One exterior painting problem that many homeowners encounter is peeling gutters and downspouts. It’s quite annoying… actually. The rest of the paint on your home seems to be weathering normally, but your gutters and downspouts shed paint like a river birch tree sheds its bark on a bad day.
Gutter peeling is typically common to galvanized metal gutters.
The problem exists because the wrong paint was used for the first coat on the gutters and downspouts. The most common mistake I have seen, is applying oil base paint directly to the bare galvanized metal. It will not last longer than a few years.
The test I have run over the last 26 years points to oil base paint being applied to bare metal as the primary culprit. Ninety percent of the time the painters working for the builders made this crucial mistake.
I also found that most oil base primers will not properly bond to galvanized metal. I have found that a primer that is cement based bonds very well to galvanized gutters. Porter Paints carries a product call Porter Guard Galvanized Metal Primer 290. It contains cement and it does a great job of bonding long term.
If you are reading this article and have problems with peeling gutters, there is good news and bad news.
OK, here is the bad news. Be prepared to either strip all your gutters back down to the bare metal and start over, or be prepared to service your gutters on a fairly regular basis. Scraping and priming will not re establish a bond in areas that have not peeled yet. Putting primer and top coat on all your gutters at this point will not reestablish a bond. It cannot penetrate trough the existing paint and cause the defective paint underneath to re-bond to the galvanized metal. You will continue to develop peeling on these metal surfaces over time.
The good news is you can eliminate what is peeling now and prime the bare metal with the primer I mentioned above. It will stop the peeling in those areas.
Here are a few important steps you will need to take.
1. First you will need to remove any peeling paint from the downspouts and gutters with a wire brush, or scraper. A wire wheel on a drill also works well.
2. Clean the sanded area with a good grade of solvent to remove any oil on the surface. Wipe down the metal areas with a heavy coat of solvent and allow it to totally evaporate.
3. After the solvent has evaporated, apply the cement based metal primer paint directly to the bare galvanized metal spots. Allow the primer to dry according to manufacturers recommendations and then apply either latex paint or oil base paint as a top coat.
It’s possible to use latex paint instead of primer.
If all the oils from the bare metal are removed, you can even re coat the metal with latex paint instead of a primer if you so desire. I have found through the years that if the surface has been properly clean, just plain latex paint will bond to bare galvanized metal much better than oil base paint.
Complete the project using a top quality house paint. Use two coats in extreme cases.