So I had my first real newbie screw-up last night while putting on the last side. Checked all my panels with a straight edge and, good! no more than 1/16 off each other, almost perfect. Then applied PL with a steady hand, a nice thick bead along each panel edge. I even finished off the tube of PL right at the last inch of the last panel... perfect! Finally, I carefully lowered the side squarely on top, looks great! Time to screw it down and call it good. But when I drove that first screw down on my mark line for an inner panel, wait... what? That sure didn't feel right. looking down the throat of the horn I see it missed it's mark by inches. OH NO!!!!! I have my mark lines on the wrong side of the board!!!
Panic attack! what to do, what to do!?!?! I ended up pulling it back off, wiping all the PL off. what a friggin mess. PL everywhere. marked my lines on the correct side, and then started over. To top it all off, somehow while tightening the screws down, the side shifted slightly so it isn't square. It's off on about 1/16-1/8 at either corner. ARRGGGG! oh well. not enough for it to fail I hope. just enough to piss me off even more. no pics. too embarrassing.

Note to other newbies: check your lines and make sure your stuff fits correctly before you use PL especially on the last side! DOH!