With the salon hatch installed and covered with two perpendicular layers of 1/4″ marine plywood, the next step was to cover the entire cabin top with fiberglass. When the project began, I assumed I’d be able to sand off the 20 year-old enamel paint job that was cracking off of the cabin top, then prime, final sand and paint. But as we sanded through the paint layers, it became obvious that the old gelcoat was degraded to the point that stripping all of it off was necessary. As the gelcoat came off it became readily apparent that being thorough cost a little bit more this time around, but if we hadn’t stripped the gelcoat the new paint job would have failed within the first year or two of service.
There is no practical way to make the Roamer 46 cabin top out of a single monolithic FRP structure. So multiple parts of the top are made in separate molds, then bonded together using heavy fiberglass roving on the inside. On the outside, Chris Craft only filled the seams with fairing compound, which eventually cracks. Grinding out the cracks and putting in more fairing compound is a band-aid approach that previous owners used on our Roamer–they all predictably failed. The end result is broken paint down the length of the cabin top.
Incidentally, based on what I see on my 1968 Commander 42, Chris Craft used the same technique on all of their FRP hulls and cabin tops: heavy roving holds everything very solidly together on the inside, but they didn’t use even a light fiberglass boat cloth to cover the exterior seams. Every exposed seam eventually cracks. On the flip side, the perfectly fair gelcoat that covered all of the finished parts was highly praised by both the media and the market back in the late ’60s. There would have been no practical way to accomplish this with a layer of fiberglass covering both sides of every seam. This perfectly exemplifies the longstanding observation that boats are all about the compromises.
But since we’re taking a somewhat modern approach to this refit and will use Awlgrip paint rather than gelcoat as the top coat, we can make improvements to the original built that would not have been practical on Chris Craft’s high volume production line.
This shot shows why all of the gelcoat had to come off.
Region 1 is where the enamel paint from a repaint decades ago remained. It was all pretty much cracked and dead, though tenaciously sticking to the gelcoat.
Region 2 (between the red and blue lines) is the original gelcoat. It’s got some cracks in it, but the bigger issue is the little pock marks and tiny bumps in the gelcoat. Some of these pock marks indicate where the gelcoat has popped right off the FRP below. The tiny bumps, though, appear to be little blisters. The latter are the sneaky little buggers.
Region 3 shows where there were no pock marks in the gelcoat. After sanding the gelcoat off, we found the FRP surface to be in perfect condition–ready for primer, a light sanding and paint.
Region 4 shows what happened to the FRP surface when the gelcoat bond failed. Presumably, water got in and through a likely combination of chemical reactions and freeze-thaw cycles, the surface of the FRP was attacked. Region 4 is literally covered with pits wherever there was a pock mark in the gelcoat. If we had simply sanded and filled the visible pits and smoothed out the tiny blisters in the gelcoat, the new paint would likely have popped off of the blisters (or at least cracked) on the first hot day.
The dust relocator got a serious workout that day, as did our Tyvek suits. But once we were done, the cabin top offered a very nice surface on which to apply a new layer of modern epoxy and fiberglass.
The next step in an earlier iteration of the plan was to only fiberglass over the salon hatch hole in the cabin top. But with everything we discovered on the FRP skin, I decided the best approach was a new monolithic layer over the whole thing. In light of the really poor FRP layup at the base of the windshield, I felt it was best to remove the windshield entirely and run the new glass all the way up onto the flat surface that the windshield frame rests on. Little did I know what I’d find next.
“Just needs engines and a paint job…” HA! Yeah, RIGHT! lol
Next up in our 1969 Chris Craft Roamer 46 Refit: Removing the windshield.