THE PRACTICAL SIDE OF THE SAN DIEGO STUDY
AFTER THE SAN DIEGO UNIFIED PORT DISTRICT RELEASED FINDINGS of its study on alternatives to copper bottom paint, the consumer-reporting publication Practical Sailor offered readers its own perspective on the report. Here are highlights from that story, published in March 2011: San Diego port officials forwarded their “Final Report on Safer Alternatives to Copper Alternatives to
Antifouling Paints for Marine Vessels,” to the EPA in February 2010. Presenting data on a wide range of alternative antifouling paints that contain limited
or no harmful biocides, the 152-page report is based on both controlled panel tests and field tests on several different powerboats and sailboats that
berth in the port district. In the preliminary panel test, several mainstream paints that used a zinc biocide were effective, but because the goal of the test
was to find alternatives to biocides, very few zinc paints went on to the second round of field tests on boats.
The report includes an economic analysis of the annualized cost of using a paint that has no biocides. According to the study, once the application
and cleaning costs are amortized over the life of the paint, the costs of using a hard, slick, non-biocide paint are comparable to the annual expenses for
using copper-based paints. (Panels were cleaned every three weeks for the test.) However, the most optimistic cost estimates for non-biocide paints
rely on a five- to 10-year projected life span for hard, slick, non-biocide paints. The San Diego in-the-water hull tests lasted fewer than two years, so the
longer projections were based on manufacturer-supplied data from large commercial ships, the primary users of these types of paints. Nevertheless, the
study’s authors suggest that such lifespan projections are not unreasonable, as long as boat owners adhere to the recommended maintenance regimen.
The report concludes that the successful transition to a non-biocide paint will require close cooperation of regulators, boat owners, paint manufacturers,
boatyards, and hull cleaners. – Darrell Nicholson, Editor, Practical Sailor
marketed to boaters every year. Nicholson
says his testing has shown that many of
the non-copper, non-biocide products have
shown deteriorating results after 18 months,
some even earning “Poor” ratings as hard
growth is detected on test panels. But, he
notes, developing copper-free, biocide-free
paints is “an evolving technology” within
the coatings industry. “Copper is a com-
modity and it’s getting very expensive,” says
Nicholson. “So the manufacturer who can
make an effective eco paint without it, and
without any other biocide, will lower their
costs tremendously. It’s the Holy Grail for
paint manufacturers.”
For a full discussion of bottom paints
(formulations, uses, application, and main-
tenance of various products), visit the West
Marine Advisor at: www.WestMarine.com
and look for the “Antifouling Paint” article
posted there. Or, to request a copy via email,
contact: magazine@BoatUS.com. To see the
results of the Practical Sailor independent
tests of most marine bottom paints sold for
recreational power and sailboat use, how
they compare, and how well they worked
over time, visit http://goo.gl/WC2jt. Results
of the most recent tests, available to sub-
scribers, will be published in the March
issue of Practical Sailor.
