What happens when bilge paint stays underwater? In a boat-show conversation, J.P. Ferris of Axalta Coating Systems explained why the answer depends on the coating, its preparation and the length of exposure.
At the time of the interview, Ferris brought a 35-year painting career spanning boats, yachts, aircraft and other applications. The discussion focused on two finishes found in bilges: urethane coatings and gelcoat.
Urethane coatings and prolonged immersion
“Urethane coatings, if left submerged, can develop blisters and begin to delaminate,” says J.P. Water beneath the coating can lead to bubbling, flaking and peeling.
Asked how quickly that could happen to a fresh coating, Ferris described a range from a week to months, depending on preparation, film thickness and time submerged. That was a conditional explanation, not a fixed lifespan for every paint system. Repairing damaged paint can involve removing the affected coating, preparing the surface and repainting.
An example of a finished bilge compartment.
Gelcoat can still show staining
When it comes to gel coats, “water can permeate, but it’s a lot more stable. [Standing water] is not as big a problem [on gel coats as on urethane], but it is very unsightly,” says J.P.
He also describes the cleaning cycle that staining can trigger: “the staining can get oily and ugly, and boat owners will pour degreaser, acid, and bleach down there to try to clean it up.” That observation is a reason to address recurring water and contamination, rather than treating the visible stain as the whole problem.
Check bilge paint for prolonged water exposure
Ferris’s comments point to a practical starting point: identify the finish in the bilge and follow its manufacturer’s care instructions. Check where water remains, investigate new water entry and inspect the coating for damage.
Arid removes residual fluid from the areas served by its pickups. Reducing standing water addresses one source of prolonged exposure, but it does not repair a failing coating or replace appropriate cleaning and surface preparation. Read how the collection and discharge cycle works.
An engine-room photograph from the Arid archive.
More from J.P. Ferris and Axalta
Read Ferris’s contribution to Bayliss Boatworks’ discussion of marine finishes, explore Axalta’s marine coatings, or visit his LinkedIn profile.
