Friday, July 17, 2009
Today my dad came down and helped mix epoxy… Though I had him wait… as I had to do some prep work. A lot… before getting the bulkhead in.
I used the angle iron to hold things in place. One about level, the other running up hill, in the event that my plywood had any bow to it or wanted to float at an angle…
If you look real close I have a 5/8ths thick wood block supporting the weight. I used that to draw lines on the hull by laying a sharpie on the plywood on each side. I then pulled the ply back out, and unrolled my ¾ inch thick weather stripping down the middle.
With the weather stripping in place, I epoxy coated the edge of the plywood and dropped it in place. I popped my wooden block just barely under one side of the wood and clamped everything square.
I then put two 20 and 3/8ths long 2x4’s down the passageway and squared up the opening till they hung with no support in the gap.
I took a straight edge for the last time to see that it was perfect… and we started mixing thickened epoxy. I wrestled with the idea of using milled glass in the mix, but decided that if things get to flexing enough that its needed I have bigger problems… so cabosil.
It was a new experience for me, putting a fillet on a surface tighter than 90 degrees, on a curve… with a pipe in the middle. Normally I use a piece of 1/4 th inch polyethylene cut on the bandsaw to whatever is needed… raked at an angle smaller than 90 on the wall side, and dead flat on the floor side, 4 to 6 inches long. Held at an angle less than 90 in the direction of travel it cleans up for you as you go… nothing really to sand. This time I made a little tool out of luan, and broke it into shorter and shorter lengths. The front side was 3 fingers wide, with my ring finger doing the job of cleaning up the pass as it went up hill… The aft side worked best about 2 inches long.
With the fillets in on both sides, I started glassing the aft side of the bulkhead with a 4 inch tab (8 inches wide piece of glass) and discovered that glass doesn’t lay smoothly around the radius of my sewer pipe. I’ll have to cut a dart on each side for it to lay over.
I discovered however… that my fillet on the aft side wasn’t quite large enough to cover the outermost edge of foam. I thought it was smooth, but it wasn’t… making it impossible to wet out without a bubble forming along the corner of the foam… So I took the 64 inch long strip back off, and tossed it on the scrap pile. After that act… which always feels satisfying… I added more meat to the fillet by rotating the angle against the hull allowing more goooo to pass under the fillet stick.
(Wipes sweat off brow…)
Casualties: Burned up shop vac.
Innovations: 3M Paint and rust remover, looks like a black spider web of really abrasive stuff that you chuck in a drill… Works beautifully to sand the inside of fillets, and inside corners of the cabin top. It has enough guts to clear out fiberglass too, which I discovered trying to use it to remove paint from the hull… whilst it smoothed out the roving. I’m running it in a right angle drill. Sweeet tool of the day.
Finally toasted my 36 grit flap disk. Swapped it out for an 80… Don’t think it is going to last as long as the cutting speed reduced quickly from new. Though the reduction probably seemed more severe, as the new 36 grit flap disk acts about like a plasma cutter to steel…
Zach - My arms are getting tired of grinding overhead... Need another cheeseburger to continue.