Gluing Up Panels

Gluing-up-Panels-Completed-panel

Gluing up panels is a must-have skill in woodworking. From table tops to raised panels there are plenty of times you’ll need to glue boards edge to edge.  When you do you want the panel flat, with rock solid glue joints.  Here’s the recipe for making that happen in your shop.

Gluing-up-Panels-Rough-cut-to-length Rough cut to length.  As you crosscut material for the panel leave it 1” – 2” longer than the finished panel needs to be.  When cutting up long boards it’s often easiest to cut them with a jig saw. It’s much easier to accurately joint short boards than long boards, so it pays to get them close to their finished length.

Gluing up panels joint an edge Joint one edge of each board.  The edges must be smooth, straight and square before gluing boards together.  If you don’t own a jointer, or need more info on using a jointer, be sure to see the related stories we’ve listed at the end of this article.

gluing up panels mark jointed edge Mark the cut.  Make a mark near the edge you jointed, on the face of the board that was against the fence.

gluing up panels rip to widthRip to width.  Note that the jointed edge is against the rip fence.  A ripping cut accomplishes a few things for you.

It makes the two edges parallel, which makes clamping easier.  If the boards you’re clamping are wedge-shaped they tend to slide past each other when you apply clamp pressure.  Wedge-shaped boards also result in a funky shaped panel that can be hard to square up later.

Ripping makes the next round of jointing go faster.  If the board has a rough edge it’s faster to straighten it on the table saw than on the jointer.

I shoot for boards that are 4” – 6” wide in my glue ups.  The wider a board is, the more prone it is to cupping. That’ll sure mess up making a flat panel.  If you want to use a 12” wide board it may seem counter intuitive but what you need to do is cut it down the middle, and then incorporate the two narrower pieces in the glue up.

Your edge to edge glue up should be 1”-2” wider than what is required for the finished panel.

joint the second edge Joint the sawn edge.  Note the position of the pencil mark from the first jointer pass.  The face that was against the fence on the first cut is away from the fence on the second cut.  Mark the second edge, making the mark near the jointed edge and on the face that was against the fence.  For more info on why it’s important to alternate faces against the fence check out the sidebar at the end of this story.

checking the joint Check your joints. Lay the boards on a flat surface and slide them together to check the joints.  If you’re alternating faces each joint will have an X up on one edge and down on the mating edge.

The joints should easily close with hand pressure.  If you have any gaps go back to the jointer for another pass.  Excessive glue and clamp pressure do not compensate for lousy joinery.

mark the faces Mark the faces. Once you’ve worked out the joints and orientation of the boards, make a face mark.  A big triangle will show you how the boards go together.  You shouldn’t be guessing at this while you’re working with glue and clamps.  The bigger the glue up, and the more pieces you’re working with, the more important a face mark becomes.

As I’m working with the boards I go for the best looking face, a function of grain and color.  You do not need to alternate growth rings, provided your material has been properly dried.

mask off clamps Prep your clamps.  If you’re using pipe clamps made up with black pipe, put masking tape on the pipe.  If you don’t, glue squeeze out can loosen up the black coating and allow it to migrate into your panel.  It can take A LOT of sanding or planing to remove those black marks.

apply glueApply glue.  Using a glue brush (see Sources) spread a uniform film of glue.  You only need to apply glue to one edge in each joint.

What about biscuits, dowels or some other joiner?  No need, as far as strength goes.  With good joinery the joint will be stronger than the surrounding wood.  Need proof?  Watch this video http://www.wwgoa.com/video/000330_strength-of-glue-joints/   On large glue ups you may want to add biscuits, or something similar, simply to help keep the faces aligned so you don’t have to work so hard to level the panel as you’re clamping it up.

proper glue coating How much glue?  Put on glue like you’d put on paint.  Go for a uniform coating that is opaque enough that you can barely see through it to the wood below.

clamping the panel Clamp the panel. Use an equal number of pipe clamps above and below the panel.  Having clamps above and below the panel, with equal pressure on all the clamps, helps keep the panel flat. The pipe clamps on top were made using galvanized pipe, instead of black, so masking tape isn’t required.

Don’t over tighten.  As soon as you see the joint close, you’re done with clamp pressure.  No need for clamp pads because the panel is oversized and the edges will get cut off later.

aligning panel faces Check alignment.  As you tighten the clamps you’ll need to manipulate the boards to make sure the faces are aligned.  Near the end of the panel you can bridge the seam with a small clamp.  As you tighten this clamp it will pull the faces into alignment.

slicing off excess glue Don’t wipe the squeeze out.  Wiping wet glue with a damp rag just pushes the glue around and makes an even bigger mess.  Allow the glue to dry until it’s rubbery, about 10-15 minutes, and slice it off with a chisel.  If you don’t wait long enough it’ll be too wet and make a big mess.  If you wait too long it’ll get too hard and you won’t be able to cut it off.  Check the squeeze out frequently to see if it’s hit the right consistency yet.  When it’s ready it’ll peel easily.

parallel jaw clamps Make glue ups easier.  If you want to simplify gluing up panels, consider upgrading to parallel jaw clamps.  There’s no need to put masking tape on the beam and, because the jaws are parallel to each other, there’s no need to clamp from below and above.  You’ll find parallel jaw clamps at woodworking specialty stores, from a variety of manufacturers.  A warning, these clamps aren’t inexpensive, but they make clamping panels (and doors) so much easier, they’re worth the price.

