Living in salt country, I've found heat and percussion to be helpful. Hold a soldering iron to the nut for 3-5 minutes, then wail on it with a rubber mallet. Repeat a few times if needed. Usually loosens up the fastener because it dislodges the gunk in the threads.
Living in salt country, I've found heat and percussion to be helpful. Hold a soldering iron to the nut for 3-5 minutes, then wail on it with a rubber mallet. Repeat a few times if needed. Usually loosens up the fastener because it dislodges the gunk in the threads.