Joining two pieces of oak plywood without fancy equipment?

[Mike Hartigan]

I'm finally putting the top on my bar (in the final weeks of a ten+ year project). I'm using 3/4" lumber core red oak veneer plywood (a fine looking piece). The bar is 13' long, so it's gonna have a seam. I've done all the cutting and dry fitting and it's good to go. Now I just need to attach the two pieces together. When I butt the two ends together, the seam is barely visible - it disappears enough for my needs, so I think I'm almost home free. I'll probably use a bit of wood putty to fill any imperfections, maybe making the seam even less visible in the process. I'm wondering how I can stabilize the joint so it doesn't crack. What are some techniques for doing this with not much more than average DIY shop tools? Should I put glue in the joint? Should I reinforce it from below? what about clamping? a 13' pipe clamp seems a bit unwieldly and a 13' bar clamp doesn't qualify as 'average DIY shop tools' ;). Any suggestions would surely be appreciated.

-Mike

[Old guy]

Sounds like you are off to a good start.

I'd cut a 3/4" plywood batten about 12" wide and as long as the length of the joint (or slightly less if visibility is a problem), glue it to each piece of the top, and fasten it with screws. I'd glue the ends of the plywood to each other, but I'd use epoxy, just because I think it grabs end grain wood better than carpenter's glue. (Probably an urban legend, but I think that). And finally I'd arrange for some sort of support directly under the joint, so when some drunken (well very, very happy) friend stands on the bar, his weight doesn't deflect the top, and lever the two top pieces apart.

If you don't immobilize the joint, any filler you put in there will crack and work its way out. It may anyhow, but you did all you could.

You did cut the top pieces so that the grain figure is similar across the joint, I'm sure.

This advice is guaranteed for the next 4 minutes.

Old Guy

[bridgerfafc]

get a spline into the joint. either do it with a biscuit jointer, spacing the biscuits pretty close together or use a router with a wing cutter to make a continuous slot in both ends and fill it with a carefully fitted bit of wood. plywood would be a good choice for the spline, cut from scrap of the same material as the tops if possible.

you can clamp it by attaching temporary blocks a little back from the edge and clamping those. you'll probably want to have them top and bottom, to balance forces so it doesn't buckle. if the ends of the bar are enclosed you may be able to drive them together with wedges.

[Charley]

If you make a spline, be sure to cut the spline so that the grain runs across the joint and not in line with it. I think the biscuit method would be good enough and much easier. You might also consider looking at the countertop fasteners that are available for joining the ready made sections of countertop that are available at the Borgs. To use them you will need to rout some pockets in the underside of both pieces of plywood. You should definately provide additional reinforcement like a vertical panel under the joint area to prevent flexing under even the most extreme load situations.

[Larry W]

I would use a batten or plate below the 2 pieces as you suggested to support the joint and keep any up/down offset between the 2 pieces from developing. Biscuits or a spline could be used as well but since the underside won't be visible the batten would be simpler and probably stronger. The supporting structure will presumably keep the bar top itself from experiencing any flex or bending, correct? (If you have any girls dancing on top all bets are off)

Glue should theoretically help with this joint as every other ply will present long grain to long grain for a good glue bond. As for clamping, you could sandwich each piece between a pair of 2X4s clamped perpendicular to the length of the planks near each end, then apply clamps to the 2X4s.

[SonomaProducts.com]

You will want to use "Draw Bolts"

can get them anywhere they sell counter tops... home depot, etc.

You could use glue if you wanted but not really necessary. I would NOT use putty unless the joint is really bad. Even so, putty is not at all long lasting in a seam type joint. If you need to you could use some silicone or dap type stuff that can take the flex.

[B A R R Y]

My favorite way to deal with situations like this is to incorporate a design feature that incorporates some sort of break. Sometimes, this may involve adding additional breaks to balance the look. The break could be a reveal, hardwood strip, banding, laminate, whatever... depending on the design.

I've never had a problem because movement is allowed.

