I was merely adding one data point and actually the brush I used was only 1-1/2" wide. ;^)> I was using a POR satin black finish coat on a frame that had been soda blasted and prepped with lacquer thinner and a Scotch Brite pad. Adhesion was not an issue, I have prepped for and brushed, rolled and sprayed plenty of paint in my day. The problem for me was that POR says no problem painting on with a brush, and actually recommends against thinning it for spraying. They also claim that when brushed it looks like a spray finish. I used the recommended foam brush and IMO it came out looking like warmed over s**t. IMO also the stuff has too short a pot life for brushing a large scale project with lots of nooks and crannies like a sportbike frame. By the end of the first coat, which took about three frustrating hours, it was like spreading glue on the frame. Perhaps if it could have been sprayed I would have been happy with it.
When you read between the lines, POR is not intended for clean metal. It's not really intended for alu and thus is probably not in the running for coating one of our panels. It's designed to seal rusty steel, plain and simple. When I learned about prep one of the lessons was if you still have rust, your prep is incomplete. After that experience I decided not to seal my gas tank with their sealer either. I ended up electrolytically and then chemically removing the rust and parkerizing the inside.
I stripped it off the frame with Scotchbrite, acetone a wire brush and a lot of elbow grease, then sprayed it with VHT black satin frame and rollbar paint. Three coats, each taking maybe five minutes to shoot. The VHT looks like a million bucks and scratching during reassembly has been a non-issue.
First shot is the POR finish. Too shiny for satin, lumpy and gluey. Second shot is the VHT. Smooooth satin and quite rugged. It is also UV resistant like the POR topcoat.
« Last Edit: June 27, 2014, 08:18:58 AM by Doc B. »
Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.