Even with finished basements and false ceilings it is sometimes not possible or feasible to cover all of the ductwork. By painting it you can at least disguise your home's inner workings and make it look a little more attractive.
An important note to keep in mind is this article is written specifically for people who want to address their ductwork, but these same steps and the product in this article can be used on numerous other products. Simply apply a little creativity and you can camoflague the galvanized metal on your eaves, a tin ceiling, an old metal shed, fencing, or craft projects. So don't let the narrow focus of this article hamper your creativity.
That being said, we're also going to focus on the Benjamin Moore & Company's IronClad Latex Low Lustre Metal & Wood Enamel. Although other reputable companies have their own products that perform similar functions and just as well, the author of this article has had personal experience with this product and can vouch for its effectiveness.
Before you begin painting your ductwork you'll need to prepare the surface. This isn't always a required step for painting projects but, in this case, it's absolutely necessary and it can be labor intensive. If you have newer ductwork you'll just have to scrub it with mineral spirits to make sure that it's free from all dust, grime and oil. Even if it's brand new you have to scrub it with mineral spirits.
If you've got an older duct system you may have a little more work on your hands. Use a scraper, sandpaper, SOS pad or a wire brush to remove all loose rust, dirt and debris. If any of this duct work (or your other projects) are outside then you'll need a power wash to remove all salts that accumulate on exerior items.
Ducts with a shiny metal finish will require you to dull the surface by abraiding it with sandpaper or an SOS pad. Do this prior to any cleaning as it will leave its own dust behind.
Mildew is another obstacle. Unfortunately, mildew is a hearty foe and requires a special wash designed to kill it. If you don't use this product you'll most likely see the mildew in the future as it will spread and grow through your painted finish and then removing it is even more difficult. So make sure to get a commercial mildew wash and scrub well.
Once your surfaces are prepared you're ready for application. You can either brush, spray or roll the product on, whichever method suits you best. The product is extremely "thin" and requires a lot of stirring during the process, even if it's sitting in a paint tray. You can thin it if it's become old and thickened a little but do so only with a small amount of clean water, much the way you'd thin any latex paint.
The reason this product is so useful is because it works as a primer and topcoat all in one. You can have the IronClad Latex Low Lustre Metal & Wood Enamel tinted to your color selection so you don't have to go through the trouble of priming and then painting the ductwork. It also has less odor than some other products and is easy to clean up. Tinting to match your paint color is highly recommended.
The manufacturer says that one coat will protect and preserve while two coats provides greater durability. In all actuality you'll need at least two coats and probably more to create a nice even coverage that properly reflects your color choice because the product is very thin. Especially if you're trying to get your ductwork to match your walls. If you're working on an independant project then that many coats may not be necessary.
Cleaning up after painting ductwork is just like clean up after any latex painting project. Generally hot water is all you need but a little soap can't hurt. Never use turpentine. If you're using a sprayer you'll need to follow the specific instructions for clean up but a mineral spirit rinse is generally a good idea.
