Andyp wrote:I have done some dummy runs on some offcuts and the dowels are a very tight fit. I really do not think that they would come apart if I knocked them fully home.
That's happened to me so I usually do a dummy run with looser or old dowels to make sure everything goes together
and can be knocked apart again
AndyT wrote:Dowels need at least one longitudinal groove, to let glue get past them as they are knocked home.
If there's no escape route for the glue, a dowel can work like a hydraulic ram and make it burst through the surface of the wood. Or just stop you getting the joint together.
On a plain dowel the groove is usually done with by putting a tenon saw in the vice and running the dowel along the the teeth, but yep, you must provide an exit for unwanted glue or you're liable to get 'hydraulic lock'. Bad news - Rob
I no longer work for Axminster Tools & Machinery.