by Ron Joseph
Painting Vs. Powder Coating
Q. I am close to having wrought iron fencing installed on our residence. It's
a large project and one that I would not want to maintain painting frequently
(every 5 yrs). All bids had speced powder coating vs painting, except one company
who beleives that his method is jsut as good, which is to dip into paint. He
stated that this will seal all areas such as welded joints, whereas the powder
coat won't. He guaranteed that the paint would last at least 15 yrs. How much
of this should I beleive and should I request that he powder coat? (he provided
that as an option but said I could save that money, "its not worth the
A. The job is only as good as the surface preparation. Regardless of whether
liquid or powder coatings are used, you must insure that the contractor has
a well controlled pretreatment process. The liquid paint might be OK, but will
the contractor apply a primer over the pretreatment? What type of coating resin
will he use as the topcoat? Have the contractors (liquid and powder) specified
the film thickness that they will achieve? Have they specified the resin type?
Have they told you how they will prepare the welds to prevent early onset of
corrosion? How will they confirm that the welds will be properly coated? Have
they been in business long enough to be able to stand by a warrantee of 15 years?
In summary, both liquid and powder coatings can do a great job if the coatings
are properly applied.