With the stiffenes in place, I fitted the forward bottom skin. After making 100% certain everything was centered, I maked the stiffener location on the skin. I removed the skin, layed out the rivet pattern and then pre-drilled the skin. I fitted the skin back in place and drilled the skin to the firewall, then the stiffeners. I then back-drilled the forward skin to the carrythrough and the mid bottom skins. After all that, I fitted the right side skin back in place and drilled the overlap at the lower longeron. There are some areas left undrilled; these are for the gear towers and tank attache. Eventually there will be bolts in these areas.
Since I have heard of issues with smoking rivets on this bottom skin, I made the rivet spacing 1" rather than 1.25".
