By February 2013, it was time to take the next step and get the cabin top covered with new fiber reinforced plastic. The plan was to put one layer of 1708 biaxial fiberglass over the salon roof hatch repair area, then cover the whole cabin top with a single monolithic layer of the same material. Modern biaxial cloth is a huge technological advance over anything that was available in the late 1960s, offering much greater strength than even heavy woven roving with a much, much lighter final layup. Since the original Roamer 46 cabin top FRP layup was only three layers of light woven boat cloth (and very resin heavy in spots), this new FRP skin should greatly strengthen the roof. No more collapsed hatches from broken roof frames and 3″ fiberglass tape!
On the big day, my fairing crew boss showed up with a surprise (albeit an expensive one): several yards of biaxial Kevlar cloth. He felt this would be the best option for the first layer over the salon roof hatch repair and for the base of the windshield.
I’ve looked at the original spec sheet for these Chris Craft Roamers, and I can say for an absolute fact that “bullet-proof cabin top” was NOT a factory option. But it will be on mine! 😉
The repair was done in lightweight boat cloth and it was dry in spots. There was another repair to the starboard side but not as extensive as this. We decided the best approach would be to apply a new layer of FRP from the bow seat, over the windshield base support area, and all the way to the dashboard.
The helm station door frames still needs to be built and tied into the cabin top, but I haven’t had time to do it yet. I’ve also been looking for a competent carpenter who can do the work but thus far haven’t had any luck. I’ve found competent carpenters who are too busy to focus on a big project. Incompetent ones, needless to say, are everywhere and ready to work…but no thank you.
Random oriented mat on one side stitched to 90* bi-axial on the other.
My Wiss 1225 scissors are pretty good, but that Kevlar fabric put up a good fight. It’s incredibly tough stuff, and we haven’t even saturated it in epoxy yet!
We’ll brush and squeegee wood flour-thickened epoxy into all of the blisters I documented while stripping the cabin top. Doing so fills the blisters and gives the FRP layer a solid surface to bond to. If we just ‘glassed over the blisters, we’d get air bubbles under the new FRP.
* Boatamalan: portmanteau indicating highly skilled boat workers of Central American origin. 😉
Ruis, the head Boatamalan, tells me that they use Kevlar and 1708 fiberglass bi-axial on the bottoms of Weaver Boatworks’ multi-million dollar sportfish boats. Apparently, the manager at Weaver took a sample of their bottom layup to the shooting range and set it up as a target. Later analysis showed that .308 rounds would penetrate two layers of fiberglass, but they could not pass through one layer of 1708 over Kevlar. The ‘glass layer was damaged, but the Kevlar stopped the bullet.
OK, I’ve been informed that “bullet-proof” is the incorrect term, since a modern .50 caliber machine gun might (with some effort) breach the fabric. Bullet-resistant Chris Craft is apparently the preferred term.
That’s still pretty freakin’ kewl! 😉
Unfortunately, I was unable to take pictures after this because I was the official epoxy mixer. We went through 20 half-gallon batches that day.
After putting the 1708 biaxial layer down all the way to the bow seat, we cut more Kevlar and 1708 and applied it to the base of the windshield. By the time that was done, the epoxy in the hatch area had set up.
Time for fairing compound!
After the FRP layer was done, I continued mixing resin for the fairing compound.
Since we’re using the same epoxy for the FRP layup as the fairing compound, chemical compatibility is perfect and so is the chemical bond between layers. When we sand the fairing compound layer and apply more compound to the low spots, we won’t break the fibers that give the FRP layer strength. This approach is also less labor intensive than applying the FRP then sanding it to apply fairing compound.
That was a very long day…and it happened only two weeks ago.
Next up on our 1969 Chris Craft Roamer 46 Refit: The Helm Station/Dashboard.