It was from twisting and turning my hands inside the hatch bay trying to get the engine's tubing and cables to run underneath the bypass.
The opening for the hatch has some really sharp edges. I had sanded it down a bit, but still pretty sharp. I lost sense of getting cuts when
i was so focus on getting things to where i wanted them to be. Only later after sitting down, only then i realized how many cuts i had received
on the top of the hands, and or forearm from reaching inside sometime.