The ABI ports are beautiful heavy cast and polished bronze, but a challenge to install because of the downward-slopping flange, height that allowed no margin for error when placing them, and the two different radii for the top and bottom corners (See October 25 post). My basic plan was to follow the method that worked for the Ta Chiao ports (See November 1 post.), but this one would be a bit trickier.First step was filling part of the old port hole recess to accommodate the shorter ABI port. This time I used the thinner glass fabric rather than heavy roving, which worked out better. Although it required even more (40+) layers, it was easier to handle and allowed more a more precise build-up, which resulted in much less filling and fairing. Cutting as many as six layers of fabric at once sped up the process. Still, it took most of the day Saturday to grind away the old caulk, grind a bevel to receive the new fiberglass, lay up the fiberglass, grind it flush, fill and fair it. In what was left of the day, Scott helped me tighten up the bolts on the leaking doghouse skylight. In the process we discovered that my previous helper hadn't been too good about getting them really tight, and at least one was stripped and not doing anything. I'm optimistic that we will have conquered the leaking skylight.
Once the hole had been filled, I used the template I had made previously to place the new port and mark the locations of the centers for the four corner holes. These four points were critical as they would determine the size and location of the entire cutout. Because of the size of the interior mounting flange and the limited space on the cabin side, I had to get it right.
I used an adjustable bevel gauge to capture the angle of the sloped flange on the port and then set the angle of my drill guide. I used the drill guide to drill pilot holes which in turn guided the hole saws that were too big to use in the guide.
The resulting four holes determined the cutting lines for the jig saw cuts that would connect them and complete the cutout. The top and bottom cuts had to be angled, so I used the bevel gauge again to set the saw blade angle.
Once the angle was set, I screwed some scrap to the cabin side to guide the saw and made the cuts.
But no matter what type of jig is set up, a hand jig saw is not a precision machine tool. The blade is held only at one end, so it tends to flex, especially when cutting at an angle through thick hard material like fiberglass. So I wasn't surprised that one of my cuts was less than perfect. I had anticipated some careful grinding would be required back in October when I made my test panel cut-out. Alternate grinding and trial fitting eventually got the job done. It also turned out that I was about 1/8 of an inch too high in my placement of the cutout, so I had to grind away a bit of glass on an interior stringer where the ceiling meets the cabin wall. Not difficult; just very messy, throwing fiberglass dust everywhere. 
With the cutout completed, I epoxied the exposed edge of the plywood liner and filled the gap between the liner and the fiberglass with epoxy putty. I had hoped to get the port installed and sealed up by the end of day on Sunday, but I was running out of daylight fast. I set up an infrared heat lamp to try to speed up the curing of the epoxy.
I had hoped I could cut and place the butyl tape around the port while the epoxy cured, but it was just too late and the epoxy wasn't curing in time. It would have to wait until the next dry weekend. I had no choice but to temporarily cover up the hole with plastic sheeting and duct tape. I had just enough energy left to clean things up enough to go home and recuperate.
But no matter what type of jig is set up, a hand jig saw is not a precision machine tool. The blade is held only at one end, so it tends to flex, especially when cutting at an angle through thick hard material like fiberglass. So I wasn't surprised that one of my cuts was less than perfect. I had anticipated some careful grinding would be required back in October when I made my test panel cut-out. Alternate grinding and trial fitting eventually got the job done. It also turned out that I was about 1/8 of an inch too high in my placement of the cutout, so I had to grind away a bit of glass on an interior stringer where the ceiling meets the cabin wall. Not difficult; just very messy, throwing fiberglass dust everywhere. With the cutout completed, I epoxied the exposed edge of the plywood liner and filled the gap between the liner and the fiberglass with epoxy putty. I had hoped to get the port installed and sealed up by the end of day on Sunday, but I was running out of daylight fast. I set up an infrared heat lamp to try to speed up the curing of the epoxy.
I had hoped I could cut and place the butyl tape around the port while the epoxy cured, but it was just too late and the epoxy wasn't curing in time. It would have to wait until the next dry weekend. I had no choice but to temporarily cover up the hole with plastic sheeting and duct tape. I had just enough energy left to clean things up enough to go home and recuperate.News flash: The new oil pressure sensor arrived today, so I will hopefully be able to solve my engine instrumentation mystery soon!
On Wednesday I ground the new glass close to flat and flush, using a straight edge to find and mark the high spots. 
I got to wear my new Wes Cravens designed grinding outfit, hoping to mostly avoid the infamous fiberglass itch.
Next followed three cycles of filling the low spots with Microlite putty and fairing it flush and flat with the manual sanding board (torture board). A foot-wide $3 plastic smoothing tool was a great help in applying the putty flat and smooth across the entire area.
The rain predicted for Thursday was delayed, so I was able cut out the holes for the new ports using my big hole saw and new jig saw. As anyone who's done it will tell you, cutting big holes in your boat, even above the waterline, is always traumatic. "Measure twice, cut once" was a mantra I repeated over and over. Careful use of drilling and cutting guides helped it go smoothly.
Cut-outs showed that my laminations were good: no gaps, all the mat layers fully saturated with resin A little grinding to round the inner edges and the ports slid into the new holes perfectly. Whew!! I coated the newly-exposed edges of the plywood interior liner with epoxy so it wouldn't absorb water and rot in the event of (Heaven forbid!) a leak. While I waited for the epoxy to cure, I cut and applied butyl tape to a porthole flange. In addition to the flat cut pieces of butyl around the outer flange, I added a strip around the corner where the inner and outer flanges meet at a 90 degree angle. The theory was that it would squeeze out between the inner flange and the edge of the hole, resulting in a good seal. 
The individual butyl pieces welded to each other nicely, and the excess squeezed out between the flange and the hole as I had hoped. 
Of course some also sqeezed out around the inside mounting flange on the cabin side, but that was easily removed simply by cutting around the flange with sharp knife and lifting off the excess.
At this point, the epoxy around the hole on the shady side still wasn't cured, it was getting late, the rain was coming in, and I was beat-all good reasons to call it a day and head home.
On the other side (the piece that will be screwed on during installation) I mounted a teak grab handle. No, I didn't make it. At twelve bucks (even at Worst Marine), it wasn't worth the time. 
The next morning, after the glue had set, I trimmed the protruding bungs flat using a flushcut saw. 
I find it works better than using the usual chisel method. Even with a sharp chisel and thin cuts, I usually end up with some of the bungs breaking off below the surface. The flushcut saw doesn't scratch the surface and results in the bung trimmed so close to the surface that normal finish sanding is enough to make it perfect. Finally, finish sanding of the post cover pieces, and between-coats sanding of the varnish on the table parts. Last thing Saturday was to apply varnish all around.
With some white plastic caps to cover the protruding nuts and bolts, it will be a pretty clean installation. I cleaned up the week's mess (well, mostly), and called it a good week.