Spot-marked the holes in the spar caps this morning by drilling through the spar web with a #40 drill bit. Note that you don't drill all the way through the cap. The only purpose is to mark the location of the holes in the web. While I was tooled-up, I went ahead and marked both sets of spar caps. I'll probably do the same for the drilling operation too. That should make construction go more quickly after I get the first spar finished. The only drawback to this is that if you make a mistake, you have a high likelyhood of making it twice, so I'm being very careful to verify absolutely everything before doing something irreversable. If you're sweating making your own spars like I was, don't. It's completely do-able.