noticed I'd nailed it up wrong so
that there was no way to hide the nails in the final result. So I ended
up tearing it out and replacing it with the flexible plastic stuff.

Using that stuff was a challenge, too: while it went up nicely, when I
applied a coat of mud over it, it left telltale "railroad tracks" where
the slices were, which looked pretty near impossible to get rid of. So I
ended up mudding the bead and laying a couple of layers of tape over it,
which I first soaked to make more flexible. This ended up working OK,
though I had to work over the tape pretty well to get out the wrinkles,
then cover it with another layer of mud to cover the wrinkles I couldn't
get rid of.

There's got to be an easier way. Anyone know how to make such a
rounded-edge arch?


--
Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral.

- Paulo Freire