Extending the Life of Your New Paint Job

Posted by Practical Sailor at 08:43AM - Comments: (4)

Although a professional LPU paint job is usually sprayed on, you can save money by rolling and tipping, a two-person job in which one person rolls on the paint and the other follows with a brush. We compared brushes for rolling and tipping and described the technique in the April 2011 issue of Practical Sailor.

The results derived from a professionally applied LPU topside refinish are as dramatic as the invoice that accompanies the makeover. The shiny, wet look and the protection it affords can last for years—whether it’s three years, five years, or nearly a decade depends upon how kindly the rejuvenated surface is treated. Two-part polyester urethane coatings such as Awlgrip II are tough, gloss-retaining coatings that will put up with some abrasion, but if you make it a regular occurrence, both the gloss and the paint will eventually go away. 

Giving your topsides proper maintenance attention, like waxing regularly, will keep them looking healthy.

  • During application: Most well-executed LPU paint jobs begin with epoxy primers and fairing compounds as the underpinnings of a glistening LPU topcoat. When it comes to longevity, applying enough “mil thickness” of paint is paramount, and each paint manufacturer specs out a wet thickness or volume of paint per given amount of surface area by which the applicator can determine when enough material has been applied.
  • Cleaning: Regularly sponge washing the hull is the first step in preserving the topcoat’s shine. Avoid cleaning with scrub pads and gritty cleaners; this should be a completely non-abrasive effort. Many paint makers offer their own mild detergent, and we’ve found Awlwash by Awlgrip to be a very effective, completely non-abrasive cleaner. The purpose of these regular washdowns is to remove dirt and chemical residue transferred to the topsides by atmospheric deposition. Over time, such contaminants will diminish gloss and trap grit, increasing the abrasive effect that fenders have when they rub against the topsides.
  • Sailing is not a full-contact sport: More often than not, the decision to have the topsides re-painted has to do with localized damage that resulted from docking maneuvers gone awry, tussles at the starting line, or storm damage when a line gives way. Those who can avoid such bumps and bruises can nurse the gloss for many more years. Eventually the surface will need to be repainted, but if there is a minimum of dings, scrapes, and damage, and the primer is intact, the paint prep process will be much less invasive and the cost of extensive fairing will be less.
  • Wax On-Wax Off: After the first two or three seasons of washing and protecting the surface from winter-cover abrasion and line chafe, there’s often a need to tune up the gloss a bit. The best bet is to follow up another good washing with a conventional carnauba-based wax like Mother’s California Gold or Collinite’s #885 (PS’s Best Choice for paste waxes, July 2009). The reason for using this wax rather than a deeper-penetrating copolymer polish is that at some point, repainting the surface will be in the cards and polishes that reside deep in the porosity of an aging finish are hard to remove and can cause possible surface contamination. The same goes for silicone-based shine restorers that can make a surface gleam, but leave behind a coating that can cause fish eye craters and poor adhesion in the next coat of paint.
  • Breathe life into dull coats: Owners of boats with five- to seven-year-old intact LPU paint jobs that look dull but remain well adhered, can try rubbing out the surface with 3M Perfect-It rubbing compound and following up with a carnauba wax. In such cases, the gloss often can be readily restored, but as with older gelcoat, the new shine is derived from the smoothness of the surface and the wax, not the paint coating alone.
  • Repair care: Repairs to two-part LPU coatings are a true test of product awareness and applicator talent. The challenge lies in blending the old and the new, and blending the circumference known as the “overspray region.” Matching color change and gloss variation is even tougher than automotive work. The reason for these difficulties is the quality of the paint itself. Polyester LPU coatings are so tough that attempting to rub out the overspray line associated with a repair can result in too much heat and the dulling of gloss around the perimeter of the new paint. Picking the right time to buff back this boundary between new and old paint, and using the right rubbing/polishing products is a well-kept trade secret among craftsmen. Most love the 3M products Perfect-it, and Finesse-it.

One of the reasons why AwlCraft and other slightly softer and more user-friendly acrylic-based LPU paints are growing in popularity is that they are much easier to repair and buff than polyester-based two-part paints. Their longevity is good, but not quite that of old standby Awlgrip.

If you are planning a new paint job and looking for a durable, long-lasting finish, the December 2012 issue of Practical Sailor compared linear polyurethane paints after three years.

Comments (4)

Thank you for this article on painted surfaces. So much is written about taking care of gelcoat that of us with painted hulls often feel forgotten. My word to the wise is to think three times before ever painting over gelcoat as that is the entrance to a world of no return. Do you best and learn to live with it.

~ ~ _/) ~ ~ MJH

Posted by: MJH | March 11, 2018 1:49 PM    Report this comment

As to repairing spots on an LPU painted hull: I found it impossible to blend in the repainted "patch" with the surrounding hull. No amount of rubbing compound seemed to create an actual "blending" of the surfaces. Instead, I now tape off the area to be repainted with masking tape; sand within the masking taped area (this often tears the masking tape, but I just replace it when I'm done); wipe with solvent; and paint, going over the masking tape to insure total coverage within the masked area. When the tape is removed, there is a very noticeable ridge of paint along the tape line, but I've found that if I CAREFULLY, LIGHTLY sand that ridge with 400 grit sandpaper and then compound the area around the patch perimeter, it blends very nicely. Naturally, the repainted area will be more shiny than the adjacent, older paint but from a distance of a few feet, you really don't notice it. Plus, a little wax helps to equalize the shine. I use the Interlux wax that is formulated specifically for the Interlux LPU paint.

Posted by: Rigoler | February 23, 2018 6:17 PM    Report this comment

As to repairing spots on an LPU painted hull: I found it impossible to blend in the repainted "patch" with the surrounding hull. No amount of rubbing compound seemed to create an actual "blending" of the surfaces. Instead, I now tape off the area to be repainted with masking tape; sand within the masking taped area (this often tears the masking tape, but I just replace it when I'm done); wipe with solvent; and paint, going over the masking tape to insure total coverage within the masked area. When the tape is removed, there is a very noticeable ridge of paint along the tape line, but I've found that if I CAREFULLY, LIGHTLY sand that ridge with 400 grit sandpaper and then compound the area around the patch perimeter, it blends very nicely. Naturally, the repainted area will be more shiny than the adjacent, older paint but from a distance of a few feet, you really don't notice it. Plus, a little wax helps to equalize the shine. I use the Interlux wax that is formulated specifically for the Interlux LPU paint.

Posted by: Rigoler | February 23, 2018 6:17 PM    Report this comment

As to repairing spots on an LPU painted hull: I found it impossible to blend in the repainted "patch" with the surrounding hull. No amount of rubbing compound seemed to create an actual "blending" of the surfaces. Instead, I now tape off the area to be repainted with masking tape; sand within the masking taped area (this often tears the masking tape, but I just replace it when I'm done); wipe with solvent; and paint, going over the masking tape to insure total coverage within the masked area. When the tape is removed, there is a very noticeable ridge of paint along the tape line, but I've found that if I CAREFULLY, LIGHTLY sand that ridge with 400 grit sandpaper and then compound the area around the patch perimeter, it blends very nicely. Naturally, the repainted area will be more shiny than the adjacent, older paint but from a distance of a few feet, you really don't notice it. Plus, a little wax helps to equalize the shine. I use the Interlux wax that is formulated specifically for the Interlux LPU paint.

Posted by: Rigoler | February 23, 2018 6:17 PM    Report this comment

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