I own a log cabin in Australia (and there is not much resource over here). Its old – built in the 30’s from a hard wood gum. The logs have turned black and grey in parts, expect they were once treated with creasote. We want to bring these back so we can stain them. However don’t have corn cob blasting here. We’ve got soda or dry ice blasting – would you recommend any of these?
I would recommend sand blasting. You will need to protect the windows with plywood or duct tape tar paper over them. Be VERY careful not to cut wires or anything else that could be damaged from the sand blasting. Sounds like you will have to grind the logs with a 50 grit disc after blasting to finish cleaning them.After all of this work be sure to use a good quality log home stain like Perma Chink.