So, on to the bottom for the chest. Based on the size lumber I had, I decided to run my boards for the bottom from front to back and rather than glue up a panel, I'm just going to let them float individually in the grooves of the sides of the chest. To keep gaps from opening up all the way through as the wood moves with the seasons, I chose to use
shiplap joints where the edges of the board meet. These joints are pretty simple to execute, and with minimal tools. All I used was my marking gauge and a 1" square rabbet plane.
To start, I set my gauge to the desired setting, in this case 1/2", and ran a gauge line down the edge of the bottom boards, on top on one side, on bottom on the other side. Then I reset the gauge to 3/8", half the thickness of my boards, and ran these gauge lines on the edge of the 3/4" thickness. To start the rabbet, take your rabbet plane and tilt it toward the inside of the board so that just the corner of the iron rides in the gauge line made earlier on the face of the board, using the finger tips of your left hand to ride against the edge of the board and act as a fence. A couple of passes like this establishes a shoulder for the rabbet plane to ride against and the plane can now be straightened to 90* and run down the edge of the board until you reach the 3/8" depth gauge line. And that's pretty much all there is to it.
I have to admit, this is really the first time I've used a rabbet plane in a project and it's a great tool. Mine is one I happened to find on eBay about a month ago. When it came in I just inspected it and set it aside, not having an immediate use for it. Well last night I found a use. Sharpened the blade on a few different grits of oil stones for 5 minutes or so and that was all it took to have a wonderfully functioning plane. Nice tight mouth and all. This turned out to be a great find and I will be keeping my eyes open for more. The square blade rabbet planes are much tougher to find than the skewed, but I've heard they are better, and the performance of this one gave me no reason to doubt these claims.
Next step, a couple passes on all the pieces with the smooth plane and then some assembly.