by Ron Joseph
March, 2004
Repainting Metal Doors with Latex Paint
Q. I have 2 steel entry doors that are 24 years old; they both face south and
do not have storm doors. The paint has peeled off and stripped the factory primer
in some small places over the past 6 years. Each year, we scrape, sand and wash
the bare areas, re-prime and put a latex exterior paint over. And each year
the same spots peel off again. We have tried every type of primer and none seem
to work. Any suggestions or do we purchase new doors?
A. You shouldn't need to buy new doors.
It sounds to me that the surface under the primer is not as clean as it
appears to be. If you are experiencing failure in the same location time
after time, and when using different products then I would be suspicious of
the surface.
Each year you scrape the surface, loosening any failed paint, sand the bare
metal with a fine grit sand paper, and then wash the bare spots. Each year
the paint fails in the same areas.
What do you wash the metal with? Be absolutely certain that there is no
grease, dirt or sanding dust left behind prior to applying the primer and
top coats.
After the scraping, sanding, and washing, use a clean rag and wash the
surface down with a lacquer thinner solvent before you apply the primer. You
might also consider using a acid etch wash primer and spot prime the bare
metal areas first, then apply a good exterior grade primer and top coat
system. Follow the manufactures recommendations for application and dry
times, these can be very critical
I recommend that you visit the local paint center and tell them what has
occurred over the years. They will be able to recommend products for you to
use to help prevent this from happening again in the future.
Please be aware that coatings and solvents are chemicals and therefore you
should always pay attention to proper handling procedures and be prepared to
wear protective clothing, such as respirators, gloves, coveralls, etc. For
further information on the health and safety requirements for the coatings
and solvents you wish to use we strongly advised you to contact your local
coating supplier. If possible, go the extra step and look for this
information on the website of the product vendor.
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