Sunday, September 11, 2011

Be Prepared - 42 Hours

Not much exciting happening the past few days, just draw, cut, glue and repeat. But one important lesson did pop up sometime this week. Always double check the orientation of parts that are laid out to be assembled.
The way we work is to lay out the parts to be laminated together, in this case a keel side and the backbone assembly. Then using Raka 127 epoxy resin with the 606 slow hardener we coat the raw wood of the surfaces to be joined. These surfaces are allowed to set for several minutes while we’re typically doing some other last minute task. Then a thickened epoxy mixture is made up and applied to one surface, the keel piece in this case, and that is then flipped over and clamped to it’s mate, in this case to the backbone.
The problem was that somewhere between the initial decision to glue these two parts together and laying them out and the actual applying of epoxy the keel side got flipped! So I applied epoxy and thickened epoxy what is the outside of the keel not the side to be glued to the backbone. This wasn’t noticed until we were ready to pick it up and flip it in to place, Doh!! 
Luckily we had used the 606 slow hardener with the thickened epoxy and it was an easy matter to scrape it off the keel and apply it to the backbone. Then we just flipped the keel over on the workbench, the workbench is covered with plastic that the epoxy will not stick to, and proceeded to apply plain epoxy to the keel. So in the end we just ended up with one keel side with an early coat of epoxy.
Had we been using the 610 fast hardener things may have been different. When mixing just a quarter cup of that it will start to kick, get hot, in the cup in under 10 minutes with a room temperature of about 65 deg F.

Oh, and the picture has nothing to do with the described event, it just shows the interesting scrap pieces of wood that are generated when 8 copies of the rudder are cut out.

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