It's been a while, but I have gotten some good advice here.

https://flic.kr/p/2kgvcD4

I'm recycling some 1.5" thick butcher-block style table top material that I got for free. The piece was a weird shape, something like 15" x 84". I wanted to make it about 41"x26" for a small coffee table, although I haven't decided yet what to put underneath the top.

I cut it in half lengthwise and then ripped it down with a circular saw and straightedge. It was difficult due to a not-great saw, a not-great blade and my not-great skills. I kind of butchered it, even doing the cut in three passes, but I was expecting that. I "jointed" the edge with a router, a straightedge and a straight bit, which worked well.

Anyway, despite a heck of a lot of long-grain surface to glue, I decided to use dowels to fasten the two pieces together. I figured that - if nothing else - they would make the alignment easy and nothing would slip when I put the clamps on. It worked well, but were the dowels a waste of time, at least for strength?