The table top is done, and now my attention turns to the base: Milling and glue-up of the walnut legs, and milling the quarter-sawn white oak for the aprons. In this post I illustrate how I go about gluing up the legs once the walnut is milled to rough dimensions.
Preparation for this glue-up is essential, as the following are mandatory for success:
- A glue that will not creep, and also provides a rigid, gap-filling glue line – I prefer to use Unibond 800, a two-part urea resin glue.
- Have a good clamping strategy – and plenty of clamps on-hand, as they will be needed in order to get a good glue line. I am glad I did not use the vacuum bag, as a lot of glue is squeezed out during the glue-up, as you will see.
- All materials should be stored in an area kept above 70°F, to ensure proper curing of the Unibond 800. In my case, this means the finishing room; I can keep it at temperature with a small ceramic heater.
- Although the two parts of this glue system can be measured by volume, the better method is do it by weight – therefore, a good, accurate balance is needed for this. I have a little electronic balance accurate to 0.1 grams, which is adequately accurate for this job – and it cost about $100 a couple of years ago.
- Proper mixing of the part-part system is required, until it is smooth and all clumps of the powder catalyst are dissolved/dispersed in the liquid resin.
- I like to use a rubber roller to spread the glue evenly on all surfaces. This is a brayer, which is typically used to apply printing ink or paint to a printing plate; it is available at craft supply stores.
- Take your time! One of the nice features about Unibond 800 is its long open time. So, relax, prepare a sufficient amount of glue for the job at hand, and proceed methodically.
Now, a few photos to illustrate some of the things I mentioned above.
Once everything is ready (clamps, milled boards, plastic sheets under everything, etc.), I proceed to weigh the Unibond 8700 components, and to mix thoroughly in a plastic beaker/measuring cup:
I pour an amount onto the surfaces, and proceed to spread the mixed glue evenly on the boards – notice I have applied blue painter’s tape to the bar on the clamps, to make removal of any glue squeeze-out easier:
Methodically I apply glue and spread it on all the surfaces I will be gluing up – remember, you have plenty of open time with this glue system:
Now I proceed to tighten the clamps, lightly at first on all of them, and then as tight as I can get things – and I use as many clamps as I can. Clamping blocks are a great help to do this:
After glue-up, I prefer to wait at least overnight, to let the glue cure properly. Then I do some clean-up using a scraper – this glue is tough, hard, and brittle:
Once I have one edge reasonably flat, I use the band saw to remove a little wood on the opposite side – and at the same time remove all the glue that squeezed out. This results in savings in time, and in muscle power:
Immediately after coming off the band saw I look at the glue line. The resulting glue line is small, thin, and even throughout, a great pay-off to the work:
Next: I finish milling the legs and aprons, and start work on the mortise & tenon joinery on the Leigh FMT.
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