Coving, Fairing

Coving All Finished

Posted by Paul

Queens Birthday long weekend was a productive one. I have finished all of the coving and glassing of the hull panels and bulkheads and the temporary bulkheads have been removed. Today I managed to glass the last section, the middle section between BH4 and BH5 the main living area, known as the saloon. It is also the widest section. As it was the last bulkhead taping, I wanted to take photos to illustrate leaving slack on the outside of the turn to be sure it adheres to the panel without lifting but unfortunately I had a problem with the camera and no time (with wet tapes to finish and resin on my gloves) to fix it, so it will have to wait until the second (starboard) hull.

I now have to (probably tomorrow) trim the overhanging glass as it is sharp and must be trimmed ready to turn the hull, but before that, as readers will no doubt know by now, I have to sand the rest of the bog fair, then high build (thick sand-able paint) a few times sanding progressively finer until I am satisfied that the boat is fair to the middle of the main hull panels. No more excuses, so as soon as I get back from Melbourne (yes I am going again tomorrow night for the rest of the week) next weekend I will be onto it. So tomorrow I will trim the glass overhang with a router and generally clean up ready for the sanding.

A couple of tips I have picked up whilst doing the taping, are if you have any loose strands of glass at the edges (and you will get lots of them) resist the temptation to pull at them, they run the whole length of the tape and cause more mess trying to remove them than just letting them be, and it will also pull the wet glass away from the panel so you will need to re apply it. You can easily snap them off when the resin is set although you may get them caught in the glass roller so then you may have to cut them, but use scissors rather than pull them.

The other tip is that you have a lot more time to work with resin and filler in winter than you do in summer. You are lucky to get 20 minutes in summer when the temperature is over 25 degree (and usually closer to 30+) but in winter when it is around mid teens you have nearer to an hour before resin will be unworkable and the coving filler is even longer. Today I used some left over filler that I had mixed more than 2 hours earlier. This means you can safely mix larger batches of resin or filler and be sure to be able to use it all before it sets or goes off. A few times in summer we had much smaller batches go exothermic on us and almost spontaneously combust, but there was never a hint of that over the past couple of months.

I have been trying to get a 1 meter 3M sanding board but they are hard to find and they are super expensive (no one stocks them anymore and the price has recently gone up). They are made of a lightweight composite material and have hookit on the sanding face for attaching the sand paper. They are made in either flexible or rigid. I have decided that for now, I cant justify $160 on a sanding board so I am going to attempt to make one. I am going to use an offcut of Duflex as it is also lightweight and over 1 meter should not be too flexible but may have just a little give in it which may not be a bad thing. I will contact or resin some hookit to one face and attach handles to the other and see how it works. It is really important that it is as light as it can be as it is hard enough work without having to use a heavy board all day. I have bought 2 $6 trowels for handles and will resin and glass them onto the Duflex. On the other side (the sanding side) I will first glue down a layer of dense foam padding which I hope to get from Clark rubber. Then onto that I will glue the hookit and I should have a working torture board. More on this when I finish it and test it.

making the tortureboard

One final thought. I have spoken to some builders that weigh their glass and their resin to ensure the correct ratio of resin to glass (I think it is 50:50). I don’t bother to do this for 3 reasons and 1 of them is laziness. The other 2 are good reasons I think. Firstly I have been shown (by Brett Schionning) how to apply the correct amount of resin to correctly wet out glass (and if I use the wombat, it does that for me) and I also believe that us amateurs seem to err on the side of using too much resin if anything. We are taught to constantly be vigilant to watch the weight of the boat, in other words don’t use too much resin, bog, etc (too much resin does not make the boat stronger, just heavier, so long as you have not used to little). The other reason which I feel is far more compelling is, say I have weighed the correct amount of resin for the cloth I need for the job and I get to near the end of the wet out and I run out of resin (meaning I have put too much resin onto the glass already wet), what are my options? To not wet out the rest of the glass so that I don’t go over my allowed resin content? I have already done that on the rest of the job anyway and I can’t leave glass un-resined. So there is really no point to me in weighing the resin and the glass so long as I am sure that the glass is getting enough resin and that all the glass is wet. I am fairly confident I am getting this right.

All in all I have really enjoyed the weekend. It was great to be working solidly on the boat and to feel like I was getting something done for a change.

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