Tuesday, February 16, 2010

Table Making- Top Glueup

The layout has been examined by my clients, so it's time to move ahead with the glueup.

I start with one of the table halves. I place the entire half in the clamps, but only glue one joint.

I glue only one joint at a time. This makes it easy to maintain perfect alignment. Any slippage means table thickness lost. I put the entire half in the clamps at once, it's easier to keep track of parts this way, and avoids fibre crushing from the clamps at every joint.

I then glue and clamp the second half.

Then the same with the first leaf.

By now the first joint has firmed up enough to maintain it's bond, so I unclamp it, glue the second joint, and then re-clamp it.

Now I add the second leaf into the routine.

I repeat the process until the entire table is glued up.

My goal is achieved, a dead-flat glue up.

I'm lucky to have access to a clamp rack. If I was using pipe or bar clamps I would alternate their postions, one on top, the next one below, to control cupping.

I give my hands a break, I've opened and closed the clamps almost 100 times, then I fill small flaws. Doing this while the table is in clamps gives the fill time to dry, and it is leveled while I flatten the table.

I start by using an awl to remove punky wood or pith, being careful to maintain the natural edge of the void. I also circle the hole to make it easy to find while I fill.

Conventional wood filler is a shoddy product that has no place in my shop. Instead I colour two part epoxy with universal tints, black for Cherry to imitate pitch pockets, brown for everything else. A little tint goes a long way, and too much inhibits the epoxys cure, so I gradually add it untill I get the shade I'm looking for. I keep mixing to a minimum to avoid air bubbles, and I flow the epoxy into the hole to avoid air pockets.

Dried glue is hard on sanding belts, so squeeze out must be removed. I've had glue pull up chips after it's dried, so I scrape off the top while it's still soft.

If there's a rush for the clamp rack I'll pull the parts out after an hour, but I like to leave them in for as long as I can. I won't work the surface for at least 24 hours. The joints have absorbed moisture from the glue, and have swollen a minute amount. If I worked it now, the top would be flat, but the moisture would leave the joints and they would shrink. These collapsed glue joints would show up as lines after finishing and be unsightly.

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I'm a woodworker on the Canadian prairie.