Re: Transom drain plugged
If the big ones (which is preferred IMO so you don't need a bilge pump) I'd drill it out. If you don't have the big bit, maybe a hole and then a grinder.
Since it is a plug, should be able to drill out the center a common 1/2" metal drill bit, which will leave approximately 1/4" around the inside of the hole. then use a de-burring bit to remove more of it, almost but not right to the metal, then a long narrow screwdriver to pry out the remaining material. Once it gets thin against the aluminum it should flack off easily.
Maybe use a small drum sander attachment instead to finish it off.
Or you could us a thin sharp edged file to cut 4 or 5 notches into the material after the hole was drilled, and then try prying out the sectioned plug material.
Be as careful as you can not to cut into the aluminum but it wont be the end of the world if you nick it. It can be smoothed out.
You have had a lot of suggestions, any of which will work. Start with the easiest, least aggressive, and work your way up.
Good luck, have fun, and take back your cold weather.
