Simple connectors

One of the simpler methods of connecting cope and drag together is with a metal corner piece with a bolt to line the flaskhalves up and to clamp them together. It works good but a disadvantage is that there is no guidance at the last moment when you recouple the cope and drag (after removing the pattern).

Advanced flask connectors

The picture speaks for itself. The long guidance pins give less problems when putting the halves together. To prevent the cope and drag form floating during the pour, they are clamped together with these little snapping devices.

The smaller flasks are made of 18 mm plywood. Because the plywood can't take large forces the bigger flasks are made of massive wood.