Got a 8 ton digger I need to get some shoes off. I guess they are about 3/4" bolts and been on for 10 years.
I have totally off grid solar and only a 3kw inverter (5kw peak) So not going to be able to run a very big compressor. I would prefer a battery one anyway but not sure they will have enough grunt to knock em free,
How many nm of torque should I aim for? Easy to get a air one that is 1500 nm but the battery ones seem to be a lot less.
I don't have a precise reply but if we go back to basics, an impact driver is a hand tool fitted to the nut. You strike the outer end of the driver with a heavy lump hammer and the force is converted into a torque which forces the nut to turn. Brute force but it works. Air compressors are nice but essentially this is a mechanical problem.
The other thought is to firstly apply heat to each nut - one at a time. Immediately use the impact wrench. The heat will expand the nut and break any rust bond. This is what mechanics and engineers do. I use a butane torch I bought from a hardware shop. This type of torch uses butane cartridges like for camping stoves.
Apart from that my dear old Dad on the farm years ago often had to tackle rusted seized nuts. Ultimately it came down to a cold chisel to split the nut, or if there was room, a hacksaw cut. These days an angle grinder with a cutting blade would do the job.