Why Alternate Faces on the Jointer?

When setting up the jointer your goal is to make the fence perfectly perpendicular to the table. That’s a great goal, but it doesn’t always happen. If the fence is off a little you’ll joint a slight angle onto the edges of your pieces.

angled edge In this picture the jointed boards are lying on a table with the face that was against the fence down on both boards.  You can see that because of the angled edge the joint won’t close unless I rock one of the boards up off the table.  That’s fine if you’re making a barrel, but no good for panels.

angled edge reversedThese are the same two boards, with one board flipped over.  Now the angled edges produced by the jointer complement each other, allowing the glue up to be flat.

If you know that your jointer fence is perfectly perpendicular you can ignore this aspect of the panel sequence.

Sources

Glue brushes #04Z51 Woodcraft www.woodcraft.com (800) 225-1153

Related stories

Jointing on a Router Table http://www.wwgoa.com/edge-joint-on-a-router-table/

How to Master the Jointer http://www.wwgoa.com/master-the-jointer/

Jointing with a Router  http://www.wwgoa.com/jointing-with-a-router/

Discussion
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28 Responses to “Gluing Up Panels”
  1. Ed Waite

    I also use Wax paper when gluing, it peels right off the glue and keeps it from dripping on my work bench.

    Reply
        • WWGOA Team

          Any type of wood can work, so the choice is based mainly on aesthetic preferences. In general here are a couple suggestions in choosing materials for a top:
          – Table tops can be subjected to a lot of abuse over the years, so unless you want a distressed look, it is best to go with a hard species such as maple, oak, walnut, or cherry. For a durable surface avoid softer woods such as pine or alder.- Large table tops, such as kitchen or dining tables, require large panel glue-ups. When choosing stock for a large glue up, it is important to find stock that is stable and relatively flat (free of sizable cups and twists) to begin with. If you have remove a lot of stock to establish flat, square stock, it might become too thin to maintain its structural integrity.
          Best of luck with your project. Paul

          Reply
          • Paul

            is it best to retain the tongue and groove or to plane it smooth before gluing?

          • Customer Service

            If I were gluing up panels with tongue and groove I would most likely cut both the tongue and the groove off in order to establish a seamless joint. That said, if the joint closed perfectly with only light hand pressure I would leave the tongue and groove intact. Normally, however there is a chamfered edge along a factory-made tongue and groove joint that would prevent a seamless glue up on a panel.
            Paul-WWGOA

  2. Chris Campbell

    After the 10 -15 minutes, do you remove the clamps to scrape the glue squeeze out off? Then do you re-clamp the piece for 3 – x number of hours in the case of white glue? Is the bond strong enough after 10 minutes for light manipulation?

    Reply
    • George Vondriska

      After 10 min I’ll cut the glue off where ever I can get to it, between the clamps. After 30 min or so I’d be comfortable taking the clamps off and gently handling the panel.

      Reply
  3. Ernie Richmann

    I have had good luck using a glue line blade and not using a jointer. Flipping boards is also a good idea after using the table saw. Plan ahead to get the desired pattern.

    Reply
  4. Brad

    When I joint boards for a panel glue-up, rather than tracking what face was toward or away from the fence, I simply mark one end of the board, and always run the boards through the jointer the same direction every time. This ensures the edges are jointed properly every time, regardless what edge was against the fence and when. Just another approach, might help some people not get confused…I’m easily confused. 😉

    Reply
  5. Biff Wellington

    Sorry to chime in so late. I do a lot of pine panels, the cheap flat sawn stuff from the Mega Lo Mart. I find that flipping alternate boards (grain direction) helps keep the panels from cupping.

    Reply
  6. Gary

    What if you don’t have access to a jointer? How would you proceed to get the edges ready for glue up?

    Reply
  7. Rich Lagrand

    Although not essential (as with black bars), I find that covering the bars of my clamps with wax paper goes a very long way to keeping glue off of the clamp, cutting way down on cleanup. Digging glue out of the bar grooves is definitely not fun and can wear them down if you get to aggressive about it.

    Reply
    • WWGOA Team

      There is no theoretical limit on the maximum length of a panel that can be glued. The practical limit comes into play with the capacity of your shop and equipment.

      Reply
  8. Michael

    George? I’m still a little confused on this. Can you do a detailed video on this? Going into what you mean by alternate faces on the jointer. It would be greatly appreciated! Thanks…

    Reply
  9. Jerry

    What about gluing end pieces across the panel? Do you have to be concerned with panel expansion and shrinkage? Is there a thread on this issue?

    Reply
  10. Alanna

    How would you go about clamping it all together if there aren’t any flat edges? I’m trying to repair a round kitchen table that has split down the middle.

    Reply
    • Customer Service

      Hi Alanna. I have emailed you a response on your question along with a photo.
      Thanks
      Jean-WWGOA Video Membership

      Reply