How to Paint Your House (and why you may not want to paint your barn)

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Although it’s not essential to remove areas of old paint that are rock solid, you must go back to bare wood in places where peeling, bubbling and cracking is visible. And where your pressure washer and wire wheel can’t make this happen, you have two main options, both of which have drawbacks. You can soften old paint chemically, then scrape it off, or soften the paint with heat and scrape. Traditional paint-softening torches pose a fire hazard and vaporize toxic lead from paint if it’s heated higher than 1,100 degrees. Standard stripping chemicals, on the other hand, are messy, expensive and toxic. So what do you do?

Safer chemical strippers are one option, and not only because they pose a substantially lower health risk than traditional formulations. Newer versions also work better because most don’t dry out. Brush them on and wait as long as necessary for softening to be complete.

Although softening paint with an open flame can fill your body with vaporized lead, there are two related approaches that won’t. Electric heat guns that operate cooler than 1,000 degrees are claimed to be safe for use with lead paint. A more effective option that operates at an even lower, safer temperature is an infrared paint stripper. This is a hand-held electric tool that uses heating elements to warm painted surfaces from a distance of several inches, softening the paint and making it easily scrapeable. The model I’ve tried — the Silent Paint Remover — works more quickly than a heat gun and performs well on curved surfaces. The infrared heating action is also effective for softening glazing putty when refurbishing traditional wooden windows.

With the bad paint gone, what have you found? If there’s rot and punky wood present, you’ll need to scrape out the soft stuff, solidify any remaining spongy areas with wood consolidator, then fill the cavities with an epoxy-based filler. Do not use auto body compound. Auto body products are too brittle for use on exterior wood; it’ll simply crack and fall out in short order.

Is any of your wood gray and weathered where paint has been flaked off for a while? That color indicates surface deterioration caused by UV rays and microbes. The cellulose is breaking down under ultraviolet attack and beginning to detach from the underlying wood. Look closely and you’ll see that weathered wood is also fuzzy. Although this kind of surface is certainly absorbent, it’s not physically strong. This means that even though finishing products can soak into old wood, the grip they gain on loose fibers isn’t sufficient. The finish layer ends up coming off quickly, along with the wood fibers underneath. Sanding is the solution. You’ll find a random orbit sander excellent for many areas. A belt sander is better for wide open, flat regions.

New Wood Preparation

Prepping properly before repainting is a lot of work, but it’s essential and prudent. Just don’t make the mistake of thinking that prepping new wood is much easier than it is for old. Once you paint or stain, you’ll need to stick with some kind of finishing regime. Shabby paint is much worse looking than no paint at all. And since exterior wood finishes don’t add significant rot resistance to the material, it’s mostly about looks. For a rare, one-time wood finish option for new wood, see “One Time Only? (below).”

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