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I'm not the best mathematician, so I want to run this by real woodworkers:

I need a board of red oak 29 5/8"W x 16'L to make a cabinet top and then stain it.

This is what I'm thinking to make the wood look evenly distributed... If 1x4 is really 3 1/2"W then 7 * 3.5 = 24 1/2"W - which is acceptable for what I am doing.

So I need 7 1x4x16, correct?

What bothers me is having to butt joint & glue 7 boards of expensive wood hoping it all comes out flush and level.

Is there a better way?

EDIT:

I made a typo..."I need a board of red oak 29 5/8"W x 16'L" should have read, "I need a board of red oak 24 5/8"W x 16'L"

Clarification:

The final length is 159 15/16", but local lumbar yard only sells 16' boards. Hence, I plan to glue-up the 16' boards and then cut to size.

  • Even if you have a local source with enough stock of 16' red oak boards to select from I don't think it's practical for the home woodworker to make a panel of this size in one run. The extreme length could make this basically impossible for you to glue up — you're worried about alignment but have you thought about the logistics of glue application, dealing with glue drying while you're still adjusting? What about clamps, if you haven't already worked it out you're in for a bit of a shock about the number you might need! – Graphus Jun 19 '18 at 14:03
  • Hint: this will take more large clamps than I will ever buy O_O – Graphus Jun 19 '18 at 14:06
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Edge gluing is a very popular way to get big panels without needing very wide lumber (which usually comes at a premium price). Your calculations are correct, in that you will need 7 1x4 boards to achieve a 24 1/2" wide panel. You'd need 8 and some extra to get the full 29 5/8".

One option to reduce the number of glue joints you'll need is to use wider boards to start with. 1x6s and 1x8s are usually readily available at the big home centers as well as some hardwood dealers, and would reduce the number of glue joints to 3 or 4.

Another option - and probably something I'd recommend whatever you go with - is to practice on some cheaper boards. Pine is a cheap way to practice glue ups, and that will give you the confidence to proceed with oak. You can take one piece of pine and cut it to 1-2 foot lengths and do a practice glue-up with those. If you really are planning a 16 foot long tabletop (and that wasn't a typo!), you may want to do at least 1 full-length practice glue-up as that long of a joint could present some logistical challenges.

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I don't quite understand how you're getting from 24 1/2" to 29 5/8", but...

Typically when you're gluing up large, thin panels (and at 3/4" thick, 1x stock would be considered thin in a piece this size) you want to have some kind of alignment aids. These typically take two forms, external cauls or internal splines/biscuits/dowels/dominos.

For an external caul you'll want to get multiple sets of two boards that are longer than the width of your final piece. Make sure one edge is as straight as possible (or slightly crowned.) Coat one edge with packing tape or a film finish so that glue will not stick to it. During your glue-up clamp the boards together with the panel between them every foot or so along the workpiece.

The other alternative is to cut matching recesses in the edge of each board and then put something in the recesses to ensure the boards stay aligned. You could do this with a slot cutting bit in a handheld router or with a purpose-built machine like a biscuit joiner or Festool Domino. There are also many different types of dowel guides that you can use to make properly aligned holes with a hand drill.

Either of these methods will ensure the boards are all relatively flush, but I'd still expect to have to do some cleanup work. It's also important to note that at 3/4" thick over 16' the surface will need some kind of underlying support to stay flat. Make sure whatever cabinets or legs you're mounting this to are level and sturdy.

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  • I can't find a rental biscuit joiner. Spline seems like a doable option for me. I read one can use Masonite which might be easy to slide in the groove and glue. I have s router, just need the bit. – Marinaio Jun 20 '18 at 19:18
  • @Marinaio, alignment aids will help get the surface closer to flush but you're focussing on the wrong thing, take note of what I referred to above especially about the number of clamps that are required. While there are other potential issues/pitfalls to be aware of that alone is enough to stop the project in its tracks — do you have 40 or more clamps with >26" capacity?? Even if you were using pine it would still take more than 20! – Graphus Jun 21 '18 at 12:39
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The first thing you will need for this project is a lot of bar clamps capable of spanning the width of the finish panel (29 5/8"). You should plan on clamping the width of the panel at least every 24" so you will need at least eight or nine clamps to spread across the 16' length. Other answers have offered good advise in starting with smaller widths of 2 or three boards at a time and then adding them together. It would be best to elevate the glue panels with 2x4 or 4x4 wood pieces that span the width of the panels above and below every 24" along the panel length to serve as a cross grain clamp to keep all the panel pieces aligned top and bottom. These cross clamps will require a clamp at each side to compress the top and bottom cross grain clamps and hold the panel faces even. If you have eight of those cross grain clamp assemblies this will require 16 more clamps.

In gluing up the actual panel pieces it is not necessary to use biscuits or tenons, but doing so would reduce the need for the cross clamps. On a panel so large, the boards will may have a tendency to warp or twist over the length. Choose your boards with straight grain and make certain that your grain orientation on adjacent panel boards alternates to reduce the tendency for the composite panel to curl. In addition a wood panel that wide will have a tendency to expand and contract seasonally. Make certain the your cabinet will allow for such expansion. (If you want additional advice on how to do so, consider adding another question with a sketch of actual cabinet with the top. There are plenty of experienced woodworkers who can offer guidance on how to address expansion.

Regardless of how careful you are in the glue up there will be the need to plane or sand the top for a uniform surface. As an alternative you might want to consider using a cabinet grade plywood which will significant simply the cabinet assembly process and reduce expansion problems that arise with natural wood panels.

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several ways to do this You can glue up the boards 2 at a time making sure the boards are flush with each other. Once dry glue up two glued up boards, repeat until you have one board. However keeping the boards flush can be troublesome.

Placing something in the joint that keeps the boards registered will make this easier. This is where splines, biscuits, dowels and the Festool Domino (a floating tenon system) are used.

Spline - (requires tablesaw or router)Either saw or route a groove in each board down each interior edge centering the groove on the edge 1/2"-1" deep. Cut plywood strips (thickness of plywood and width of groove should match and plywood is slightly narrower than 2 times the depth of the groove).

Biscuits (requires a biscuit joiner powertool) Dowels (requires a drill and doweling jig or dowel centers)

Dominos (requires Festool Domino machine)

These all create matching holes that the filler is inserted into to reference the edges

These are all variations on a theme

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  • I have a router. Spline seems like a good option for aligning the boards. But if wood isn't exactly 3/4" then won't the spline and hence the aligment be off? You are thinking of a bit like this, correct? Slotting Cutter Router Bit - 2" Dia x 1/16" H x 1/4" Shank – Marinaio Jun 20 '18 at 19:14
  • Yes, a slotting cutter, Though I think 1/16" is too narrow. If the router is run on the top face of each board, the groove will be consistent regardless of the board thickness – Chuck S Jun 20 '18 at 20:49
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I agree with what was said previously, this is a big project.

I thought I would mention another way of aligning/combining the individual pieces. You can give the boards tongue and groove edges with a combination plane or an wooden T & G set, or even a router. That would give you a continuous system of aligning these boards and increase the glue surface. Good luck with the project, I'd like to hear how it goes.

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  • 1
    FYI the increased glue surface area is not of benefit here, edge butt joints are already stronger than needed (i.e. stronger than the wood around them, assuming they're done well). The T&G is therefore only of benefit for alignment purposes, just as dowels, biscuits, Dominos or splines are. – Graphus Jun 21 '18 at 12:16

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