Hi everyone,
I’ve been commissioned to build a 4′ X 10′ board room table using oak. I would like to avoid using solid wood for the top as I am afraid there would be too much movement and possible cracking. I’m considering using a large sheet of oak plywood skin and solid oak for an edging. Can anyone suggest if this is wise and if so how does one apply the veneer to the substrate.
thanks
Sam
I
Replies
Get the plywood already veneered. You can even get it prefinished. If you have to join sheets, apply banding or solid edging at the joins. Use the lightest sheet you can live with. Make a torsion box for the top. A fraction of the weight and 10 times the stiffness.
Properly designed there is absolutely no reason why a table of that size would crack if it were made out of solid wood. In addition, a solid wood table would be easier to build and would look a more substantial.
John W.
all
I see pros and cons with both methods (solid vs veneer). Can someone offer designs for both or point me where I can find this.
I've done numurous conference tables including a 17 foot table for MTV, and I think you're on the right track with pre-veneered tops, particularly over MDF. The reason is for dead flatness, less work. None of my clients ever really left the checkbook open, so I would opt for veneer also to keep your labor to a minimum.
One cool option to do, is to get the length you need by adding a decorative margin of the same veneered MDF oak to the ends and sides. Grain should be at a 45° angle to the main middle section, where long grain meets long grain at the corners of the table, and bookmatched at centers. This way you use the lower cost 4x8 (plain sliced, top grade, not rotary) sheet stock for the whole table and avoid veneering yourself, avoid ordering 10 foot sheets and paying the premium as well as shipping, etc.
If you edge glue the MDF, use polyurethane glue or wood epoxy (prewetted), cuz PVA wood glue will swell the joint, and creep under finish. Use biscuits to align dead flush.
Boat tops with long arc sides are coolest table design to use, and I definitely ditto the comment on torsion-box construction. You can get cardboard honeycomb for the core too, but I like to rip strips of 1/2" ply at 4" o.c., and use 1/2" MDF top and 1/2" ply bottom for 3" thick top. PL Premium polyurethane construction adhesive is the best for torsion box glue - fills any minor gaps, and bonds best to ply edges than any other glue.
Do you know the taped miter trick for corner gluing pedestal bases? Fast method for pedestal bases.
"The furniture designer is an architect." - Maurice DuFrenes (French Art Deco furniture designer, contemporary of Ruhlmann)
http://www.pbase.com/dr_dichro http://www.johnblazydesigns.com
How in the world is a 200 pound solid top easier to build than a 75 pound torsion box? The solid might not check (with a big emphasis on the might), but it will not want to stay flat. It will need several stretchers to keep it somewhat flat. Matching the lumber is a big pain. Sanding and planing is even worse. So far as visual appearance of being substantial, no difference at all. That just depends on the design.
This is a paying job. You do it to make a profit. It has to work on the first shot with no callback. Got a 10-foot vacuum table? No? buy full-length 10-foot pre-veneered skins. 1/4 MDF . Build the torsion box with 1/4 luan skins, glued and stapled. Don't forget solid blocking where the legs attach. Glue the finish skins on top. The skirts or edging will NOT match the top. Pick a design that contrasts. MAke sure you have a nice clean flat 10-foot bench. If not, build that first.
Hint: Make sure the 10-foot top will fit in their elevator and through doors and halls FIRST. If not, it has to be a 2-piece top.
Bob,
True, a hollow core top will be somewhat lighter in weight, but at 4 foot by 10 foot in size, no matter what the design is, the top will be challenging to make and deliver.
Checking and warping aren't that hard to avoid, the causes and techniques to prevent these problems have been known for centuries and are well covered in many books. The tables surface won't be glass smooth like a veneered table but it will stay flat overall and feel very nice under the hand in a way that veneer can't duplicate.
Working alone, A cabinetmaker skilled in working in solid wood could make a top that size, ready for a finish in two days, three days if he was taking it really slow and easy. He would need a good source for properly dried wood, but most areas have a few good hardwood suppliers. Last year, starting from rough, less than prime wood supplied by the customer, I made a 4' by 8' top, 2 inches thick, in eight hours and it was fun. And while it was heavy, the two of us lifted it into the back of his truck without help.
The entire process for fabricating a solid wood top is simple, you square up the stock and glue it together. You would need a good, properly tuned, jointer and thickness planer and the edges would probably have to fine tuned the with hand planes, but the work is relatively simple and relaxed with the right tools. If the gluing is done properly, hand scraping and light sanding of the glued up panel shouldn't take more than two or three hours to yield a finish ready surface.
Building a torsion box is fairly straight forward, but attaching a 4 foot by 10 foot face on both sides isn't that easy and absolutely requires helpers at the critical moments. Then you have to make up 28 feet of edge treatment and get it to fit very nicely along the edge of that veneered top. Mistakes aren't supposed to happen, but there is no room for error with the veneer, one gouge or sand through of the 1/128 inch thick surface and you start over again from zero.
Again mistakes aren't supposed to happen but a veneered top will be far more vulnerable to damage during delivery and later once it is in use.
I delivered an oak podium to a corporate boardroom a few years ago and somehow the front panel was badly gouged after it had been in use for a few months. If the panel had been veneered I would have had to take the piece back to my shop and install a new panel. Fortunately the piece was built from solid wood, I only had to scrape down the damaged area and refinish it in an hour on the premises, which made the customer, and me, quite happy.
