?How Badly Won't Perfection Stick to Previous Coat of Perfection?

[rardiH36]

Sorry about the sort of double negative of this posting's title.

Has anybody else had the following described problem?

I have had good success with Perfection (2-part polyurethane) to:

1) Paint my cabin top and also my cockpit sole and seats (with the addition of flattening agent and Interlux's anti-skid granules) about two years ago.

2) Restore the deck's non-skid (with the addition of flattening agent and Interlux's anti-skid granules) about 6 months ago.

But as part of 2) I also decided to add a refresher coat to the previous "Perfectionized" cockpit seats because the new deck color was slightly lighter than the 2-year old paint. For surface prep, I quickly found it not possible to sand the seats since they had the non-skid texture. So I just wiped down the seats with solvent and then painted. The seats had never been waxed or cleaned with a wax impregnated wash. The paint went on well with no fisheyes and good coverage. So I assumed a successful job.... Until a couple of weeks ago when a winch handle dinged the finish. I noticed that the paint flecked up all around. A blast with the dock hose began to lift up the paint, revealing the 2-year old coat of Perfection underneath. I took the seats off/home and proceeded to pressure-wash the newer coat completely off. (See photo of the "X Marks the Spot" design with the first pass of the pressure washer.) With the pressure washer I was able to completely blast off the second coat of perfection from the seats. I now have reinstalled them with the 2-year old coat looking just as good as before I covered with the second coat.

Regarding the painting of the main deck non-skid. The surface was still the original 1980 finish, in good structural shape and only mildly oxidized. But cosmetically much in need of improvement. Seemed it had never been waxed. So surface prep was a good water/soap scrubbing and a stiff brush "wipe-down" with acetone.) The Perfection on this surface latched on just fine. It doesn't even scrape off with the edge of knife without taking the sub-surface with it. (By-the-way: The result of the non-skid application looks great. Virtually as nice as a new boat.)

Seems two possible reasons for the failure on the seats:

- Perfection just won't stick to itself once the underlying coat has fully cured?

- I painted the seats after the main deck was completed. I needed to add more of the 2333N special thinner. Maybe the mixture had begun to kick and I extended too long with the thinner. The paint would have been about 2 hours old.

Look forward to comment -- before I look to paint my boom with the appx 25% of (unmixed) perfection I still have from the first project.

 

[Tim R.]

Perfection needs to be recoated within a certain time or you have to sand.

Perfection info sheet

 

[tommays]

From what i have seen on my mast project you would have to sand it down as there MAX recoat window is about 48 hours

 

[rardiH36]

Yep, I did read about the next-coat-will-stick window in the spec sheets. And I suspected that this would be a major factor is why mine second application failed. But after 1.5 years, I was hoping for enough oxidation and pitting from sun and weather to provide a grippable surface.

What this leads to is that a major downside to 2-part polyurethane on non skid is that at the next repainting further down the road (hopefully 5/10 years if I still have the boat), I will have to find a primer that will stick, or will have to sand the non-skid texture completely down flat. Then re-texture somehow. Not a job I look forward to.

 

[sailormanbigd]

i would think that the problem lies with not getting a bite on the previous surface. If you were unable to sand due to texture you should have at least used some scotch brite pads to scuff it up before painting. I am not familiar with the liquid sanding products on the market much. I would use it to soffen latex enamel on doors and jambs before painting, because you can't sand latex- but not sure if it would have same effect on "perfection".

 

[Barnacle Bill]

Sailormanbigd has the answer. Paint needs to have a tooth to attach permanently. You would have been better off to sand the nonskid anyway and then reapply the new coat. By not sanding you had no "tooth" and so the paint didn't hold.

 

[Jumpstart]

Adhesion in coatings is achieved in a couple of ways. Chemical adhesion which happens when you reapply in the recoat window. Mechanical adhesion when you sand to get an irregular surface profile. Primer/bonders use a variety of tricks to get adhesion. Some soften the original surface, others use wetting agents that affect surface tension and others use nano particles to get into microscopic surface imperfections and lock on.

I would image that Perfection has a primer that might work. There are alternative industrial primers that could work and be far cheaper. XIM 400W NT (be sure to get NT version) will work with urethane topcoats, dries extremely hard, and is formulated to adhere to difficult to adhere to surfaces like glass, fiberglass, and other smooth surfaces. As with any coating, give it at least a week before you subject it to any abuse. Most people confuse dry times with cure times which is when a coating achieves its full mechanical properties.