Assembly of Cherry Dresser 60" x 30" tall
I have often thought it is too bad that our case joinery is hidden inside unseen. So often today even high end cases are put together in a simple manner, relying on pocket screws or biscuits, or in the case of kitchen cabinets, glue and nails.
Steve needed a hand with the long clamps and many pieces so I took the opportunity to snap a few pictures. Warning- this blog post is long! I have problems limiting myself when talking about building furniture.
Steve needed a hand with the long clamps and many pieces so I took the opportunity to snap a few pictures. Warning- this blog post is long! I have problems limiting myself when talking about building furniture.
 | We don't preglue components, let them cure then assemble the assemblies. Everything assembles in one go. Once in place, each part presses against the previously inserted part creating an interlocking case. Many of the members are impossible to clamp into place until the entire unit is assembled. into one piece. |
The next photo shows a side panel freshly assembled and ready to go onto the main case.
Face gluing alone is not adequate for our standards even though we use boat building epoxy as an adhesive. The strength of Aliphatic Resin (woodworking or "Elmers" glue) glue is inadequate due to its brittleness and inability to adjust to varying fits. We only use Apiphatic resin glue on bent and edge laminations.
Granted, epoxy will not disassemble, but who is disassembling our furniture? And why would it need to be dissassembling? These joints hold well past the strength of the wood. In other words run over the case with a forklift and broken wood members are left but the areas containing joints remain intact. Don't ask how we know that.
The Domino tenons where the leg meet the side panel are difficult to see so look closely. Face gluing alone is not adequate for our standards. The inner end panels are .75" hardwood plywood (which may legally be called "Solid Wood" but being a different animal we call it what it is). If solid wood panels are to be used on the end the panels must be allowed to "float" .19" to allow for seasonal wood movement (yes every season -every year) . Our rule of thumb is to allow for .125" shrinkage/swelling per 1 foot of width. Wood does not measurably shrink or swell in length (along the grain), hence the often overlooked wood construction rules.
Note the mortises (slots) which will accept domino tenons when the subsequent parts are assembled.
Another advantage of Epoxy is the color. Unlike Aliphatic resin glue which leaves harsh spots if any excess glue remains in the wood grain, epoxy has a similar color to clear wood finish, therefore cleanup is not as crucial. Yellow glue cleanup need be so thorough people will use too little adhesive for the job just so there are no glue spots when dry. FYI we do wipe the excess epoxy adhesive off and rub dry. Five minutes of easy cleanup can save 45 minutes of hard cleaning and trimming!
 Note the adhesive squeeze-out at right! If no squeeze-out how do we know there is enough adhesive in the joint? "Don't forget the cleanup Steve." Then Steve says "I thought that was your job Greg". No one likes the cleanup part but we've all had to chip off cured epoxy the next day. |  |
The vertical arrows direct you to where the bottom is inserted (the case keeps alternating between upside down and vice versa throughout assembly). The bottom presses against the back, tightening the previously assembled component into place.
The arrow shows the vector of force tightening the back into place.
The mortices are visible in the parts getting assembled. No screws or nails here. All mating faces and tenons are glued.
Note the mortices waiting to get glue before the tenons.
The vertical stiles are the point where assembly gets difficult. We have to get the rest of the front loose enough to spread the members apart so the domino tenons on all three sides can slip into their mortises.
At this point the case is at risk of falling apart as we work because of working at slipping all the tenons into place.
Large case assembly requires everyones wits and focus, so it is not a task to start right before lunch or at the end of the day.
Somewhere near the end we flipped the case upright Note the assembly blocks under the rails (magenta arrow). They provide total control over the flatness of the case. Squareness is also of utmost importance. If all the parts were made flat, square and accurate the case will naturally assemble pretty much the same, but it requires small tweaks to get it to a perfect final position. Changing the position and/or pressure of a clamp will tweak the case into the desired position. The completed case will end up exactly the same as when it was glued up, so we check it for several hours after assembly to make sure it wasn't bumped. The epoxy cures in twelve hours, and we keep the left over adhesive in the cup next to the case to confirm the cure.
I've never weighed one of these assemblies with all the clamps on. By the time we're done it has twelve iron pipe clamps on. Planning on having a clamping spot available becomes quite a challenge with that many clamps.
Because of the possibility of prematurely unclamping before the adhesive has cured, no one will unclamp someone elses case. I have seen things come up people move onto other projects, leaving a fresh case in the clamps for days at a time while drawers are baeing made.
The next stage is making the dovetailed drawers. That is another blog post but here is a picture of the drawer side stock getting glued. We bring in large units of local Broadleaf Maple from Northwest Hardwoods in Arlington and glue it up into the largest panels to fit in our clamps, then rip off the drawer sides as needed. We get amazing yield using that method, and it is much more sensible than looking for boards to glue up into each individual drawers sides and keep track of each drawer. This Maple is considered "Mill Run" (a lower grade) so we do have to defect out knots and such. Patches of figuring abound in each drawer, just not to the extent of Maple selected for heavy figuring.
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