The Dry Run: Assemble It Once With No Glue at All

Not an approximation — the actual clamps, in the actual positions, tightened as they will be. Then look at what happened. The usual discoveries: a clamp that will not reach, a bar that fouls another clamp, a jaw that lands on a face it will mark, and — most often — that you do not own enough clamps. Every one of those is a five-minute problem now and a ruined assembly later. Lay the clamps out open and ready afterwards, at the reach you measured. Hunting for a clamp with glue going off is exactly the situation the dry run exists to prevent.

With everything clamped dry, measure the diagonals, put a straightedge across the faces, and stand it on a flat surface to see whether it rocks. A frame that will not come square dry will not come square glued — the fault is in the parts, and this is the moment to find out which one. A carcass that rocks is twisted, and twist cured into a glue-up is permanent. Adjust until it is right with no glue involved. Then you know that when it goes wrong during the real glue-up, the cause is something you did in the last five minutes rather than something built into the parts.

While it is together dry, mark every joint — a pencil triangle across the whole assembly, or numbered pairs — so each part has one obvious home. Joints that were fitted to each other are not interchangeable. A tenon eased to fit its own mortise will be loose in the next one, and two dovetails that looked identical are not. Swapping them during the glue-up is a common and completely avoidable disaster. Mark on faces that will be inside the joint or planed off later. A cabinetmaker's triangle across the top of an assembled frame tells you orientation and order at a glance and disappears in the first cleanup.

Put the glue, the brush, the clamps, the cauls, a damp cloth and the square within reach before any glue is opened. Walk through the sequence once with your hands. The order matters more than it looks: which joint gets glue first, which sub-assembly goes together before the whole, which clamp goes on before another blocks it. Deciding that mid-glue-up is where mistakes come from. For anything with more joints than the open-time arithmetic allows — the adhesive rung computes this — plan it as STAGES from the start. Glue the two sides today, join them tomorrow. Nobody is fast enough to beat a skinned glue line, and planning to be is the underlying error.