Your way works and can yield beautiful results, but I suggested solid wood because it is in many ways technically less demanding and I got the impression from the original question that the poster didn't have a lot of wood working experience on pieces of this scale.
John W.
Boy, those two cases are the most well articulated cases for either construction method. I'd still go for pre-veneered panels (1/2" face skin), because to do solid would require quartersawn (costly) to avoid the warping, or to use narrow rips. Still a nice, quickly built table, but I'm a sucker for bookmatched veneers.
Torsion box, even of this size does not require two people, and is not near as difficult as John makes it sound. I've done many before, and it was always a relaxing, one person process. Polyurethane glue makes it easy too. However, John is right on about how sand-through of the veneer can ruin your day bigtime. Squaring a 3" thick ply edge to accept the edging is no fun either, but I'm used to it. Good points on damage too, John.
Would you do 8/4 (or 12/4) without build up strips at edges and ends, or use 4/4 with buildups?
Definitely check accessibility with a ten foot table. I've heard of long tables riding on the roofs of the elevators - sounds hairy.
"The furniture designer is an architect." - Maurice DuFrenes (French Art Deco furniture designer, contemporary of Ruhlmann)
http://www.pbase.com/dr_dichro http://www.johnblazydesigns.com
Dr. D.,
My first thought about making that size top out of solid wood would be to use carefully matched built up edges on a panel made from 4/4 stock. It is obviously extra work to build up the edge, but the savings in material and reduced weight would compensate for the extra time. It would also hide some of the understructure and reduce the forces created by wood movement.
Building a torsion box is easy but it seems that attaching a 4'x10' veneered sheet must present some technical challenges, glue-ups almost always do. Just curious, how would you glue, position and clamp down a top of this size?
John W.
, how would you glue, position and clamp down a top of this size?
2-layer top and bottm skins. Glue and staple 1/4 luaun to the ribs. Let dry. Roll on urethane glue, or 1/16 notched trowel. Put a couple clamps along one edge of the work table. Stand up the top skin on its edge. Tilt it to 45 degrees and hold it up with a scrap that has a slot at one end. The clamps keep it from sliding onto the floor. Go around the other side, take off the prop and lay the skin down. Slide as necessary. I use zip-lock baggies as sandbags. Make up 50 with a couple pounds of sand in each. Start tossing them on from the center out. Let it dry a day. Trim with a down-cut spiral bit to avoid tearing the veneer. Can do it the same way with thicker single skins, just no staples and harder to trim. CAn do both skins the same day by laying down one, glueing it and tipping the core down, then the top skin. Whole core only weighs the same as a sheet of 1/2" plywood.
Thanks for the explanation, I'm surprised that the small sandbag approach gives a good bond, I'll be sure to need the technique someday. You don't at least run a roller over the sheet before you throw on the bags?
John W.
Hello,
Very interesting discussion...I've learned lots...
I need to quote on a walnut boardroom table asap.
I'm looking for a Canadian source for 3 veneered walnut tabletops- 6' x 8'.
Does anyone have a source?
Thanks!!
silver
I'll weigh in at this point. A custom made board room table should make a statement about the company who ordered it. Off the shelf veneered plywood says "cheap" because it looks like plywood. On the otherhand, a well made solid wood table will last forever and imparts the same message, "we're here to stay". A veneered, edge banded table with exquisite pattern matched veneers also says good things about the table's owner, but is a helluva lot more work. I'd go with 6/4 QSWO from sequeential flitches with lots of flake for the top. A four board top with 2 book matched sides would look bitchen. If two halves don't match well an ebony strip can be used to good effect. If you had to use 5, slipmatching would probably look best. I'd skip breadboard ends unless the client wants them and if so explain they will seldom be flush. The big challenge is to joint the edges on big long boards. Since I don't have a giant jointer I do them on my TS with a sled and sweeten them up with a #7 Bailey. Flattening the glued up top is very easy if you have access to a widebelt sander. There's a cabinet shop in my neighborhood that has a 4 footer and charges $25/hr, 1 hr min and it takes about 15 minutes to do an 8 footer. W/o a widebelt european 4x24 beltsander with a sanding frame does a very good job. I say european because they seem to be the only ones that make the sanding frames. Mine's a Bosch. Let us know which you way you go with this.
John O'Connell - JKO Handcrafted Woodworking
Life is tough. It's tougher if you're stupid - John Wayne
We build lots of large tables, this would be one of our smallest. Theoretically, the solid top is the simplest to make, especially if you have a widebelt sander. And the wood movement can be easily accomodated with the design of the base. However, you are setting yourself up for possible wood movement problems down the road, particularly if the client does not have humidity control in the boardroom, or if they decide to put a piece of glass on the top of the table to keep it in good shape. A solid top table WILL warp severely if glass is put on one side (ask me how I know this!) In order for you to get a good answer, we need to know a little bit more about the job:
1. Is the client a friend of yours looking for a cheap table, or is this table meant to impress? If it is supposed to be impressive, then you should probably decline this job as I don't think you are ready for it, based on your questions here. (No offense, but some kinds of projects are a large leap forward from the common level of woodworking skill. This is one of them.) If the client is just looking for a big table, then the preveneered ply/solid edge would be OK
2. How do you intend to move this table around? I would build it in at least two pieces, joined with KV Tite-joint connectors. You will need to be able to make a perfectly straight cut in the middle of the table, or else it will look terrible. If you build it in one piece, particularly a solid top, it is going to be extremely difficult to handle.
3. How do you intend to finish this table?
4. How much money is involved?
Good Luck!
Paul Downs
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