To Prime or Not to Prime?

(Written fall of 2007 - Posted Summer 2008)

The process of coating the outside of the boat with epoxy was complete and the prospect of actually applying paint was at hand. I had the outside of the hull looking nice and I wondered whether using a primer coat was really necessary. I used Google, I emailed CLC, and I read the really, really small print on the Interlux paint cans at West Marine. One builder even indicated the epoxy served as the primer and the finish coat could go right over the epoxy. All things considered I decided I would use a primer coat of Interlux Pre-Kote before the Interlux Brightside Polyurethane.

Next, do I brush, do I roll? I decided to roll. Of course the surfaces between the skid rails and the first side panel would have to be brushed but that shouldn’t be a problem. Do I apply the paint thin or do I go for a thicker coat? One of the reasons for putting this primer on is to allow for some sanding to smooth out irregularities in the shape of the hull, so let’s go for a thicker application (this in spite of the fact there was very little I needed to “hide” with a filling primer coat).

And then the “it’s my first time using this paint” monster reared its ugly head. Rolling this paint allowed me to lay a generous coat on the hull but when I got to the areas where I need to use a brush there was no way I could match the coverage of the rolled portions. Brushing the paint resulted in a much thinner coat. But hey, this is the primer coat. I can feather the brushed area into the rolled area by sanding carefully, right? Keep painting.

OK, I’ve got some sanding work ahead of me but at least I primed the hull. That’s the important thing. How long do I have to wait? I think the can said 16 hours but I waited a good 24 hours. Let’s try a small spot to see if it’s dried. Nope. The sandpaper is gumming up. I’ll wait another day.

It’s a new day but this 220 grit sandpaper is still gumming up. I’ll try something coarser like I did with the epoxy. Nope, the 100 grit gums up too. It’s been humid, let’s wait another day.

One more try, maybe even a coarser grit. Oooh, that’s not working well at all. The paint is globbing up like cottage cheese. No way I can possibly smooth that mess out. What about over here? Nope, this section of the hull is just as bad.

Note: At this point seismographs in several parts of the country recorded the shock waves from the explosion that occurred when I realized that all of that paint was going to be removed from my boat.

You know, if there was a problem with humidity and the drying time of this paint there should be a warning on the label. If you are supposed to apply it in thin layers then put that in the instructions. I had many hours and an extra coat of epoxy invested in that hull and the prospect of removing this gummy paint mess was,…well,…kids might have access to this blog so I will forego the language that adequately describes my emotions. To say I was furious is putting it mildly. While Interlux products come very highly recommended, and there are many boat builders who have obviously used the Pre-Kote product with success, I WILL NEVER APPLY THAT PRIMER TO ANYTHING.

This was the hottest part of August and my enthusiasm for sanding was at its lowest point. So it took me several days to accomplish the paint removal. Of course it also took many, many sheets of sandpaper and everything in my garage was coated with a thick layer of white paint dust. It took a day just to clean up the garage.

The sanding was accomplished with 60 and 80 grit sandpaper. As a result there were numerous areas where the epoxy coat was removed with the paint. That meant buying more epoxy, coating and recoating the bare areas, and the sanding that goes along with it.

I painted the bottom with white Interlux Brightside Polyurethane. The first coat left a bit of a blotchy coverage and there were a few runs. I made a small sanding block and put a layer of thick felt on it to produce a surface that would follow the subtle contours of the hull. The second coat covered very nicely and dried to a beautiful finish. There was only one set of runs and they will remain as evidence of my novice boat building status.

(My apologies for the lack of pictures of my painting/sanding episode.)

Here's how the boat looked at the end of August:

The summer was quickly drawing to a close and the primer experience had put a damper on my enthusiasm. The main goal now was to get the cars back in the garage before frost and snow aggravated the level of inconvenience my project had created for our parking situation.
I finished coating the bunks I had made for the trailer with epoxy and covered them with automobile carpet I had purchased from Menards. The boat was loaded on the trailer. After rearranging my storage shelves into a tall tower to create some floor space the boat was tucked into the front corner of the garage.

The finish work will have to wait until spring.