Getting close to finishing my 48" x 90" assembly table.
This is a long post with lots of pics. Since I'm fairly new to woodworking on this level, I thought it might be helpful to others. Nearly all of these ideas and construction techniques I learned through researching posts here and elsewhere (thank you!), so I've pulled together a few in one place.
Features of the assembly table include:
• A mortise and tenon base (domino xl)
• Kreg Clamp Trak on two sides with 90 degree corner
• Torsion box top with formica microdot laminate surface (glue pops off)
• Quick release front vise with the back jaw buried under the maple skirt and an 18" walnut jaw insert.
• Locking casters
• 48" x 90" and 36" high. The height is prefect for the work I'll be doing (constructing mortise and tenon cedar gates) but of course would be too high for cabinet construction.
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Still need to put in a few dog/holdfast holes in the top (maybe), add a few holes in the front legs for holdfasts, and eventually add drawers underneath on the side with the vise. My thinking is that the face frame for the drawers on the vise side will flush the legs on the front with skirt on the table top. I'm not sure this is necessary so I'm going to use the table awhile before deciding exactly how to proceed. Another option would be to add a deadman but that seems a bit much for an assembly table. The other three sides of the table top overhang the base 5" or more for clamping.
The back of the vise is buried under the maple skirt. Instead of routing out the table for the back vise jaw, I added 1/2" plywood (leftover scraps from the torsion box) to the table edge on both sides of the jaw. I still needed to rout out about 1/8" from the back of the maple skirt board but that was much easier. I cut the width of the 1/2" plywood a bit short which leaves a groove between the skirt and the table base. This could be used for a deadman later on ... but I'm not sure I'll go to that trouble. It's an assembly table, not a bench. Right?
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Construction
I built the base first.
I used wood I had on hand so the base is tight-grain lodgepole pine assembled with the domino xl. First project using the domino, and wow, what a machine. While it still took a fair bit of time, the assembly itself was fairly easy and the joints spot on.
The legs are a beefy 2.5" x 3.5". The three leg assemblies were glued up first and then the three sections joined together.
Some very good advice I read beforehand on domino joinery was to fully seat the tenon in one mortise before pulling the joint together. I forgot to do this on one stretcher assembly and, sure enough, the hydraulic lock made it very difficult to close the joint.
Having three sections made it difficult to keep everything in one plane but not impossible. In the end, the base was about 1/32" out of square which was perfect acceptable for this project.
I then leveled the base and used 2x4s (jointed) on top of the base for a flat reference surface on which to construct the torsion box (a la wood whisperer).
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Table top is a torsion box.
I used 1/2" fir plywood with 1" x 3" pine grid and 2" x 4" (ripped down to 3") for the outside. (I really, really hate working with MDF). Moisture content was 8 percent for solid wood parts. For the long side with the kreg track I doubled up the 2x stock (glued them up first, then milled) to provide solid wood for the hold down bolts. Kreg clamps can exert 400 lbs. of force. I also preinstalled built up blocking (1x pine glued up) for the front vise and another double 2x stock cross piece running the width of the table in front of the vise for dog/holdfast holes (see below). With the solid wood I can drill all the way through the table, and holdfasts should work as well.
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The torsion box is heavy but not too heavy for one person to flip (carefully). Helps to have a sturdy base. It turned out flat enough (very slight fall off on the ends) for my purposes. I actually remembered to temporarily preinstall the vise when the torsion box was still upside down (from attaching the bottom sheet of plywood). Much easier way to install the vise. You can see the two front bolts for the vise on the underside. Then, once the torsion box is flipped with its face up, it's easy to slide the vise onto the bolts, tighten, and add the remaining two lag bolts.
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The Kreg Trak installation took more time than I thought. 1/4" bolts run through the top and are held with a washer and nut on the bottom. I buried the nut on the bottom in a 1x4 with countersunk holes attached to the underside of the table to allow clamping without interference.
Kreg recommends spacing of bolts to be no more than 4" OC. On their own tables they use 2" OC. I split the difference with 3", which meant a total of 72 holes drilled straight down through 4". Since the outside set of bolts is only 3/8" from the edge of the table, the holes need to be pretty close to plumb. I used the CD trick with a handheld drill and got close enough ... 72 times!
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Then a sheet of 3/4" plywood is added (with section for trak cut out) which puts the Kreg Trak slightly below the table top. Below: 3/4" plywood on and prepped for laminate installation. Blue tape is to keep contact cement off the edges of the plywood and the bolts for the track.
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I used trim head screws to attach the skirting (maple and cherry ... what I had on hand). I filled the countersunk round holes (predrilled oversized) with square walnut pegs. (Who says you can't put a square peg in a round hole!). The hole is the width of the peg so when you drive the peg in (with a dab of glue), the corners of the peg cut into the wood and remains square (or diamond). I don't have a true flush cut saw but the japanese combination saw I picked up at the big box store worked great. Sand flush and done. The square peg method isn't perfect but I much prefer it to round plugs. The imperfections are what I like. That, and it's pretty darn fast and easy too.
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I finished the wood with a commercial oil/wax floor finish that is wiped on.
A few thoughts (right or wrong, still learning):
- I designed the base as an open frame so I can put drawers in the front and use the back as an acclimation rack for pre milled gate pieces. Or not. My thought was that this construction provides options to mix and match features as I progress and figure out what I really need (and I really do need drawer space). It also just seems beefier to me than plywood boxes.
- The Kreg Trak has already been very useful. Even if I don't use it for pocket screwed face frames (and I might someday) it provides great hold down capacity for just about everything, including I suspect domino joinery. With the added little stops from Kreg, having a perfect 90 degree reference corner also seem like it could come in handy.
- The laminate top is great. Really great, and not just because it looks cool. Glue does pop off. And the microdot finish, slightly dimpled like a golf ball, is what is used on some commercial router tables, etc. (or so I understand). Yes, it will get dinged and likely ugly over time but for an extra $100, it seems like a good investment. And I can always throw another layer on top and do what I should have done in the first place - run it over the top of the skirt boards and put a nice chamfer on the edge.
- The front vise is also handy. Do you really need one on an assembly table? Maybe not, especially if you've already built your work bench, which I haven't. This definitely isn't a substitute for a real workbench but the features will get me by for awhile with what I'm currently doing (including a couple of swipes with a jointer plane on a board edge). And I suspect it will come in handy for domino joinery as well and other things I can't foresee.
- Do you need a flush front face on the assembly table? Probably not, especially since you can't clamp to the table top on that side. But again, stopgap measure before I build a real workbench.
Thanks for looking!
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Originally Posted by Michael Handrinos
