I recently had an experience which I think is worthy of mention.
I had built a substantial front door for our house in Kelowna about twelve years ago. The stock is 1-3/4 inches thick, and the material is alder. The design is 100% dowel construction.
The door faces due south, and for several hours per day, during the summer the door surface is subject to intense heat. We are in an inland area with a continental climate so the temperatures can range from minus 15 F in the winter to highs in the high 90’s in August. In other words extreme variations.
In early 2017 I noticed the surface coating was deteriorating, so decided to remove and recondition the external surface. I was at that time curious about the condition of the joints both at the juncture of the rails and stiles, but also at the three wide carved panels, which were also doweled.
After extensive sanding down to 220 grit and examination of the surfaces and joints I found everything was in first class condition with no signs of separation or weakness whatsoever.
People underestimate the strength of dowel systems. The strength of our system is related to (1) Accuracy. (2) Geometric configuration (contoured shape) (3) Close spacing. Other factors are the emergence of high quality hardwood dowels, and superlative glues.
About eight years ago we designed and built a rock solid work bench from Douglas Fir. It’s on castors, is used and moved daily and remains rock solid to this day.
Some of the items of furniture I’ve designed were built twenty to twenty five years ago these include desks, dining tables, chairs, and numerous other items. These remain in use today.