I cut the tenons in two parts, as suggested by the popular woodworking video.
A. I cut down the lines. I used my dovetail saw, but I am sure there are many ways to do this, say, even with a tenon saw.
B. I inserted a pattern bit into my router. I cut and planed down a piece which was the exact width of the tongue. This piece was also just slightly thinner than the depth of the shoulder of the tongue.
These dimensions are important for two reasons.
1. Getting the tongue right means the breadboard will fit snuggly
2. Getting the height of the guide piece right means that when I run my router accross the countertop, it will not push the guide around.
I achieved the correct height of the guide by touch testing.
I achieved the correct width by testing for a perfect fit in the grooves of the breadboards (again avoiding #’s)
You can see that I also used a 2nd one of these guides to help me stop my cutting with the handsaw!
I will not go into great detail because the popular woodworking video does such a great job. I am really just following it. But to put it simply.
The base plate sits on the countertop while the bushing of the pattern bit rides against the guide to give a proper depth to the tenon.
The only part i did not show was using the chisel to trim the rounded ends on each tenon.
Also, one of the countertop panels fell off the work bench and split in half, though not along a glue line!
Thank God I could just glue it up.
-- I came, I was conquered, I was born again. ἵνα ὦσιν ἓν