Friday, June 17, 2011

Mast

First, it would not be wrong to state that I was a bit disappointed that, after two days at the glazier, after I had been in contact with them several times in advance to make sure everything was planned for and OK, the boat was still untouched. As there are more to be done than the windows, I had to take her back to my garden and I am currently mounting stuff between other tasks.

The weather turned summerish again today, and I did the other side of the mast. The recesses each side of the section is supposed to be filled with UD carbon in order to provide sideways stiffness. Calculations showed that 210 mm^2 of T700 fibres would give slightly less bending when loaded to balance the righting moment of the boat than the specified carbon section with spreaders and diamonds. The section itself was not part of the calculations.

The bottom of the recess was previously covered with a hand lay up of 200 gsm Formax 45/45 fibres. I sanded this down, and a section outside the recess. Then, after preparing all the 11m pieces of fabric and consumables needed (carbon was cut on the firewood saw when still on the roll, NB don't do this at home and make sure to cover EVERY piece of skin when doing it, don't ask me how I know), I did a wet lay up of 6 layers 430gsm Devold T700 UD fibres. Three layers were staggered and tapered above the hounds, hoping for a bit of flex here.


This is 6 layers of 70mm wide UD and then a piece of 150mm wide 45/45 overlapping the section wall.  Covered with peel ply, about to do the final wet out.  Next was release film, bleeder fabric and the vacuum bag, before the big find-the-leaks-game started.  Seems to have lost a picture here, I recall an error message on the phone.  After a couple of rounds around the bag I was able to pull about 0.85 atm, a bit less than the other side, but sufficient to avoid any air or lift off in the laminate.


Then the mast was covered and heat (around 6kW) put on to let it cure over night.  Summerish here means somewhere between 10 and 20 deg Celcius, close to 10 during night.


Earlier today I recieved this picture from Eivind, he had noticed a familiar shape in the hall at NTNU where my daggerboard molds are currently being milled.  Time to start building soon, as it looks.

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