| 1) Roughing up the surface before repainting (of course).
And wash, with very hot TSP solution, or non-sudsing ammoniaif you can't get TSP -- something without soap in it.
| 2) Using a shellac-based primer for areas that are very worn and that need | priming.
Never use shellac outside. And even inside it's mainly used for sealing. For adhesion you want a penetrating primer, preferably with linseed oil if it's exterior.
| 3) Consider using an alkyd or oil-based paint instead of latex enamel for | possible better wear (they downplayed that idea, but am interested in that | option since latex based enamel doesn't seem to do very well in my opinion). | | I would be interested in knowing what others think about that last option -- | using alkyd or oil-based paint instead of latex enamel porch and floor | paint. |
I would never use latex/acrylic outside on horizontal surfaces. It simply doesn't resist water. It's also soft and tends to peel in a film. I avoid latex for anything but walls and siding stain. But the options are limited right now.
The whole issue has become a big problem. Good quality oil paints are being phased out faster than the technology can keep up.
I used to use urethane reinforced oil-base deck paint for steps and decks. I also used oil paint for trim and siding. In the 80s they came out with oil-base "stain", which will mostly wear off rather than peeling. So I switched to that where I could. It saves a lot of scraping down the line. Solid oil-base deck stains were also pretty good. That's what I have on my deck now. They don't last as long as paint, but they're easy to re-apply, while urethane reinforced paint is very hard to scrape.
More recently solid oil-based stains and deck stains are being phased out. The latex solid stains, while good enough for siding, are useless on steps and decks. They just wear away within a year. So there isn't any ideal solution. On my deck I'll probably try to hunt down another gallon of Cabot's solid oil deck stain for the next coat. After that? I'll be tempted to try some new "high-tech" solution like the new Sherwin Williams deck products. The problem with those, though, is that they're simply unproven. I can't afford to have people calling me back on jobs because their deck paint slid off the deck in a sheet and landed in the driveway.
(I actually remember a case like that in an article in Fine Homebuilding back in the 90s. California had set new paint regulations. A contractor used the new paint on a bathroom wall. The customer called back a few days later to say the paint had fallen off. The contractor assumed they meant it was peeling. But no, it was sitting on the floor like a length of curled-up wallpaper. :) Current paint technology is not much better than that. Acrylic paints are better than ever, but they're not *good* in the ways that oil paint was good. Meanwhile, the oil paints still available have mostly been downgraded -- thinner and softer than the older versions.
The entire building industry is faced with changes that are just happening too fast and may not all be good. Remember sprayed polyurethane insulation? It was the cat's pajamas 20-30 years ago for filling attic areas. Then it turned out the stuff gave off formaldehyde. When I come across it now there's also another problem: With age it gradually breaks down into a pile of very fine, choking dust. Yet spray insulation is the new must-have approach for new building. Will it work out? There's no way to know. Even if it turns out OK, I wonder about electricians trying to snake new wires later, in a house where every gap inside the wall has been filled with hard foam.
If I were building a deck for myself now I'd probably test-try the new Sherwin Williams product. If I had a more finished porch, with a roof, I might use the urethane-reinforced oil paint. I couldn't recommend anything else. But with that paint you may be cursing 10-15 years later, when your steps or porch look like a relief map of different scraped layers.