Dry Fit First Roof Planks

Posted by Paul

There are days when at the end of it you are no closer (or in effect further) to finishing the boat than you were before you started. Unfortunately you just have to roll with them because as sure as the tide you will have them. I had one today. I may have rushed in my excitement of an new phase of the build or because of the unnecessary over caution I had in fixing the bulkhead when I first started the build maybe I over reacted and didn’t take enough care in fitting the roof frames because I have a couple of lows that I have to fix. It could be that these take just half an hour to fix but as they are they will create problems later in fairing so I have to refit at least 3 of them, possibly 4.

I had the all of the provided roof frames attached to the strongback halves last Sunday night and only got time to glue the duracore planks I have left together during the week. I still had to cut and fit 3 more sets of frames the same size as the back set of frames. These frames are the full size of the roof at the rear most bulkhead (BH6 the main doorway bulkhead) and the roof follows that size and shape the rest of the way back over the cockpit so the frames are cut to the same size to achieve this. I cut up what I had left of the bottom halves of the mdf temporary bulkheads (the parts of these are still in the starboard bulkhead as the molds for the curved hull to deck panel. These were only wide enough to make the curved 1/3 edges of the frames and I ran a piece of timber (shaped to the gentle curve) along the top to complete the full size of the frame. I still have to run a torture-board over them to shape out the irregularities of my jig sawing ability!

Once I had these last 3 molds cut I attached them to the strongback frames in place. The cutting and fitting of these last 3 molds took me most of the day. Once they were in place I got the first plank and dry fit it more out of curiosity and excitement at getting to this stage than anything else. The plans say you can plank the roof with full width panels in the middle as they curve very gently across the middle (left to right) 1500mm or so and only curve dramatically fore and aft until you get to the point at the sides where they start to curve more tightly down the sides as well as the forward curve, and at this point narrower planks will be needed. The plans also say you can cut kerfs in the top face of the planks to create the curve. I tried this but found that with the kerf on the top the kerf point became a hard turn not part of a more gentle curve. This creates the need for a lot more bog and a lot more difficult and time consuming fairing job. So I cut more kerfs into the plank turned it over so that the kerfs are now on the inside of the curve and the plank curved much more evenly.

With the first plank on I noticed a dip in the roof between my very last frame and the last of the originally provided frames, so in other words over the cockpit. The dip is about a 10mm deep and about 2 meters wide and long over all. That is a lot of bog to fill (and sand!) not to mention the converse shape on the inside. It appears on first glance that it is just the most rear frame too high but I cant be sure that it isn’t the correct height and the 2 in between too low until I check it properly.

Upon finding that fault I had a closer look at another area I thought looked a little out and sure enough the 2 frames in front of the last of the pre made frames have a hollow on the sides only (not the top) suggesting at first that the frame was not centred but as the hollow is both sides then it must be that I have not fit them the correct distance from the 0 datum (the front of the roof). It could be that I have incorrectly measured the distance between the frames, it is supposed to be 400mm front face to front face but I may have measured 400mm back face to front face on 2 in a row meaning the second one would be about 35mm off where it should be (the thickness of 2 mdf frames) and given that the width of the frame is relevant to where on the roof it is, this would effect the fairness of the sides of the roof.

I did not have time to properly check the frames so I will need to do that next but today (Sunday) I was asked to crew in a race and agreed so no boat work today. My first Sunday off in a long time. I woke early (guilty conscience) and briefly considered a few hours this morning but couldn’t drag myself out of bed, so be it.

So in effect, because I have to re do work already done I have lost an entire weekend. I only mention it because from time to time these things happen and are not cause for concern, they are part of the ups and downs inevitable on a 5 year project.

You May Also Like