Need input on creating this laminated coffee table base

[Chris Merriam]

Two quick follow up questions guys:

When laminating the boards together, is it necessary to use 3 layers or would 2 be ok? I'm probably going to use 8/4 stock so ill have plenty of thickness.

And, what's the official name of this bricklaying technique? All my googling returns bent lamination. I'd like to learn more about this style of work.

Thanks!

[Dave Richards]

You could probably get away with 2 layers just fine. There's a plan for a smaller boat similar to the sailoat I built with the keel made that way. It only uses two layers. Three just seems more "right" to me. Especially so if the grain will show. The center layer could even be a little thinner than the other two if you wanted.

Official name? Good question. I've seen the method used for making arches and wagon wheels as well as curved stair rails and other things. A client of mine built a trestle table I designed for him and the legs are built up that way. We've got another one that will include benches with matching legs and he'll build all the legs that way again. In the case of the three layers it's sort of a built up mitered bridle joint. If two, it would be half lap joints.

By the way, when I made the keel for my boat, I shaped one outside layer to the desired shape. Then I glued the other layers to it and used a router with a pattern trimming bit (bearing on the top) to cut as deep as I Could. I flipped it over and used a flush trim bit (bearing on the end) to finish it up. In your case, since you'll need to make several matching ones, you'll probably want to start with a patter but you might find it useful to clean them up the same way.

[Prashun Patel]

I used an article on FWW (requires subscription, unfortunately). Just search 'Federal Card Table'

It's typically used curved table aprons, which can then be veneered to cover the seams to give the appearance of something that's steam bent.

http://www.sawmillcreek.org/showthre...h-Coffee-Table

[Chris Merriam]

Thanks for the replies. There does seem to be something magical about using 3 plys, it would just mean extra resawing, but we're not talking about any significant lengths, so I'll probably do it.

Prashun that's a great table, I read the original post a few months back. I'm really trying to get out of the "everything square" casework look and try the curvy stuff that you do so well.

[Dave Richards]

Chris, it sounds to me as if you're ready to build a boat.

[Prashun Patel]

Chris, thanks. It's easier than it looks. Curved work allows me to mask my joinery imperfections.

One piece of advice: think twice about resawing the 8/4. If you can cheaply get extra 4/4, I'd do it out of that instead. Resawing 8/4 for aesthetic reasons is one thing, but to break it down to make 4/4 is IMVHO a waste of good 8/4, and possibly unnecessary effort.

[Chris Merriam]

Lol, no need for a boat yet! I'd have nothing to do with it other than to mount it on the wall and stare at it.

I started to do some math to figure out my wood needs (I don't keep any on-hand for the most part). The top alone is going to cost me $150, ouch! The 8/4 comes in 8ft lengths, so if I use 63 inches for the top, that leaves maybe 25in or so left over. It's going to take 4 or 5 boards, so I'll have a good bit left over, so that's what I was planning on using to laminate the legs. Honestly, with the small local mill I just found, the difference in cost for 8/4 vs 4/4 walnut is not too much, $3.75 vs $3.25, which seems to be a pretty darn good price. The bigger local place I normally go to wants $5.75 for 4/4 walnut. I will however pick up a couple 4/4 boards to do the arched stretcher. I guess I could save the cutoff 8/4 for some later project, but honestly I just don't like dealing with tons of scrap and oddly sized pieces. I don't ever really build anything small (maybe I should do some boxes) so it just sits in the corner of the shop and stares at me.

[Dave Richards]

Make an accurate SketchUp model of the table and work out the parts you'll need to make the legs. It might be that you could get away with a number of shorter pieces for the inner layer if you make it out of three layers. This would reduce the required width of the stock you'll need for the middle layer. I agree with Prashun about not resawing the 8/4. Save it for something like normal table legs. It's a shame to waste more walnut than you have to.

[Chris Merriam]

Well it's been a few weeks so I thought I'd post a status update and an additional question for the experts.

