I was drilling the fabric to the carbed airbox snout with a 90 degree air drill with a stubby #30, things slipped and I ended up with the stubby #30 through the quick of my left thumbnail. Luckily I had a pair of pliers handy to back it out as I was temporarily attached the the front of the airplane....

Most everyone has drilled into a finger. I am surprised that there have been a few exit wounds! Hope I don't join that club.

For those that pine after a high-wing RV, just think of what it is like to walk into the trailing edge of a Cessna 182 wing, with the diamond-shaped stiffening voids in the trailing edge. You have to be about 6 ft to get the full effect. Taller and you just get a lump on your forehead. Shorter, and the trailing edge will just brush your hair. With a Cessna 180, the optimum height is probably more like 5'9".

If you are the right height, you get to find out what a V-shaped trench in your scalp feels like. And it is unbelievable how much blood you have in your scalp.

Liver stress..
 

Aside from the described cuts and contusions that are pretty typical in aircraft maintenance, my liver sustained some abuse during the think,ponder and social brainstorming with neighbors who distracted me..the beer fridge was emptying quicker than the rivet bins on all too many occasions! maybe that's why it took me 15 years to build mine..

Injury
 

Does it have to be sustained while building? I've had the usual drilled fingers, smashed fingers and cuts but the one that I'll never forget was a broken leg.
I broke my Tibia and Fibula slipping off an icey step. Ended up with a 12mm titanium pin from knee to ankle. After a couple weeks recovery, doc put me in a boot and I went back i to the factory building tanks.

I've been keeping a tally on the back of my time log for every time I draw blood. I'm somewhere between 5 and 10, but I'm only halfway through the wings...

I'm currently building a 1200 sqft workshop to build my RV in (almost entirely by myself), however, and I've had some good injuries doing that. The title of this is "injuries while building" which doesn't specify airplanes, so I'm counting it. The "best" was right before Christmas, I was attaching the rafters to the ridge beam. I lifted each beam (2" x 8" x 16') into place and against the ridge beam, then used a speed square to square the beam vertically to the ridge. I then blindly reached around the ridge beam with my framing nailer and end nailed the rafter into place. All while standing 12' in the air on a ladder, above the rung you're supposed to stand on.

Well, on one instance I missed the rafter with the nailer and instead hit the framing square that was still in place. The nailer launched the framing square directly at my face at what must have been Mach 2. It hit me directly on the bridge of the nose hard enough that it bent the framing square. So now I'm 12' in the air dangerously high on a ladder, unable to see because my eyes teared up, framing nailer in one hand, the other hand quickly filling with blood. Lucky I didn't fall or break my nose. Then I got to explain my black and blue nose to 100 people over Christmas.

Needless to say I changed my rafter attachment strategy after that.

I own a few nail guns. My 3 inch framing gun manual has the warning, ?do not press nail gun against head and pull trigger.? Now I know why they include that warning.