cabin sides, Roof

Entire cabin on boat.

Posted by Paul

The Sydney heat wave continued this week. I know I mention this a lot but unfortunately I mention it to explain why no work is getting done. But mercifully a cool southerly change swept through on Friday evening so the weekend was a more mild mid 20’s. I needed it. I had the starboard wrap around in place and mostly pulled and pushed (pulled down with screws and blocks, pushed up with braces underneath) so that the shape was correct with no highs or lows that would need bog to fair out.

Getting the panel exactly right is very frustrating and slow progress. The reason it is so frustrating is it is a bit like poking a balloon filled with water. The kerfed panel is a lot like it. If you pull or push on the panel here, it changes shape in there. So you either abandon that move or if you have to keep it you go to fix the new change and that fix job creates yet another movement. And something I have mentioned before, 2 men doing 1 hour can get much more done that 1 guy doing 2. Each adjustment required me to go outside the boat (or inside depending on where I was making the adjustment) and check the panel from aft looking up the side and from forward looking down the side to be sure that I did not have a bulge or valley that would create fairing issues later. With a second worker, the moving is eliminated saving so much time and so much climbing in and out, up and down. My muscles are sore from the work out. And I am going to have to put stairs in the hulls very soon, I am getting tired of climbing into and out of the hulls without them. I get what I call old man bones and shuffle around the house in the evenings feeling like an old man.

So in all it took me about 2 full days to get the first wrap around in place and exactly in place. As the shed started to heat up in mid afternoon I decided that it was too warm to glue the kerfs and that I would get a start on the port side. I found the same problems as on the first side, the roof needed to be trimmed but not as much as the other side. However, sometimes, for me at least, as small trim is harder to achieve than a large trim. I needed to trim 25mm off the side of the cabin roof on the starboard side, but only 5mm on the port side. (it is still a mystery to me how these gaps are so different, given that the roof centreline meets the hull centreline so theoretically the gaps should have been the same but no worries I just deal with it.) It is quite difficult for me to cut just 5mm off with a jigsaw and ironically I got a near perfect fit when trimming 25mm but ended up with a 5mm gap when trimming just 5mm off, so in effect I trimmed 10mm off!

I still found the roof binding here and there. The middle pic shows that I could not get the wrap around to meet the roof as it wrapped around leaving a 25mm gap that I needed to close up. Then I found the point that was causing the panel to push down as it bent around and marked it out. Once this 200mm sections was trimmed about 12mm the gap was gone and the wrap met the roof as it should. Also on the starboard side I noticed that I may have trimmed the bulkhead too much by about 20mm so I under trimmed on the port side (first pic above you can see the mark where I should have trimmed to but didn’t) and it took me about half an hour to realise that it was this that was stopping the wrap from being pulled down all the way. I found just as I was knocking off which was a relief. I hate going home with problems I cant solve.

This morning I did the traditional Sunday morning early start and was up at 6am and got the the shed about 7am. I started first on gluing the kerfs as it was very cool in the shed. I got a halogen light set up in the cabin (it soon warmed up in there!) and got to filling the kerfs with glue, but pushing out on the kerfed panel to open the kerf us then using a wide plastic spatula and a flexible steel spatula to push glue into the kerfs. Doing it this way means the glue mix has to be exactly right, too thick and the glue wont go all the way into the kerf but too runny and gravity will cause application to be a nightmare and very messy and cause it to run out of the kerf. I quickly found the right consistency and got to filling the kerf from the rear forward as I went around. I took a lot more care for the top and bottom 400mm of the kerfs and whilst I filled the middle of the kerfs I was not as careful on this section, as it will be cut out for the windows. It took me about 2 hours to get the kerfs filled and the panel back in place exactly as it was to set.

By this time it was 9.30am so I headed home to bring Jo a fresh coffee for breakfast and to let the sides set a while without me moving about on the boat. When I got back to the shed about 10.30am the glue was starting to harden and I was confident it would not move if I started moving about on the boat. I got to work setting the port wrap around in perfectly in place. I started by removing the peel ply from the inside of the panel between the kerfs (yes I forgot again to remove it before lifting the panel up onto the boat. The I cut the rest of BH5 overhang that I under trimmed. Then I started on the balloon pushing! I may not have mentioned it before but like other flat panels that turn into curved panels, they need a bit of cajoling into place and sometime the pressure needed seems too much but using long strong screws and blocks it eventually groans and creaks down into place. After being held in place for a while it gets a bit of memory for the shape and if you release it and then pull it back down again, it pulls back down much easier.

As with all things I have done on the build, the second time around happens a lot faster. I have a bit better fit on the first one but close enough that gluing the sides on wont be a problem. I will need to use some offcuts on the middle of the curve each side but once the kerfed panels are stiff with glue and glass then gluing and taping them in will be fairly easy. So in other words the hard work on the cabin roof is now done. It took 2 full days to do the first but I was able to get the second side exactly in place in just 1 day. Unfortunately it was mid afternoon (3.30pm) but the time I was ready to put the glue in the kerfs and decided it was getting too warm, and I was pretty tired and sore so I will glue the kerfs tomorrow.

Once both sides are glued I can take the panels off the boat again which will be fairly easy because the panels will be stiff, and sand them and glass them. I probably wont fully glass them as the middles will be cut out for the windows. I will run 400mm tapes top and bottom and where the mullions (braces that run between the windows to help keep the roof up and re-strengthen the structure as the windows weaken it) will be, this will save glass, resin and work. But one thing I did learn is that the cut outs need to be intact (so I may need to glass them later with light cloth) as they are used as molds to hot form the Perspex windows if using hot forming (cold forming is done on the boat by torturing the panel around).

The middle panel is sitting in place, with only a small gap at the top of the port side to fill. I trimmed the starboard side when I should have just turned the panel over but again the gap is only 10mm so it will be easy to fill. I intend to glue and glass the cabin sides on but I wont be gluing the middle front panel on until later so that I can get to the water tanks as I am not ready to run the plumbing just yet.

All in all a good weekends work. The cabin is now on the boat!

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