[RayV]

You can get bolts similar to these at just about any home center or hardware store.

you use these to clamp it together put a wide piece across the joint underneath and screw up into both pieces of plywood at an angle to hold them co-planar and together.

Works for kitchen countertops, should be fine for your purpose. Don't forget to apply finish on the bottom when you are done to help prevent warping.

[wolf28]

biscuits & bench-dogs.

[GROVER]

Mike, Joining plywood edge to edge is a comman job in cabinet shops. A usual technique as Ray V already posted is to use the "Tite Joint" hardware coupled with biscuits for alignment. The February Rockler catalog shows the fastener on page 105( Item number 27037) You can also get a drill guide (Item number 27052) which aligns the mortises for the hardware. Their dedicated drilll bit is next to useless. Its a paddle bit which fails on first usage. Joe G

[wolf28]

Sorry mike its pinch dogs.

[J T]

Mon, Feb 26, 2007, 7:13pm (EST-1) [e-mail] (Mike=A0Hartigan) doth advertise: I'm finally putting the top on my bar (in the final weeks of a ten+ year project). The bar is 13' long, so it's gonna have a seam.

Jeeze, I've geen in real bars with shorter bars. Your mind must be numbed with the booze, just think on it a bit, and all sorts of solutions will pop up in your mind.

Scarf, no rocket science involved. Put a hinged entry at the 8' line, then another small portion of br on t he other side of the entry. Put a coffee machine in the center over t he seam. Make your entry right in the center, with equal bar lengths on each side. Make an inlay at the center, the full width of the bard, nicely taking care of the seam. Paint the whole damn thing, then you won't be able to see the seam. Scatter sand over the whole top, sprinkle some eashells in, cover with a thick coat of bar finish. Cover the whole top with a 6" or so deep tank, cover with thick glass, and have a bar-top aquaram. I'm not sure, but you might even be able to get a strip of beneer long enough to cover the top in one piece. Make a butcher block top.

See? There's all sorts of solutions, if you just use your imagination. Or, you could just ask your wife what she'dlike. Personally I think that unless you're partying every night you won't need a bar that size - a folding bar would do nicely.

I don't drink anymore myself, but if I did, I'd want something concealed, and classier, than a mere bar, say a globe with a folding top to hold bottles, or something along the lines of a drop front desk Or, something ala James Bondish, I'm sure "Q" would have some excellent ideas.

JOAT When in doubt, go to sleep.

- Mully Small

[Tom B]

what about clamping?

Lots of good suggestions already.

If clamping is an issue I've found that nylon rope (about 1/4-3/8") has enough stretch to provide quite a bit of clamping pressure. A couple of loops around the length, cushioned by some twobys at the ends. Use a hunk of wood to tighten like each a tourniquet, tie the hunks down so they don't spin and loosen and you're good. To avoid any "hinging" at the joint, just clamp a couple of 2' cauls (twobys will do, with wax paper under them) lengthwise at the joint 1/3 of the way into the width. Do that first before you apply lengthwise pressure!

Regards.

Tom

[Mike Hartigan]

Great suggestions -- many thanks!

Here's what I've settled on, based on a composite of some of the ideas you've thrown at me.

First of all, I bought a set of four draw bolts from Home Depot for about $2. They're for joining the mitered corners on laminated countertops. This should provide plenty of clamping force for the joint. I'm gonna attach a 12" wide piece of 3/4" plywood batten to the bottom with glue and screws. There'll be a support immediately under this. As for appearance, I'm going to rout 3/4" wide slots and insert maple strips every 24" (to delineate 'place settings' at the bar). I may even get fancy and do a herring-bone inlay if I'm in the mood. With very little fudging, one of these strips will fall directly on the joint :). When that's all sanded and finished, it will look like one beautiful 13' continuous piece of bar top with some detail thrown in strictly to make it interesting!

WRT JT's c> I'm finally putting the top on my bar (in the final weeks of a ten+