Over on another thread, we were having some friendly discussion on whether dowel joints were strong enough for use on chairs and other furniture whose joints must endure a lot of stress.
Specifically, Mike Henderson made reference to having seen dowel joints fail in chair joints. I questioned the age of the joint, type of glue, etc.
Well today, I was at my Mom's having tea with family, and my brother noticed one of the joints was coming apart on Mom's antique coffee table. I thought to myself: "Self, I wonder if that is a dowel joint..." So, as soon as we got the hot tea off the table, I gently pulled it apart. Sure enough, it was/is a dowel joint. (Mom was yelling: "Don't DO that, you're going to BREAK it!!!")
I don't know how old the coffee table is; just that it is at least 40 years old. Probably more like 80. It appears as if the builder didn't apply glue to the joint itself, but just the two dowels. It is end grain to face grain, so I guess that's not a HUGE crime... I can't tell for sure whether the glue is hide or yellow glue. Half the joint (the opposite side from shown in the attached photos) seems to be either molded or broken away. Probably from multiple moves and dragging it across floors.
Also, only two dowels were used, and there is easily room for 3 or 4 dowels in that area.
My judgement says that this wouldn't have lasted even if it were a M&T. I think the joint failed due to the age of the glue and/or rotten wood at the back of the joint.
The whole point of starting this thread is to provide us Creekers with data. We can all draw our own conclusions based on what is shown here. I'm particularly interested in failures of dowel joints for now, but we can use it for all kinds of joinery.