I will soon be reaching the stage of the centreplate case replacement where I need to make a cardboard template for the sides. However, before that can happen I need to chisel away some of the old case side that is between the fore and aft blocks and the keel.This is tedious as it requires me to kneel or squat in an awkward and cramped position working with a sharp 6mm chisel being careful not to go too far and cut away too much.
Not something I enjoy much so I decided to do something else first.
First task is to remove the top strengthening piece from the removed case side. I wedged the old and slightly less old pieces of plywood apart with a screwdriver and was able to pull the two pieces apart by hand. This is the result. The lower piece has the batten I want to retain with some of the original plywood attached and you can clearly see just how badly deteriorated it is. This did make it quite tiring to remove the plywood since it had no mechanical strength and only came away in small pieces. Still, after some time I had most of it removed.
This is the batten showing the outer face and the removed plywood flakes.
And this is the other side with some of the damaged plywood still attached. I decided that trying to get this off with a chisel was far to difficult and thus I was doing it the wrong way.
So, I removed the remains of the brass screws…
…and planed the rest off, the work of just a few minutes. I really should have just removed the screws and then used the planer instead of messing around with a chisel.
The result is very good.
I still need to remove the diagonal brace, seen here, it’s the longer piece in the middle and this might be a little more difficult than the first piece as it has a rounded edge making the planing of the side opposite to the rounded side a little more problematic. Still, it will be easier than trying to get the plywood off by hand.
Following this successful task I turned my attention to the centreplate case. The bit highlighted in red is the forward block and the bit highlighted in green is the bit I have chiseled out! There’s not a lot of room in there.
I turned my attention to the portlights after that. One side of each light was cleaned with Isopropyl Alcohol and a strip of Butyl tape applied making sure to cover the holes.
The light was then placed on the cabin side and six 5mm flanged bolts pushed through the holes in the perspex, the tape and the holes in the cabin side, but left protruding.
Some more Butyl tape was wound around each bolt just below the flange and the bolt then pushed in as far as I could by hand..
On the inside a washer and a self-locking nut were put onto the bolt and tightened up by holding a hex key on the outside and using a nut driver on the inside. That metal bar you can see outside is a hex key in the bolt on the outside being stopped from moving by a lead block so that I could tighten the nut up in the inside. Both forward lights were done with this lead block method but the two aft ones were close enough to the hatch for me to reach inside and outside at the same time, making the job a lot easier.
The tightening is done in stages so as not to crack the perspex. The bolts were tightened in opposite pairs so as to prevent bending to much. The nuts were not tightened up as far as possible as it is cold outside at the moment and the Butyl tape is not very flexible as a result. The nuts were done up about 60% of the way and then left. This will allow the tape to be compressed slowly an in a couple of days I’ll tighten then up to about 75% and then to 90% a couple of days after that. That will be tight enough to make a very good seal but to tight enough to squeeze all the tape out of the seal. This tape never goes hard, so leaving a bit unsquashed means that if there is ever a leak then I can tighten up the nuts a little to make a better seal. Any tape the squeezes out of the joint will be removed by scoring it around with a sharp knife and pulling the excess away
Here are the two starboard port lights. It would have been better if the Butyl tape were brown, but it isn’t so the portlights will stand out a lot more than they did before. It won’t affect the sailing performance, just the aesthetics and, being male, that doesn’t bother me much.
Time for a cup of tea.