Lamination question

[Zhent]

I started building the laminated top to a workbench without figuring out what the rest of it will look like - assuming that until I can confirm the design and understand how the joinery works I can always use it on a pair of sawhorses. I've got a few mini-glue ups done, to varying degrees of 'acceptable', but I have a few basic questions I'm hoping someone can answer. I've poked around trying to find answers myself and I think I know what I should do, but without having done it before my knowledge is theoretical at best.

Lamination Question

In the above photo are a bunch of my 2x6 x 8's that I plan on using for a benchtop - this is the bottom half of them. That top board wont lay flat on the other four. The half of the board out of the shot is flat down the length of the boards, it just curls up at this end. I think to get this end to come down, I need to plane from roughly where that clamp is down the board, and hopefully the point they rest flat will keep getting closer to the end?

Thanks!

Edit: I think this is in the wrong place, but I am only using hand tools?!

[cwarner]

Are those bottom four boards glued together in the picture?  Those four look like they lay nice and flat together.  If they are already glued up, they form a nice straight and stiff beam.  When you clamp a board with a bow to that beam, the bowed piece will be forced to conform to the first four due to its mass and stiffness compared to the single bowed board.  No planing needed. 

If those first four are not glued up, I would do that first to create that nice straight beam to start from, then add any pieces that may have a bow in them.

[Alan S]

Another thing to keep in mind is that the base of your bench will need stock that is shorter.  While the top board in your photo is not too bad, I would tend to use the most warped boards in shorter pieces.  There is much less thickness lost in planing them straight, and you may not even need to do that.

[hbmcc]

Your work looks good to this point! And, nice shelving system!

Framing lumber responds well to 16 and 20d persuasion. And, heavy clamps are costly. (You may never need the clamps after the bench build. That Irwin is a TinkerToy.) I would predrill and use about 25) 3-inch heavy duty deck screws to glue everything in the lamination down. It's just slow as you may not like 5 pounds of steel buried in the top, so each lam. needs to be de-screwed after the glue sets. You will want about a half to full gallon of Titebond for the bench job. They have one type, I, II, III(?) that is slower setting. Doug fir requires a corded impact driver/drill to penetrate the deck screws. 

1. Glue the lams on a level base. I assume, as the others, that you have glued the first 4 boards.  If not, keep the first boards as square as possible on your level base. Gluing will be like chasing cats. Hold rough flattening until after the slab is glued. You can push bent boards flat during glue up so don't need to prep everything first. (Those little clamps on the wall will work for that.)

2. Keep the flattest, cleanest, vertical grain board for the the facing piece. What you lean into. If you want square dogs, cut its partner before gluing. Note, some people can get snarky and cut mortises and tenons before glue-up. You will be busy enough just gluing.

I like your thinking. I still use sawhorses. But, a 5"+ thick x 11"/12" x 5-foot glu-lam is about 70 pounds. You could invest in a Harbor Freight two-wheel dolly. You could also dump the glue-up top idea and buy a second hand glu-lam, like I eventually did.

[Zhent]

Thanks everyone. The first four are glued up already - I made 3 sets of 4, but decided that I wanted one more board to bring the top almost to 20"D.

Full Benchtop

That's a great point about the legs, stretchers, etc. I know I have more 2x6's in the basement, I will swap some of those over and see if anything ended up straighter than this one.