I'm in the 'keep it simple' school. You don't want to put latex on bare metal (unless it's acrylic), but you don't have bare metal there. In your shoes, I would scuff that lightly with some 100 grit sandpaper, then wipe it down with a rag with some acetone. Then paint. I use a roller. Because, you know, it's a garage.
With a semigloss, it'll look fine. All of the green in this picture is cheap Weatherbeater paint and a cheap, disposable roller from Harbor Freight.
(High gloss will bring out every imperfection in the cabinet.)
Ummm, Jack, "latex paint" is kind of a general-purpose term for a water-based 'permanent' paint (as opposed to say an artists watercolor paint or an artist gouache). The 'better' "latex paints" use a 100% acrylic resin binder in the paint (paint is pretty much binder to make a final dry paint film, pigment to give the paint its 'color', and a solvent to let you use the paint in a liquid form. Other 'stuff' may be added to make those three main ingredients all work together 'better' or in different ways, but that is paint in a nutshell.)
btw, there is no "latex" (natural latex rubber) in "latex paint".
http://dundean.com/tips_what_is_latex_paint.shtml
http://www.californiapaints.com/Pro...ics/Before-You-Begin/Choosing-Paint-Type.aspx
As to putting a water-based paint onto metal, sure. Clean, prime, paint.
Yes, to a semi-gloss paint as opposed to a high-gloss paint (which does show every 'imperfection' in the substrate or the application/technique).
More than one way to skin a cat. Brush, or roller, or sprayer can all work.
+1 on Floetrol with a 'latex' or acrylic housepaint.
If using a water-born automotive paint, RTFM.
Pretty much RTFM of the paint you are using and see what it says about application methods and thinning (or not thinning).
As to using acetone to clean, be careful. Acetone is a relatively 'strong' solvent. It can soften or remove a lot of paints (especially some 'latex' paints). Which then means you may have to completely strip and remove the gummy/goopy paint down to bare metal or whatever.
Clean the cabinet, scuff sand (or use a 'liquid sander' prep material, see the paint store), then evaluate the condition of the underlying paint. And depending on just what 'level' of paint finish you are going for, paint or prime-n-paint.
As to just taking some houehold 'latex' paint and putting a touch of water in it and then spraying it with a spray gun, generally
nope.
RTFM for your spray gun and see what viscosity (thickness) of material it can successfully spray.
An airless sprayer (high-pressure pump) can usually spray most acrylic/latex paints without much (if any) thinning. Some Floetrol may help the paint to flow (hence the "Flo" in Floetrol) and lay-out a bit better as opposed to just putting in water (over-diluting water-based paints with plain water often results in a weak final paint film, which then doesn't stick or have the original durability. Extreme levels of thinning with plain water results in paint 'dust' because the binder is so thinned out that there is nothing really left to make the actual paint film and you mostly just have the pigment 'dust' on things).
A typical spray gun (high air pressure type) or an HVLP gun may or may not be able to successfully spray 'latex' paint, depending on the needle/tip size and the air pressure and the air flow.
RTFM for your gun and see what it says.
