This one won't be very long, nor will there be a whole lot of photos. Glue just isn't that glamorous when one comes right down to it. Rough sanding and slot cutting are also included in this post toward the end.
On the original tabletop, I used dowels and didn't allow for expansion and contraction of the wood (my complete and total "bad"). After considerable research, I discovered most cracking comes when trying to place boards perpendicular to each other (breadboard ends with no expansion slots). Virtually no cracking occurs when all the boards are parallel to each other. So, this time around, no dowels will be used. Nor will there be any breadboard ends.
The only glitch, if one wants to call it that, in this entire glue-up process is trying to align the tops of every single plank with the one next to it as glue is applied. The thickness planer took them all down to the same thickness....after all, isn't that what a thickness planer should do? But when planks have a slight bow in them and others don't, there's gotta be a way to get them all flush and keep them that way as the glue is curing.
Enter my "solution":
First, only two planks at a time adding the next one only after the first two have cured so there won't be any additional warping. This takes a lot longer, but the results are well worth the patience needed.
Once the clamps were in place, the next step was to place angle iron on top and bottom to get the most pressure possible for the best alignment. Worked like a charm, too. As you can see, C-clamps were used because they have a pretty deep throat depth.
I also broke down and bought another set of pipe clamps (Harbor Freight has some good ones on the cheap).
The last part of this process was the most difficult because the table edges were left "live edge", and they slanted down and inward which made clamping them somewhat more difficult, but not impossible. The same angle iron process for alignment was used here, too. Only this time, I had to use a couple of other slide clamps for the angle iron to complement the C-clamps.
This thing is actually starting to look like a tabletop. To be honest, I had my doubts when I started all of this, but things seem to be coming together pretty well after all.
Now for the rough sanding using my 4x24 belt sander. It didn't take long to smooth things out in preparation for the random orbital sander that did the finish sanding (220 grit). I also used an angle grinder with sanding flap wheel to shape the ends of the table followed by a once over with inflatable sanding drum for the finish sanding....use your imagination cuz I didn't get any photos of that part of the process.
On to routing out the slots to accommodate the supports. This one was a little disconcerting because the overall thickness of this slab is about 1/4" less than the original. I knew the slots had to be routed to the same depth as the original, but I also knew I'd have to figure out something else for screws to attach those supports on the underside. Otherwise, the original screws were too long and might go all the way through....not something I want to have happen!
Set the correct depth on the router.
Used a spade bit instead of trying to plunge into the wood to get a starter hole.
Used some really heavy gauge square steel tubing as a guide in order to eliminate any "drift".
Off to the races!!
Once the slots were routed out, some fill work needed to be done on some cracks and knots. I'd generated a whole lot of very fine red sawdust already, so why not use that to accent the fill work?
CA glue in the bottom of the void followed by a pretty thick layer of sawdust did the trick!
And there ya have it....all glued up and nowhere to go. Well, not really because now I'm "going" to finish this project with an epoxy/resin seal coat followed by a flood pour and hope the client likes the finished project.