Winston wrote:
The proper answer is 'buy or borrow a table saw with a dado blade'.

However, I don't want to.

I want to use my plunge router to place a 3-1/2" square lap joint
about 3/4" deep on the ends of several pressure treated 2x4s.
(snip)
What would SuperWoodworker do?


SuperWoodworker might double up 1x4s rather than cutting lap joints in
2x4s, depending on the application.