More progress this past week. The hardest thing has been trying to figure out the order for doing things. I've avoided grinding and sanding in my garage - I'm doing this in the driveway so the dust doesn't get into everything I own. Thankfully, we've had almost no rain in NY.
A LOT of grinding on the hull - Mastercraft didn't do a great job with the roving, especially on the sides where there were a lot of pockets that held dirt and debris. If I'm going to be foaming the floor, this needs to be smoothed out and sealed. The mat/roving that held the stringers in also had to be ground down to make a flat bed for the new stringer. I made sure I ground at least 8" away from the stringer to give a good surface to bond the new glass to.
Not easy doing all of this work while a stone's throw from the lake...
I got the secondary stringers cut. I bought douglas fir lumber one size too big so I could cut it to the right size - the secondaries could have been cut from 2x6 material, but I would have had to get the bottom cut just right the first time. I used 2x8s and transferred the hull shape to the 2x8 on each side. I cut the "high side" and used an electric planer to make the angle until both lines were removed.
With the stringers lying down, I placed my handy-dandy laser level in rear of the boat at the height of the top of the floor as marked by the old tabbing on the walls. I then placed the stringers and marked out the top of the floor height. I took off 1/2" and then some for the floor and fiberglass thickness and cut a nice straight line. This came out perfect.
The corners of the stringers were then planed and sanded to make them about 1/4" radius so the glass would bend easily.
I got the port stringer bedded in first. I used medium cure epoxy with 1/4" chop, fairing powder and some sawdust. I didn't get enough to completely fill the gaps between the hull and stringer, so another quick batch of fairing was put into a 1 gallon plastic zip-bag with a corner cut off. I used this like an icing bag and filled the edge and a plastic spoon to make a nice 1/4" fillet. Pretty sweet.
While this was curing, the swim platform was removed and repaired- the bottom braces were cracked, not from skiers' weight, but from water pushing up on the platform when the boat comes to a stop.
The port stringer now has 4" cloth tabbing on both sides and a 12" cloth on the inside that wraps over the top. Another 12" will be placed from the outside of the stringer and roving over the top of it all. This will be one layer better than the original Mastercraft layup, so all should be good. The starboard stringer is bedded, ready for glass once I sand the "twigs" sticking out of the bedding.