Build a Front for an Existing Cabinet
Page 3
Step 3: Glue the Doors
Now for some fun—it's door-clamping time. You've worked accurately so far, but it's no time to let your guard down. Clamp the doors square and flat in a clamping jig built from 3⁄4" plywood, with one square corner. Then glue the doors in two stages.
Glue the First Corner
Before clamping the first corner, check that all joints fit with the joiner plates in place. Make any adjustments before you slather the joints with glue! If the plates are loose in the slots, don't use yellow wood glue, which requires a tight fit. Instead, use polyurethane glue, which fills gaps and is incredibly strong (although it is harder to clean up and slower to set). Cover your glue joints with wax paper so the parts don't stick to the jig and the scrap-wood blocks that protect the parts from clamps.
Building Smarts
You can't have enough clamps! I've identified some of the most useful types in these photos. Buy clamps in pairs, but get an assortment. Different clamps have different virtues:
- C-clamps are strong, with a deep reach, but adjust slowly.
- Pipe clamps are long, easy to adjust, and strong. But they're clumsy, and have a shallow reach.
- Bar clamps have a longer reach, but usually are weaker than pipe clamps.
- Handscrews are strong, won't damage wood, and have a long reach. But they are slow to adjust and expensive.
- Quick-adjusting, one-hand bar clamps are, well, quick to adjust, but they are weaker than many other clamps.
It's tempting to glue the entire door at once, but that's foolhardy. It's much easier to get a rectangle if you glue one joint first.
Here's a trick for clamping parts with mitered ends: Dry-assemble the whole door, and then clamp the whole door to tighten the first joint.
Clamp the door in the clamping jig, holding the joint tight, square, and flat. The jig should be screwed to 2 × 4s to hold it flat. Glue only this one corner. Clean spilled carpenter's glue with a wet rag.
As you tighten the clamps, always check that:
The miters meet exactly at the corners.
The miter joints are closed.
The miter joints are compressed so the joints and the door are flat.
The door parts touch the rails on the gluing jig.
You've cleaned up extra glue.
Tighten the clamps gradually, making sure the door stays square.
When the glue is set (30 minutes for carpenter's glue, longer for polyurethane), remove the clamps.
Finish Gluing the Door
When the first joint is finished, glue the other three miter joints, add the joiner plates, and clamp. Insert a wood panel in the door before assembly. Insert glass when the door is finished, as described later. If you're using a 1⁄4" veneer plywood panel, squirt glue into the dado on each door part and insert the panel. If the plywood is loose in the dado, flip the door over and press nails into the back.
Push loose plywood toward the front of the dado with a 4-penny finish nail every 4" or so. Remove the nails after the glue dries.
Turn the door right side up and clamp as described earlier in the chapter.
Quickly assemble the door, before the glue sets. See the earlier discussion for important clamping considerations.