More ladder time this evening, working on the cap trim of the roof facade. The hard part is the scraping of the old paint: the caps themselves are steel, not galvanized but I think coated with zinc, and unbelievably soldered together. The original paint was a sort of cream color enamel that was at some point painted over with a flat white latex. Whoever painted the last couple of coats just didn't bother with the scraping of the old paint or anything, and just really piled the paint on.
At this point, there is rust, but surprisingly little damage. I started off with a wire brush and a hand scraper, moved up to Frost's Nemesis (the 5HP grinder) with a wire wheel, but learned that a 5HP grinder on the top of an extended ladder has a definite gyroscopic effect and made me very nervous, so it was back to hand scraping. And I understand why the previous owner didn't bother with the scraping when he painted, though he made my life a lot harder because of it.
So I decided to try something: there's a spray-on graffiti remover called Goof-Off, which is basically Toluene and Xylene in a spray can.
It's made for spraying on unpainted surfaces that have been tagged, because it dissolves paint, and it works pretty well. It also dissolves a lot of plastics. Toluene and Xylene are both pretty aggressive solvents, but available in the neighborhood hardware store by the gallon. I think only MEK is a more aggressive solvent that's commonly available before you start getting into exotics like methylene chloride.
So I tried it. And lo and behold, it worked really well. It doesn't dissolve the old paint as much as soften it and release its bond from the metal, making it hella easier to scrape off. And it also has some reducing properties on the old rust, which help clean that up as well.
I didn't get all the scraping done, but what I did get I'm happy with. It's cleaned up enough that the new paint will adhere and cover over the old stuff quite nicely, and I don't need a primer on it first. And a spray can doesn't have the desire to toss me off a ladder.
I'm doing the back side of the house first as a trial. So far I like the way it looks; I'm spraying the caps with Hammerite Brown paint.
Hammerite is a special kind of paint that has microscopic hardened glass flakes in it. It's designed to be applied directly to metal, has extremely good properties over rust and provides a lot of weather protection. It gives an interesting appearance like ball-hammered metal; this stuff looks like hammered bronze when it's done
and it goes really well with the colors on the new siding. I am using the spray-on instead of the brush-on simply because of the ease of use. I love this stuff: if you saw the stanchions at CONvergence, the bases were painted with it. I got the idea from the Deep Space 9 set of the promenade; all of their railings were PVC painted with silver Hammerite. I'm also planning to use it on the composite sills, which will likely be done this weekend if weather permits. They may not be installed this weekend, but they should be at least formed and sheathed.
I'll post pictures when it's done.