On Saturday, December 19, 2020 at 12:11:02 AM UTC-5, wrote:
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?

I've used biscuits, dowels and dominoes but don't really recommend them for most flat-panel glue-ups. That said, if your milling is not great (less than flat, straight and square) dowels could maybe provide a bit of insurance. For most panel glue-ups I just set them on the clamps and adjust them a bit with my thumb and forefinger to align. If it's a larger panel I almost always use slightly curved cauls to hold them in alignment a bit while clamping up. I'll also use an f-clamp or two to pull the ends into alignment if necessary. If I'm really struggling with a glue-up it tends to mean I've not done my milling very well. I'm not some neanderthal that scoffs at anything other than rub joints, but wrenching on clamps to pull boards into alignment for gluing is not something I'd encourage. Lastly, if you use biscuits be sure you leave enough trim allowance on the end so you don't cut into your slots. And if you do decide you don't like that panel layout you'll have slots to deal with if you cut it apart.
JP