learner6
Grumbler in Training
I am currently using a semi-pro hand underpinner & clamp & have suffered from mitre corners opening up after a few weeks. Corners have been pinned & glued with PVA but I think the problem is the short depth of wedges I have been using, combined with wood moulding that can be quite warped & stresses the joints. I am now using a deeper wedge (12 mm) which gives a good 75% penetration of moulding depth. What is a good rule of thumb for selecting wedge sizes that give good joint strength but does not risk break-out on the moulding face?