It has been a while since I did a general update on my project on MaJic Carpet. Things are progressing well now and I am very near to starting to glass up the mid-section of the hull. The new core has been installed and the existing balsa has been fully dried. Now I am doing some basic fairing and filling of the divots I created when I got too aggressive with the pneumatic chisel. This tool makes it very easy to shear the old skin off or to remove core. The trick is to learn to not pry with it and only use it to shear. That is easier said then done because the wet balsa has little or no structural rigidity. Amazingly though when dried out it becomes quite stiff again. The 2nd part to improve success is to cut or score smaller sections, I found 4" x 4" to work very well. When I had larger sections there was a tendency to bury the chisel too far and in the process of pulling the bit out I would damage the balsa. I got the impact chisel online and then also tracked down a wider bit at 1-1/2" wide (about $65 together). I actually rounded the bit over on the grinder to get rid of the sharp cutting edge. While I have a large compressor right next to my work area I think I could run this tool easily on either of my small portable compressors. It doesn't need much in the way of CFM or air pressure to do this kind of work. Very short bursts move the chisel quickly and easily, at least in my case.
The other little breakthrough I had was learning that the first vacuum pump I bought works great for bedding the core in. I think a shop vac might also work ok for this, but I didn't test it. This little Gast R1 can run all day under vacuum load and not heat up. The advantage to using a high volume pump is that you can seal your film off with blue painters tape or similar (which is very inexpensive compared to the high tack vacuum tape). The small vacuum leaks between the balsa blocks are not a problem with this higher volume air flow and you still get more than adequate compression of the balsa into the bedding. In one area I actually did some glass work both on the inside and the outside of the inner skin before installing the new core. This inner skin was never very thick or strong in the first place and the removal of the core thinned it out too much. The chopped strand mat just sort of fuzzed away with the removal of the core.
The hardest part of this work by far is removing the rest of the old polyester resin from the end grain balsa. This is some quality time with the 4" grinder and 36 grit working overhead. A full face mask is required for this bit of insanity. Once that old resin is gone the balsa for the most part dries really quickly. There have been a couple of stubborn spots that needed a little heat to get fully dried right next to the solid part near the centerline. I also rechecked that solid glass section just a bit ago and see that it still shows being wet even after being exposed to a fair amount of heat from all the drying I have been doing. I think when I get the glass back on I will get the other high vacuum pump out and apply heat and a high vacuum to these areas to suck whatever juice is remaining in the solid section out. No way do I want moisture invading my newly dried balsa.
I really have to believe that having epoxy on the inside of the inner skin in the bilge from my previous work on the sole and having a very thick new outer skin of epoxy resin, this boat should be as sealed up as good as is possible. There will be no drilling of new holes on the inner side of this hull. I will bond blocks and then screw into them. Hopefully no one will ever do this project on this boat again.
Electrical work has been on hold while the weather is good. I did get out on my racing cat recently and then promptly cracked a lug out on the hull that hold the main beam, so am doing some glass work to fix that too. The fantasy is to get this J30 hull fully dried out and glassed back in so we can do something way more fun like spray paint the hull before it gets too cool this fall. I think that could actually happen at the current pace of work.
Here is a short video that is already dated. The work has moved well beyond, but I haven't shot any new video.
