This probably belongs in the RUST forum,My 2 cents, anyway. I've never had much luck with heating rusted bolts. Mapp gas is hotter than Propane and available in most hardware stores. My procedure is soak the nuts, bolts with Kroil, PBlaster, whatever let it sit for a day or two. I have found Kroil a bit better. If the penetrating oil doesn't work, a breaker bar, big wrench, either breaks it loose or breaks it. Then drill and tap, grind the top of the shaft flat, center punch as close as possible to center. Start with a small drill and increase in size always trying to stay close to center. If I need to try and save it, or the options are not a choice or I have a bunch. I'll get out the Oxy/acetylene and with a drag tip try and cut the nut off. I've gotten pretty good at it, most of the time I can get the nut with out hurting the bolt. In most cases if something is that rusted, it's history, what ever is going to get done faster. The only hesitation is saving what material is around it. A drill and tap set is a lot cheaper than Oxy/acetylene torch. May be that was more than 2 cents :-^)
Larry
68 C20 327 daily driver
63 C20 292 Camper truck
65 C10 ? Custom Cab AC,PB,PS,$flasher
