I just bought one of these harbor freight powder guns and some of their coating.

Have never done this before and was wondering how much overspray can I expect with this?

I want to build a nice, small chamber to spray into (and maybe be able to recover some of the powder?) (or is that worth the effort?)

How much powder do you end up wasting?

For example, HF sells a 4.99 (looks like a pint) container -- what percentage gets on the piece? (I'm sure technique matters but "generally"). thanks