Building Logs

Glassing the sides to the top.

Posted by Paul

This relentless summer heat continues. I started at 8am (I was up at 7am but dawdled around much to my later regret). I have the top completely glued to the sides and it is ready to sand. It only takes a day to set in summer. Once it is sanded smooth and rounded the glass will go on without weak spots caused by sharp turn or edges and just as importantly no voids for air bubbles to form under the glass. Sanding the outside joins was easy enough although hard to reach leaning either over onto the roof or from on the roof (I got up onto the roof for the first time today) leaning over the curve trying to be sure not to fall off.

Once the outside was sanded smooth enough to glass I gave it a clean off with a damp towel. I was not concerned about any moisture under the glass because I still had a lot of work to do inside sanding so there was no chance that it would not be dry by the time I would be ready to glass. Then I moved to sanding the inside joins. It is amazing how heavy hand power tools get when they have to be used above your head. I could barely lift the larger grinder for more than 30 seconds at a time, and even the flat orbital 1/3 sheet sander felt heavy. I used a large disc grinder because the radius of the disc closely matched the curve of the join from inside so I could use the edge to sand out the filler and fine finish with the flat orbital.

I found I had a bit of a hollow on the port side in the middle of the curve for about 300mm that creates and ugly step of about 10mm deep after sanding. It is smooth and gradual so as to allow glassing but will need to be bogged to fair it out. I may fair it with bog then glass again just to be sure the bog can never come out. The slight imperfection is the only problem I encountered in the entire roof fitting job so in itself is not such a concern, is not structurally weaker and will fair out, but it is worth noting for 2 reasons. Firstly it is the direct result of laziness due to heat exhaustion. I could see that the roof needed to be pushed down from outside and could not figure out a way to do it. I would need to make a very long brace to the side wall perhaps or the roof of the shed? A very difficult task. I found that over just 300mm I could not get blocks screwed through the roof into other blocks to apply enough force to pull it down, perhaps what I should have done is cut that piece of roof out for about 30mm wide by the 300mm long curved section and refill it at the correct height. But the heat had made me impatient to finish the job so I accepted a little less than I should have thinking that I could fix it with bog. This is the second point. Every builder would have heard the term, “nothing a little bog wont hide, or fix”. The problem with this for composite builders is we have gone to the trouble and expense of using a high tech material that is lighter for the same strength as other materials only to be flippant about the weight of bog. We have it drummed into to us from other builders, designers material suppliers etc to keep the weight down. Yesterday I let heat and tiredness overrule the voice in my head telling me it was not quite right. Fortunately for me I have been fairly diligent and have got a fairly good fit of the entire roof so the amount of bog overall will not be too great. But it is a timely warning that correct preparation is much better than correction.

So with all the joins sanded (including a section of side to deck join) I was ready to glass. By now it was around 11am and starting to get really hot. Again. I measured the glass length I would need and set up a plastic sheet on the side bench. I decided to use 200mm and 150mm glass instead of the proscribed 200mm and 150mm glass tapes, just to be sure I completely covered the joins well although I stuck to the 200 and 150 inside as the joins were closer. I wet out a length of each and set about putting the 250mm onto the boat in the usual way we tape long lengths, the wet out length is rolled up then rolled out on the job. Then the 200mm tape over it centred on it and by now I could feel the tape getting really hot in my hand. Its open time was running out, I really had to hustle. I had sweat dripping into my eyes and it was sauna like up on deck but I got the second tape on and the air bubbles out. I decided to peel ply the tapes more to use the peel ply to ensure that I got no air bubbles because the entire roof needs to be sanded before I bog it so the width of tapes not having to be sanded is not much of a help, although it does all help, and I guess it is one less area I don’t risk sanding through the glass. I decided because I barely made it to get both tapes down I would only wet one tape at a time on the other side. It took a little longer but at least I was not under as much time pressure.

side to top glassed portside to top glassed port 1side to top glassed sbside to top glassed sb 1

Once the outside was done I continued on with the inside taping. This time gravity was against me but I didn’t have too much trouble ensuring that the tapes were completely stuck on, at 1 point I did have one tape start to peel off again but I quickly caught it before it had come off more than a meter and re attach it. Once all air bubble are out there is enough surface tension suction to ensure the tapes stay on and in this heat it does not take long for them to start to gel off. The second tape has the advantage of the wet tape below it to help it stick and sometimes I brush resin onto the job first and wait for it to tack off a little to help with adhesion but that was not necessary today. I also taped a section on each side (of the boat) of the side to deck joins. I still have gaps to fill on the deck to side curves in the middle of the curves. Once that is done I can cove the outside of the join and glass that. I may cove and glass wet on wet to save having to sand that cove. It will be a larger radius cove than usual.

I had to have many breaks due to the heat, if I had started at 7am instead of 8am I may well have finished in 4 hours instead of 5. One of the things I did amuse myself with whilst having a drink break was to put a sunroof on the roof to see where I would mount it. To my surprise, the curve of the roof (most car roofs are curved so aftermarket sunroofs are also curved) almost exactly matches the curve of the sunroof if mounted about 300mm from the edge of the roof. I was intending to mount the sunroofs as far outboard as I could maybe only 100mm from the edge but as you get closer to the edge the curve increases and will mean having to build the side up to meet the roof and will not look as fair as it does 300mm in so I am certain to fit them there.

I did get done what I set out to today but I was absolutely exhausted after 5 hours of sweating. I then went grocery shopping with Jo as I had promised we would do together today but I had old man shuffle as I pushed the trolley around or more accurately leant over the trolley as I shuffled around. I then collapsed to the couch watching the cricket for the afternoon.

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