CRAMPING OF RISEN TABLE TOP VENEER

CRAMPING OF RISEN TABLE TOP VENEER
By Michael Barrington

We were asked to deal with very large 30ft dining table on five four-legged platform pedestals with a top of seven leaves 6ft wide, the centre leaf measured 6ft square, two were 5ft, two 4ft and two 3ft. The leaves were veneered in rosewood on 1 inch ply and the rosewood had patinated to an attractive pale colour. A wide crossbanded kingwood, ebony, box border surrounded the table top and a vertically banded frieze with gilt 2 dee moulding hind below the leaves. The table surface had suffered considerable light damage in that the so far unidentified finish had crazed along the grain over its entire surface area and there were something like 60 places where the veneer had risen in small areas of not more than 1inch in diameter.
The table appeared to have been made in the 1930s and bore the maker's brass name plates under the leaves and on the pedestals. We had between 4 and 5 weeks to complete the project.
I needed to know what adhesive had been used to put down the veneers so phoned the maker who said they did not hold records of their furniture over three years old but that if I was right about the date, and there was no way that I could be certain, the veneer would have been put down with hide glue. I went ahead on that basis which turned out to be right or at least compatible.
Putting down the bubbles was the first job and had to be done without altering the consistently pale colour of the rosewood. The first thing we did was a trial run on bubbles close enough to the edge to enable us to use standard bar cramps. MDF 22mm cauls of various sizes, faced with melamine were made. These will not stick to the surface and MDF and melamine are good heat sinks. Some of the bubbles went straight down after a cramping time of about three hours, while others were obstinate and took two ‘goes'. More obstinate ones had to have the bubbles split with a very sharp craft knife, hot glue was puddled on and a hot caul cramped to drive in the glue. We also encouraged the molten glue to penetrate by bouncing a plastic car window squeegee on the surface like a drain plunger. The squeegees can be bought in motor accessory shops in packets of four; they were popular at the time of England's disastrous efforts in the World football for supporting St George flags on vehicles. The whole operation of putting down the bubbled veneers lasted two weeks with cutting back and re-polishing being done in tandem as each leaf was finished.
Because of the hard use this table experiences, table-top polish and its solvent, applied conventionally with a rubber was used and this was compatible with the former/original layers. The owners were warned of this in advance but had no concerns and were enthusiastic that a hard and more ring resistant type of finish was to be used. The centre areas of the five inner leaves showed signs about 2ft wide of having carried heavy silver centre pieces and candelabra, in that they bore a multitude of score marks and indentations. But such is the quality of the plywood substrate, this damage, except for one small area was veneer deep only and was easily concealed during polishing.
The majority of the bubbled areas were outside the reach of even the deepest throated cramps, so we had to make special bridges. In any case whatever cramping method we used had to cater for multiple areas of simultaneous cramping because time was not on our side. I bought a mixture of a dozen single and double cramp heads and made up two steel bridges of 6ft and 8ft. These could be cramped to the edges of the leaves at almost any angle to carry cramp heads. The cramps themselves were almost certainly of Far Eastern origin, strong but badly made in that their slots were not machined but cast with rounded throats, which prevented the cramps from standing vertically under the bridge bars. All the cramp slots had to be machined accurately in a milling machine which took some hours but was successful.

The steel bridge bars were of 40mm x 10mm black mild steel with double angle-iron "T" stands bolted to each end. One stand on each bar could be repositioned wherever it was needed. The stands were riveted together and the undersides were faced with cork and goat skin to protect the table. They were cramped to the table edges with a pair of G cramps with the bars at angles convenient to position cramps over the damaged areas. We used up to four cramps on a bridge bar at a time.

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