Join Date: Nov 2007
Location: The Land of Jersey
Hey Pete, If it's just a few here and there that need to be ripped, I just draw the line on both sides of the jamb and freehand (no fence) rip it halfway then flip the board towards me and finish the rip leaving the pencil line on the board, then clean it up to the pencil line with a stiff sanding block and some heavy grit sandpaper. They come out perfect and only take a few minutes to do. Of course it takes a steady hand and an awareness of the safety risk involved, but we've done it this way for years and the it's the fastest easiest way. I won't do this with anything shorter than 36" because of the lack of material to hold onto. If you need this done to all of the jambs then I could see your need for something more on-site production oriented.
I can feel the safety police shaking their finger at me already.
Truth is on a house trim job, I work a bit differently than I do when I'm in my shop, but still apply the same basic rule...if it doesn't feel comfortable, I don't do it.