I'm a light freak. I want my work area lit up like an OR in the hospital! In my case I didn't have to deal with a brick wall but it really doesn't make any difference. On my plywood walls I Kilz'd it then sealed it. After all was dry I went back with 2 coats of high gloss white enamel. Over the years I've found enamel easier to keep clean vs. latex. I then hung a 4' x 4 bulb florescent switched fixture over the lathe. I couldn't be more pleased. There's no glare as one might imagine, it reflects the light perfectly and as mentioned prior, is a snap to clean. In your situation with brick walls I'd go a little different route though, much like I did in my shop kitchen behind the sink for a backsplash. I used plastic designed to use as tub surrounds in bright white. It comes in 4' X 8' sheets and is really easy to work with. There're several ways to affix it to your brick wall. (I can post pics if you think it would make it clearer) If it were me, I'd fir it out with 1" X 2" fir strips anchored to the brick then screw the panels to the fir strips with short drywall screws. (also available in white. If ya can't find white then just daub some paint on the heads when you're finished.) Added bonus #1 would be the ability to hang shelves, pegs or whatever strikes your fancy for handy storage right by the machines. Bonus #2 is in the event you ever moved the machines and want to go back to your original brick wall you just unscrew the panels and fir strips caulk the anchor holes with color matching putty and it's like nothing ever happened.
Just my $0.02 but HTH,
Dale
Just my $0.02 but HTH,
Dale