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I decided to build a table out of 2x4s and such for Thanksgiving. I figured it would be a cool first woodworking project. The top went pretty well I think, but now it's time to attach the legs and I feel like there has to be a better solution than the one I'm thinking about using.

This 4x4 is being held in place by gravity!

So the 4x4 butts up directly to the 2x10, with the 2x4s at right angles. Everything is reasonably square, but the brackets that I'm planning on using have the tendency to induce a gap between the leg and the table top if there is any issue at all with the screw hole (tested this out on scrap), since the brackets are counter sunk.

One potential solution is using screws with heads that don't take advantage of the counter sink since errors can be corrected by sliding things around a bit, but that doesn't provide nearly the feeling of strength that using the counter sinks does.

Anyhow, I figured someone here might be able to offer some better ideas on how I can properly attach the legs to the top.

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  • Not sure of the metal in those braces but I have never had much luck with the cheaper ones holding under pressure. – Matt Nov 21 '15 at 5:59
  • Go into an Apple store, if one is near you. At the "Genius Bar" they have large wooden tables. Look under the table to see how the legs are joined. – Treow Wyrhta Nov 21 '15 at 10:50
  • @TreowWyrhta You mean the giant box joints? (Also if you feed them customers -- think Little Shop of Horrors but with a table -- apparently they grow larger). – Jason C Nov 21 '15 at 23:56
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Pocket hole joinery

One of the simplest ideas I could think of to address this would be to flip up the boards vertically and use pocket holes and screws into the legs.

Some good examples and picture come from a Community Project post about work benches: Community Project: Lets build a workbench!

Highlighting a picture from my unfinished work bench you can see where I had make the pocket holes. The same orientation of holes is what my table top and frame were made from. That bench is surprisingly very sturdy.

Pocket holes in workbench

Image from my backyard

All of this requires you have the hardware and/or jigs to make pocket holes. In my opinion they are totally worth it. I have used them on several of my projects and they are very sturdy.

Add a corner brace

Another idea that builds on my frame suggestion above, still relying on flipping the boards vertical, is to make or buy a corner brace. Note in the below picture that the brace is hiding pocket holes that join the boards to the leg.

Corner brace

Image from home-dzine.co.za

Many commercial corner braces, of various designs, are available as well. Like this metal brace.

Metal corner brace

Image from hertzfurniture.com

Mortise and Tenon

Another great, and simple, joinery technique to use would be mortise and tenons. However it looks like you have already made your cuts so making tenons would be out of the question. The would have to be long enough to go into the mortises of the 4x4.

Minimum: Flip up the boards

It will help mitigate racking forces against the legs.

I see in the picture that you have screwed the table top directly to your apron. I would expect as humidity/moisture levels changes that your table top, screws and apron will be moving. Depending on how much stress the expect you could expect some splitting and cracking in the boards. If I am wrong then forgive me but always remember the relationship between wood and water.

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  • +1 to flipping the 2x4s onto their edge and incorporating a corner brace. Depending on the look you're going for, you might consider putting a longish lag bolt through the 4x4 into each of the 2x4s. (In my opinion, this would be somewhat sturdier than pocket screws, especially since you don't appear to have lower stretchers as shown in @matt's first photo.) Regarding wood expansion and screws through the 2x4, you might google "figure 8 tabletop connector" for a solution that will enable wood expansion/contraction. – Aloysius Defenestrate Nov 21 '15 at 16:44
  • @AloysiusDefenestrate I can't picture the lag bolt idea.... Do you mean though the 4x4 into the 2x4 end grain? That would be a weaker connection would it not? Forgive if I misunderstood. Pocket screws would be going into face grain. yes..... depending on the designs stretchers would help but I don't think the op is using them. Doesnt need them either. – Matt Nov 21 '15 at 16:48
  • yes, into the end grain. I should have been specific that I was thinking of a lag that was about 10" long (through the 4x4, into the 2x4), so lots of bite into the 2x4. (Need to predrill an undersized hole in the 2x4.) My concern with the pocket screws is that they run parallel to the grain of the 2x4, so aren't super-super strong. The corner brace would go a really long way toward preventing the kind of force that would break the pocket screw connection, so maybe I'm overdoing it. – Aloysius Defenestrate Nov 21 '15 at 18:01
  • @AloysiusDefenestrate The screws though the face grain is not supposed to be an issue. The pocket screw heads are wider and would pull the 2x4 to the 4x4. The wide pocket screw head and screwing into face grain of the 4x4 is where the strength comes from. There are far stronger choices to go for here. That is just a simple one. – Matt Nov 21 '15 at 19:02
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    Hanger bolts might come in handy for the corner brace option, too, e.g. the detachable legs on my dining room table (they're very sturdy, and can be detached without pulling the bolts out of the legs). Lee Valley also sells some interesting looking insert hanger bolts. – Jason C Nov 22 '15 at 2:27
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All the information Matt provided on joinery is true and quality information. I had a neighbor who built a similar project a few years ago and we ended up with a alternate solution that may be helpful in this situation considering the point you are at. The metal brackets in your picture do not have any cross bracing and that is likely contributing to the instability. Perhaps use a bracket with some cross bracing like these pictures. Personally, for maximum stability, I would go with the wood bracket or something similar. I would apply wood glue and then a few screws. Don't go overboard with the screws on the wood brackets. Their main purpose will be to clamp the brackets while the glue cures. Their secondary purpose is as mechanical reinforcement. If you go with a metal bracket, the screws provide all the bond so be sure the shank of the screw is the same size as the hole so there is no play in it.

metal bracket 2 wood bracket

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