I am building a simple timber frame from round wood. White pine in the parts that will be exposed to the weather.
I'd like to control the checking so that it is in the wall thickness (which will be light straw clay) rather than on an exposed face. I've come across a few mentions of the technique of sewari to accomplish this - a kerf cut lengthwise along the middle of a face and possibly widened with wedges as drying proceeds to force the checking to mostly happen on that face. That sounds just like what I want to do.
Anyone I've been able to find who is doing this uses a skill saw or somethings similar. The catch is that I work entirely with hand tools. I don't have a way to get electricity to the site, and I wouldn't want to if I could. I presume sewari is older than power tools, so how was it done? How can I cut a deep lengthwise kerf with hand tools? Or does it work to just carefully split the log along a line with an axe or wedges?