Sunday, 4 August 2013

A Tale of Two Tables: 6. Spit and Polish

Here begins the final post in the table saga. It has been a long time coming - the project has taken 18 months from conception to completion but it is done. The observant amongst you will notice that these photos are all of the large table - the small table was finished in the gloom of the evenings. Enough waffle, onto the details! 

We liberally applied a belt sander to take out the slight ridges left after biscuit jointing the top. In a heatwave this was warm work. My hands were turned black with a combination of oak dust and sweat! To get a super smooth finish on the top we then ran over it all with a random orbital sander and 180 then 240 grit paper. 

One smooth, dusty table top.
To get the finish we wanted required several finished, all of which could have been used in their own right. The frame was also a slightly different finish from the top - just to keep things complicated (actually for different wear characteristics but I shall come to that). For the top and frame we applied two coats of Danish oil to bring out the grain somewhat and accelerate the ageing. It should continue to age and mellow further but we are impatient and didn't want to wait 30 years.

Coat two of Danish oil goes on.
The Danish oil will protect the wood to a certain extent but we wanted a very durable surface for the top, one that will stand up to the abuses of many years. There will be many who will gasp when I say what we did next but it should allow us to use and love the table rather than handle it with kid gloves. We basted the top in waterproof gloss varnish. Heinous crime as that is, it provides the waterproof barrier to allow us to not worry when someone spills a glass of wine over it. But it isn't a nice finish. In order to take a final finish of beeswax (which we also applied to the frame) we used wire wool to take the top down to a matt finish. This should allow us to know when we need to add more beeswax as the table will become matt. There is something rather odd about sanding down a layer of finish!

Wire wool applied with the mounds of dust to clean.
The beeswax layer came next to bring it up to its full shine. This was a most rewarding layer to add!

Jenny applies the finishing touches to the polish.

One finished top.
For those of you who didn't see it earlier - this is what the finish does to spilt water. Nicely repellent.

Water pooling on the table top.
With the top and frame finished the final job of joining the two remained. This is an important stage to plan - as I mentioned in the first table post the wood will keep moving, for many years to come. If the top is simply screwed to the frame it will probably warp and crack. It needs to be able to expand and contract, notably across the grain (the width of our table). There are many methods of attaching a top to allow this, primarily falling either into a category of a widened screw hole or a lip / grove combination on the fitting. 

I decided to take a simplified approach to the traditional tongued block and groove on the frame by using a half glued biscuit joint. I glued the biscuit into blocks and put matching groves in the frame. In the middle of the width a block is screwed to the frame and attached to the top with a single screw to provide a center for expansion / contraction. 

Everything was piloted and countersunk at this point as driving screws into oak is not an easy thing to do. This is exacerbated by the fact I have used brass screws to prevent it reacting with the oak over time. These are not as strong as steel screws and are also slot heads rather than plus or posi, giving a poorer grip and greater liability to get graunched. Steel and oak react over time, producing a black iron oxide. This then gets worse with atmospheric sulphur by producing sulphuric acid! Not great in a table that I would like to outlive me. Hence brass screws.

Cutting the blocks.

Block sat beside its groove awaiting fitting.

Blocks being fitted. Note the smaller screw block in the center.
 And finally, a finished table!

Finished table.

Christening the table.

Previously: 5. It's got legs

Or read the whole series from the beginning: 1. Grand Designs


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