I found your awesome site through Google. I could use some advice!
My commuter bike finally died after years of service. I have a road bike, but it's not suited to the city streets where I ride. While pondering buying a new commuter bike, my neighbors threw out a 10 speed converted to a commuter - the problem with it was that it was rusty and the tires are in bad shape and cracked. I assumed the inner tubes would be the same. So I purchased new tubes and tires, and replaced the front ones. The rear wheel nut (on the right) is completely seized. I have tried moving it with an adjustable wrench, but it keeps slipping. I don't want to ruin the nut, and I put some oil on it with the hope it might seep inside and help me loosen it up a bit. Any advice? I was bummed out because I was looking forward to tuning it up and driving it in to work tomorrow.
Congrats on finding a "new" bike. Did you try tightening the left nut securely before trying to loosen the right nut? Sometimes you have to work back and forth like that, tightening one and trying the other and/or vice versa. If that doesn't work, you could try heating the nut, too, with a propane torch, or any flame. Heat will expand the metal and should help loosen the nut.
One of these steps should help you get it off. Have fun fixing up that bike!