2/20/2006
Before doing anything I marked centerlines on everything that made contact with the bottom skin with a nifty edge marker I just bought from Avery.
I drilled both sides of the bottom middle skins to the skeleton. I am glad everything lined because there is no way to adjust anything had there been a problem. I slipped the rear bottom skin under the other skins and drilled it into place. I had read that some folks had experience oil canning. I drilled from the center of F-806 and worked back along the F-819 baggage ribs.. Then I went down each side of F-806 up to where the bend is. Then I went down the longeron about half way to the F-808 bulkhead. I drilled it and continued to work aft along the longeron and doing the same for the next bulkhead. The idea here was to never let the skin be constrained from two or more sides while there were still undrilled holes (?) in between.
I botched a hole in F-808. It looks like a figure-8. Other than that everything turned out well and in alignment.
I ran out of clecos several times. I had to take some off of some areas to put them on others. I have 420 of this size (#40). 500-600 seems to be the right amount but I don't think I am going to order more at this stage.