11/21/2005 (6.5 hours):

Next week I'll be going on vacation. I'm trying to get one wing glassed before I go, so today I prepped the top spar cap channel for glassing (1 hour) and came back to the office late to do the job (5.5 hours). It was quite an ordeal. It has three more layers than the bottom cap, but the channel doesn't APPEAR to be deeper (it is, it's just unnerving).

Worse still, a number of the threads in my spar cap tape had some type of contaminant, and picking them out and replacing them warped a lot of threads. I spent hours getting everything to lay flat and straight, and when I was done, no matter how hard I squeegeed, I still couldn't get all of the fibers to lay below the channel edges. I'll have some sanding work to do once the layup cures. Sigh.

I think in the future that I won't squeegee directly on the spar cap tape. I did this initially to press the fibers into the layers below, and to bring up excess epoxy. The problem is, it shifts the fibers around quite a bit, and makes the job MUCH harder.

It seems like my magic number is 3 - that's how many layers of tape I can successfully wet out at a time. I'll pre-cut a few 5" strips of plastic to lay in the channel. I'll lay down three layers of tape, get the center wet and lay down a bead of epoxy along the channel, then lay down the plastic. I'll squeegee through that, then lift it to lay down the next few layers. I think this will work better and shift the fibers around less. You definitely want to remove excess epoxy as you go. Otherwise it all ends up at the bottom, and you have a hell of a time getting the tape below the edges of the channel.