Secret to painting galvanized steel
White vinegar to the rescue
October 28, 2009
By Bill and Kevin Burnett
Inman News®
Q: I have galvanized steel railings that were painted a few years ago with two coats of epoxy paint. Now it is peeling off in large chunks.
I can't seem to get a definitive answer from the painters I've asked as to what paint to use and how to apply it. Recommendations have included everything from Rust-Oleum to oil-based paint to using epoxy again. I was hoping you could steer me in the right direction.
A: The secret to a long-lasting paint job on any surface is in the preparation. A good-quality paint should not fail after only a few years.
We're sure the paint is not the problem. The cause of paint peeling from galvanized metal is failure to do sufficient preparation. Here's how to redo the job right.
In his first career, Kevin painted thousands of feet of galvanized gutter. The first thing he always did was wash the surface of the metal with a mild acid. The galvanization process leaves a smooth, oily film on the finished metal that doesn't hold paint very well. Treating with acid etches the metal and gives the surface a "tooth" for the paint to adhere to. Kevin's acid of choice was plain white vinegar. He came out smelling like a salad, but he never got a call back for peeling paint.
To repaint your rails, start with a thorough prep job. First scrape off all the peeling paint and feather the edges with 150-grit sandpaper to blend the old paint into the new. Sand the rest of the rail to roughen the old paint.
The final prep step should be a quick wipe of the bare metal with the vinegar. This added step takes little time, costs nothing and provides insurance against repeat peeling.
Paint the bare metal with primer designed for metal. Finally, paint the rails a color and paint of your choice. We've always had good luck with acrylic latex, but any good-quality paint should do the trick given the superior preparation we know you'll do.
Q: I would like to get your advice on air duct cleaning. The ad for this service claims it will lower the utility bill and improve air quality in the home. It also offers a large discount, so I guess it is an expensive procedure.
We have lived in our home for 15 years and never had this service performed. Do you think that cleaning the air ducts is something that should be done, and will it result in lower utility bills and better air?
A: Unless you've got giant hair balls in your heating system, we can't see how cleaning the ductwork will lower your heating bills. It can improve the indoor air quality, but you'd be better served by changing the furnace filter regularly.
A few years ago our mom moved into a new home that Bill purchased for her. She has sinusitis. One of the first things he did was to have the heating ducts cleaned in hopes she would get some relief. It helped her breathing some, but it certainly wasn't a cure-all.
Basically, duct cleaning involves vacuuming out dust and dirt using a large vacuum cleaner that is mounted on a truck. If you regularly change your furnace filter, the need for this deep cleaning should be minimal.
In a forced-air heating/cooling system, inside air in the home is recycled. Air is drawn in through the return air ducts to the heating unit, where it is heated or cooled. Before reaching the heater itself, air must pass through a filter. Conditioned air is then blown from the unit through the supply ducts into the home.
We probably would not recommend duct cleaning as a regular home maintenance item. The exceptions would be once after initial construction to get rid of construction dust that may have infiltrated the system, or if you live in an exceptionally dusty area.
Your pocketbook would be better served by changing filters every three to six months. If dust is really an issue, have an electronic air filter installed in the heating/cooling unit.
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