I pretty much did everything we discussed. Got some 8/4 walnut for the top, and 4/4 for all the other parts. The legs and stretcher ended up being two plies of 4/4, because the rough stock was generously cut, it was really 1.25in thick, and after jointing I got it down to about 7/8 or so. So two layers gave a nice fat leg. I spent a long time in Sketchup and at the workbench trying to figure out how to best glue up the leg stock to provide a smooth grain flow. My end result is just "ok", nothing like Dave's fancy boat steering wheel though. I think the main issue in the end was the available raw walnut I had to work with, and the fact that I didn't buy any extra. I just couldn't afford to be super picky about the stock I bought. Here's some pics of the legs:
IMG_1159.jpgIMG_1162.jpg

I was pretty leery about building the stretcher correctly, but I modeled it in Sketchup and printed out a full size template. Taped all the sheets of paper together and just traced it right on to my blank. I probably should have cut the domino mortises before I finished roughing out the blank, but I managed to make do after the fact. The stretcher-to-leg angle is 60 degrees (+/- a degree), set the domino fence to 60 and went at it. I used two dominoes in the stretcher, an 8x50 and a 6x40. The 6x40 is only in the stretcher for 12mm, the other 28 is in the leg. I cut those last night, crossed my fingers and did a dry fit, came out perfect. Here are the final pics of the stretcher and base:
IMG_1161.jpgIMG_1163.jpgIMG_1164.jpg

So that's where I am today. It's time to build a cleat, attach the legs to the cleat, then attach the cleat to the tabletop. That's where I'm stuck. Can't wrap my head around the best way to attach the legs to the cleat to allow for a strong anti-racking connection. Any advice? Couple points:

1. The tops of the legs are about 2x3 inches square, and they are end grain (ugh)

2. I'm shooting on a max cleat thickness of no more than one inch

3. Current options I'm considering:
a. Dominoes (I can fit two of the largest (8x50) in each leg
b. Hanger bolt bored into the leg and then attached via some method into the cleat. I found a product at tablelegs.com that might do the trick:SP008-leg-hardware-installation-plate.jpg

4. I was basically counting on the stretcher not providing all the racking resistance. But maybe it's stronger than I think?

Thanks for any advice guys! And thanks for getting me this far!

[Prashun Patel]

Wow, looks great!!!
If the cleat is 1" thick, you'll have no problem. If it's a little wider than the leg base, then screw it into the tops of the legs, then screw the bottom of the cleat into the table at it's widest part. Just elongate the holes, and then snug it down.

[Dave Richards]

It looks really good Chris. thanks for the update. I agree with Prashun about the cleats.

[Chris Merriam]

Thanks guys. I guess my worst nightmare is someone bumping/kicking the end of the table and it folds over and collapses, so maybe I was trying to over-engineer it a bit. Any recommendations for leg-to-cleat screw size, length, and count? I can probably fit 2-4 screws per leg, maybe some 3in deck screws? Or maybe a nice thick #10 screw, not sure how long those go though.

[Prashun Patel]

Here's the thing to remember: No matter how beefy you make your base, a wide table top will exert a good amount of torque on your base. While you may get the cleat to stay perfectly snug to the top, the legs may end up rocking a bit on an 'apronless' table like this. To really resist that, you need to cross up the legs with some kind of bracing.

That being said, it has not been my experience that a coffee table requires a deep connection. I've made tables with cleats thinner than 1" and relatively short screws.

I would use 3 screws on each cleat: One in the center of each cleat, screwed tight and two on the ends, tightened through elongated holes. Watch the table for a year and note the movement. If it's severe, shim between the cleat and the top. If you are using furniture pads on the feet, you can do it there too.

If you are feeling ambitious, you can recess the cleat in an elongated mortise in the top. This way, any shims will be invisible.

If you are feeling even more ambitious and your design likes it, you can make your cleat a sliding dovetail in the top, and use a single screw in the center of each cleat.

[Chris Merriam]

Interesting. I was worried about everything below the cleat, while you are concerned with what's above it, lol! Never thought about torque before, and this will be a heavy 63x23 1.5 inch thick top. In addition to the cleat helping keep things flat, I'm also seriously leaning towards breadboard ends as well. Kind of redundant, but I wanted to hide the end grain and add a little detail to the top.

A sliding dovetail cleat, very interesting. Would like to try it but never done a sliding dovetail yet. I'm too scared to try it on this project!

[Jerry Miner]

Chris--- That table is really looking good. I don't think you need to overthink the cleat-to-leg connection. A couple #10 screws would be plenty (hanger bolt won't really do any more for you, IMHO)---1 1/2" penetration into the leg should be enough. Dominoes would work, too, but if it were me, I'd keep it simple with a couple of screws.

Will you be attaching the stretcher to the underside of the top? It will give you lots of racking resistance. I predict a very stout and stable table. Good work!