Best Practice For Cabinet Glue Up? *UPDATED - Now Complete*

[carolina_woodworker]

I am in the process of completely renovating my workshop. Thankfully all the electrical, insulating, sheetrock, and painting are done and I am firing up the fun tools again. I am currently building some storage cabinets to hang on a french cleat system. You can see my SketchUp design above. Considering my less than stellar performance on past projects, I am very pleased with the accuracy I was able achieve with my cuts and things fit together quite well when dry-fitting:

I was planning to first glue up all pieces except for the back so that I can later clamp the pieces comprising the hardwood oak frame to the front using clamps which stretch through where the back will ultimately go. My problem is that when I do a dry fit I have to push the bottom piece of the cabinet up slightly so that the dado in the back can receive it:

I am worried that if I do not glue the back in as well during the initial glue up that I will have problems getting it to fit afterwards. Besides that, I am not sure that I have enough clamps or even could get as good of a clamping job when trying to clamp up all pieces at once. I am a very amateur woodworker so I don't know if there are best practices or good guidelines to follow here. Is my original glue up plan sound? The only other alternatives I have thought up are:

A ) Glue up everything except for the back. However, place it in dry while gluing and clamping all other pieces. The plan would be to remove it as soon as everything was fitted and clamped. Concerns here are that the back will not be able to be removed due to squeeze out or due to the clamping pressure. Seems unlikely that I could remove it while having sufficient clamping pressure on the rest of the piece and I fear that clamping down harder post-removal could introduce movement.

B ) Glue up everything including the back and then use cauls when gluing the hardwood frame to the cabinet. I am unconvinced that I will get adequate clamping pressure on the frame with this approach.

Any guidance here would be greatly appreciated. I do not want to mess this up as it has taken quite some time to get to this point. Failure is not an option!

[PaulMarcel]

If you are worried about the back, then use some squaring cauls. Very easy to make out of MDF. They look like this:

Just make sure the 90º corner is 90º; the 45º can be whatever as it isn't involved. Drill out 2 big holes with hole-cutting drill bits and use a handsaw to lop off the 90º corner (here I showed it round, but just lop off a bit of it). As you march across your shelves gluing them in place, place a squaring caul on the two pieces. Put a clamp head in each hole clamping to its adjacent side. The reason the corner is lopped off is to keep it away from squeezeout and to make sure that any error at the joint doesn't cause the square to clamp out of square. You could crank out a bunch of these with scrap MDF or ply. Also, you don't crank down on the clamps; get them snug so they don't move, but hold the pieces in place. You'll still need to clamp the shelves down into their dados.

Thing is, you could do one shelf at a time if you are limited on clamps: use the squaring cauls and clamps to push down into the dados. After an hour or so, they should be strong enough to let you remove the clamps and move on to the next shelves. Once all the shelves are in, pop on the back and get clamps on the whole thing and leave overnight. I'd use the squaring cauls on that, too, to make sure everything stays square while you assemble.

It's a nice looking cabinet. For my first ply cabinet, I believed the catalog that said "plywood straight bits" were really sized for plywood. Man, that was dumb.

[Rutabagared]

I would dry fit the back during the glue-up of the cabinet. Use a few screws to attach it to reduce the number of clamps required. Add some pieces of waxed paper between the back and the cabinet anywhere you have concerns about squeeze out. It's thin enough not to cause problems.

After the cabinet is thoroughly dry, remove the back. Adding the back later will also make it much easier to apply a finish to the inside. Nice cabinet by the way. Good luck!

Joe

[carolina_woodworker]

The cabinet is complete and I thought I'd give an update on what I did and how well it worked. I ended up using painter's tape to tape wax paper to the inside of the back. I then glued up the carcass with the back dry fit. Turned out that squeeze out was no problem whatsoever so the wax paper was not needed. I then squared up the face using a block plane (some of the shelves were slightly long). Then I cut and glued the face frame and then finally the back. The finish is a couple of coats of tung oil followed by 2-3 coats of poly. Thanks for the ideas. It ultimately turned out better than I had hoped. It is super strong and hung on a single french cleat. I was going to try and use two cleats however the wall is warped and I couldn't see how to get the second cleat to fit correctly. Luckily it feels completely secure with the one cleat.