I've made a couple of furniture and applied stain and polyurethane with
brushes. After 5 coats of poly, at some places, there's still some marks
from the brush (but only I knows where...). Anyway I tried the new poly in
spray can and I must say that the finish is perfect.

So I wonder if I should consider buying a spray gun to apply my poly and if
so, what special thing I should look into (equipment and space)