2

What is the best way to join these wooden beams together, to form a rectangle box which is capable of significant weight? I'd like the ability to deconstruct it, so something involving metal bolts would be preferred.

Here is an example of what the end result would look like, however they are using screws, which I'd like to avoid.

enter image description here

I'm not sure if I should be using a steel side plate on each corner, or if I should put a bolt straight through and join each beam together. Although if I use bolts, then I always end up with one half being loose (as they overlap).

SleepyCal
  • 123
  • 4
  • 2
    how is the load going to applied? straight vertical compression, or with twisting or lateral loading as well? how heavy a load are your trying to support? what material? softwood or hardwood? –  May 24 '16 at 13:49
  • Do you mean bolts as in nuts and bolts, or lag bolts? – The Evil Greebo May 24 '16 at 13:59
  • @personalprivacyadvocate Majority will be vertical compression, but for device which are only mounted on the front panel, there will be a certain amount of twisting as well – SleepyCal May 24 '16 at 15:46
  • @TheEvilGreebo Nuts and bolts – SleepyCal May 24 '16 at 15:46
  • Someone else can expand on this as an answer if they want, but google "cross dowel bolt". It'll pretty much explain itself. And if you won the lottery recently, google "Veritas Special Bench Bolts" – Aloysius Defenestrate May 25 '16 at 00:51
  • @AloysiusDefenestrate Perfect, that's exactly what I was looking for! Apparently dowels offer the most strength when compared against other joint types, such as a box joint, is this true? – SleepyCal May 25 '16 at 08:46
  • True that it makes an extremely strong joint -- more than enough for your application. Comparing it to other joints depends very much on how the other joints are made. – Aloysius Defenestrate May 25 '16 at 14:44
  • You say you'd like to be able to disassemble the rack, but want to avoid screws. A bold is simply a large screw with a different type of head, so I'm not sure of your concern about using the pocket-screw joints shown in your image. If you don't have the jig to make the pockets, basic ones can be had inexpensively (for example only). – FreeMan May 26 '16 at 13:24

1 Answers1

4

I can't say this is the best way to bolt together a 90° angle but this way of using bolts and captive nuts is widely used in workbench construction where it has to withstand considerable racking forces so it's definitely one good way:

Bolted leg and rail

Source: Master Cabinetmaker's Bench on Popular Woodworking.

Instead of having the shallow mortise and the tenon to prevent twisting you can use a pair of bolts, with the end of the rails flush against the uprights:

Twinned bolts

Source: How To Make A Workbench on I Built It.

As you can see the washer and bolt head can also remain on the surface if they won't get in the way.

Another option is just having one bolt (usually in the centre but sometimes offset lower) along with one or more dowels as shown in one of the images in this previous Answer.

Community
  • 1
Graphus
  • 65,691
  • 3
  • 50
  • 139