Glueing Up a Mitered Bar Top

Adhesive choice and clamping and fastening methods for a tricky glue-up problem. June 30, 2007

Question
I have a client wanting a small bar built out of cherry for his soon to be finished basement. We will be mimicking a commercial version he saw in a local restaurant. I inspected the bar carefully and feel fully confident in the task at hand even though I have never taken a bar on before. However, there was one problem I immediately detected and I know I can not afford to make the same mistake. They used draw bolts or "dog bones" to assemble the miters and I can't imagine that they didn't use glue. For the most part the miters held together pretty good, but there were a few places where they had opened up, obviously in between the fasteners. Does anyone have experience with a foolproof method so this will not occur? I was considering a series of pockets to drive large cabinet screws, so I wouldn't have to mess with the draw bolts.

Forum Responses
(Furniture Making Forum)
From contributor V:
I have used the draw bolts and pocket screws. I think you will find that on thicker material like bar tops, the pocket screws can misalign the surfaces. Though they can be sanded in, it puts unequal stress on the bottom of the wood and does nothing for the top of the joint except maybe pull it apart with the downward pressure.



From contributor A:
I just finished a mitered 24" wide quatersawn oak countertop for a kitchen island. I used biscuits for alignment and shear strength and draw bolts about every 6 inches. Glued the whole thing with epoxy resin. The trick with epoxy is to use thin stuff, let it soak in for 10 minutes, and then throw some thickener in it for the final glue. The combination of biscuits and soaked-in epoxy kind of changes that joint from a butted yellow glue. I also glued and stapled a 6" piece of plywood to the underside.


From contributor V:
I use epoxy on a very regular basis and one thing to keep in mind is that unlike wood glue, epoxy works on volume of glue. If you don't have enough, it won't bond well and it doesn't soak in that much.


From contributor J:
I made a quarter sawn Sapele kitchen countertop for client a few years ago. I used a double spline and epoxy. It has held up well. Since you are gluing the miter, make sure your ends have a lot of room to move or the mitre will fail. If you do use epoxy, contributor A is correct in his application advice. Always coat all surfaces with unthickened epoxy first and then add whatever additives you need. This is even more critical when dealing with a miter because you are dealing with half end grain that can suck enough epoxy out of the joint to make it weak. Also, don't crush it with the clamps. Epoxy does not need a lot of clamping pressure.


The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor S:
We just produced a cherry bar top with a long miter. The technique was a series of floating tenons (dominoes) within the miter and glued up with Gorilla Glue (very strong adhesive). The clamping technique was created by gluing on a series of triangle blocks along the edges which create parallel surfaces to the glue joint as well as an edge to be used for clamping, in order to close up the miter while gluing.

Between the triangle glue blocks and top edge is brown paper so that these blocks can be broken off after clamping is completed. Titebond is used (a rub joint will do) and needs to set up overnight prior to clamping. It's a great technique that gives full clamping ability on any miter joint. Once done, break off the triangles with a hammer, scrape and sand the brown paper off and voila.