Answers to Exterior Painting Questions

Q. When re-painting wood siding on a mobile home, is it recommended to sand right down to the original wood or just sand a little to rough it up and scrape away any chipped paint?

A. Pressure wash the siding to get rid of the grease and dirt that accumulates with time. Re-caulk all the windows and trim. Sand and repair the bad areas. Then paint away. If you go down to bare wood you will not only have to re-caulk, but you will have to prime and then apply one to two coats of paint.

Q. I primed with SW A-100 at least 36 hours before today's rain so I think that's OK. How long should I wait after the weather clears before top coating with SW latex Super paint?

A. Twenty-four to forty-eight hours after the rain stops usually are long enough. If it's a real concern, consider picking up a moisture meter and check to see if it's dry enough.

Q. We moved into our house last fall. It's badly in need of an exterior paint job. The south and west exposures are peeling badly in many places, though the east and north are really in pretty good shape. I think there's a name for the siding, but I'm not sure what it is - it's that vertically oriented striped wood - 12-inch centers between the stripes - some sort of composition board, I think. I'm planning on a similar color slightly darker, but not what I would call "dark" - a gray, or taupe in a satin finish.

1. Cleaning - Power washer or garden hose? Cleaner, soap or just water? There's no apparent mildew and while I'm not exactly sure just what "chalking" looks like, I don't think there's any of that either.

2. Sanding - I've seen a couple of threads where responses by moderators indicated that scraping loose paint is all you have to do, and that if you do choose to sand, to make sure all the dust gets washed off, otherwise you might get adhesion problems. So, am I better off not sanding? If I sand, is my Dewalt palm sander good enough, or do I need an orbital?

3. Priming - Only bare wood spots seems to be the consensus. Oil or latex, or is that one of those "everybody has their opinion" questions?

4. Metal gutters - not sure if they're steel or aluminum (probably alum), but the paint has peeled badly in many spots down to bare metal. I think where the latex still has good adhesion that no priming is necessary, but what about the bare spots, and can I use the same primer from question #3?

5. Paint quality - A lot of people seem to have a low opinion of the big box store's paint brands. Is Sherwin Williams the safest bet for a long lasting paint job? I'm willing to spend the money if it really makes a difference between five years for the paint job and 10+, but obviously, I don't want to if I don't need to.

A. 1. Rent a power washer. It will not only clean off the years of dirt/grime, it will also help knock off a good portion of the peeling paint, making the scraping portion a little easier. Make sure to use appropriate tip; you don't want to etch your name in the siding.

2. Scraping removes peeling/loose paint. Sanding only makes those areas that were peeled/scraped blend in better to the rest of the siding. Sometimes sanding near a peeled spot will reveal more loose paint that you might have overlooked by just scraping. A palm sander will work, but I prefer a piece of 80 grit wrapped around a 6"-8" piece of 2x4. Yes, dust removal is very important. I keep a dust brush in my back pocket as I prep/scrape/sand. A second power wash/hosing wouldn't hurt either.

3. Only bare wood is necessary, but hit any other areas that look like they might pose a problem. Mainly, right under a faucet/tap, under an AC window unit, anywhere that might take more than normal abuse. Since you said no mold/moisture issues, go with 100% acrylic.

4. Scrape the loose paint on the gutters, and hit that area/edges thoroughly with a wire brush. Wipe off dust, and prime with 100% acrylic.

5. The big name paints are your best bet. They became big name for a reason. Sherwin, Ben Moore, Porter, Pittsburgh, Muralo, etc. all have good lines of paint. Top on the list right now is Sherwin's Duration.
You mention spending money to insure a long-lasting paint job, but step 2 is just as if not more critical for a long lasting job. Almost 90% of paint failures lead directly back to missed/improper prep. Do a good job prepping, and the job will last for a long time.

Q. I need to spray paint a brushed aluminum patio table and chairs and don't think that cans of spray paint is the best way to go. Does anyone know of a paint I can use with a sprayer that would work on brushed aluminum?

A. Although you can get good (or cheap) paint in a spray can, they don't go very far. Most aluminum will paint well with oil or latex. If you have a little airless, you should be able to use either. If it is a conventional cup gun you will probably only be able to use oil.

Q. I'm trying to find out if a solid color stain can be sprayed onto the exterior of the house or does it have to be brushed on?

A. It can be sprayed.

Q. How can I remove paint spilled on asphalt roof by painters?

A. If it is latex or acrylic paint, try using water and a wire brush. Try this in early morning or evening when asphalt is not hot and sticky. The roof is hot during the day and any paint that gets on it dries instantly. It is next to impossible to get off. Hot solvents like lacquer thinner will eat the tar product in comp shingle or hot mop roofs. The easy fix is paint over it with something that matches the roof color.

Q. I'm going to paint a retaining wall in my back yard. Part of the wall is painted gray and another part is unpainted. Both portions have little spots on moss. Are there any tips to ensure the moss does not return and is there a special paint for concrete or cinder block?

A. The moss needs to be addressed first. Clean it with a solution of bleach and water, rinse well. The unpainted block should be primed with block filler. This will allow the finish coat to cover and not soak in and disappear. You can add mildewcide to the paint to help ward of the return of the moss. It is probably being caused by vegetation growing close to the wall and not allowing it to dry. Any good exterior latex is good for finish coat.

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