The Amana church bench is a time-tested design.
Amana Church Bench – FineWoodworking
I don’t understand why the plank seat doesn’t split. front and rear legs are mortised into a sliding dovetail cleat which is pinned to the plank seat going the other way. Why doesn’t this cross grain restraint split the plank with seasonal movement? You’d think that the leg should only mortise into the cleat, rather than going all the way through both materials. That accounting for wood movement doesn’t seem to be required in this case.
What’s the difference between this cross grain restraint and one that might lead to cracking over time?
Replies
It would appear to me there is enough movement allowed on both sides of the mortised legs to prevent a split. Also, it should be considered in aligning the leg grain with the seat grain.
The seasonal change in the 6" between the legs in pine would be about 1/10 of an inch... well within "squish range" for a softwood. If it gets loose as a result the tapered mortises will just settle down and tighten with use. I wouldn't be surprised if the leg tenons poke out a bit on older benches.