Monday, May 2, 2011

Off the table

I left the board on the rocker table for another 12 hours to let the resin completely cure. The board came off the perspex no problems at all ( one question answered). Overall it came out very nicely!

It weighted in at 1.85kg!!! Which at first seemed to light and I was worried that I had squeezed out too much resin as I was expecting it to come in at around 2.1kg again. However, I added a tab to BoardOff to calculate the exact area and hence the weight of the laminate and it turns out that the area of baord is just 0.47m^2 and so the laminate all up should have been around 1kg for a 50% fibre fraction and not the 1.3-1.4 kg I estamated as this included the excess glass and resin.


So here's some photos
Fresh off the rocker table

The bottom is ultra smooth having been pressed on the pristine perspex table surface.

Target concave of 7mm came in at 6mm but I suspect it may relax a bit more over the next few days. Look at that shine!!!

 
Before working the rails back. The extra rocker is very noticeable
.
Overall I'm very happy with how it came out. I reckon the first board was about a 4/10 and I'd rate this one about 7/10. Its hard to get close up shots with the iPhone so I can't show the details of the things that don't look so flash but the main thing that I still haven't been able to crack is getting rid of tiny air bubbles.

The air bubble problem is only marginally less than on the first board despite working the resin a hell of a lot more this time. There aren't the large areas of trapped air that I had last time but the pin hole sized bubbles are just as pervasive on both the top and the bottom.

I got a tip from a friend who is an experience boat builder who said to do another coat of resin with a paint brush and dab the resin into the holes. I think I'll do that on both the top and the bottom and then re-bag it.

The peel ply wicked away a fair bit of resin but leaves a very clear imprint of the weave ( which I had been told). Apparently this is great if you are putting another layer on because the surface area is dramatically increased. However it also means that there is no gloss on the finish. So I might kill two birds with one stone and put another think layer of epoxy on top and vacuum bag it with the vac film directly on the board so that it will come off glossy.

2 comments :

  1. Nice indeed! Light as well! Matt, I don't recall, from where is the white bottom? Is it Klegcell?
    D.

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  2. Hey Dean. Thanks very much.

    The white bottom is just white epoxy based pigment mixed with the epoxy. It adds just 5% to the volume of resin but it should keen the bottom looking good after a few scratches.

    Cheers
    Matt

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