Dining Chairs Pt 1 archive

Friday 15 August 2008

Robert Ingham designs and constructs a set of fine dining chairs

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I was asked by a customer to make a set of dining chairs to replace a collection of very old Windsor chairs that were showing advanced signs of deterioration. They were having to be repaired frequently because of the very dry atmosphere of the room, due in part to the under floor heating on which they stood. As is often the case with a commission, a visit to the location was necessary and this gave me the opportunity to discuss particular requirements and to establish a brief from which to develop the design.

Although there were other items of modern design in the house, the 'family' room contained a mix of older pieces. A Welsh dresser graced one wall and an old Dutch refectory table formed the centrepiece with the Windsor chairs around it. The wood of all the pieces had aged and was quite dark in colour. This had a strong influence on the choice of timber for the new chairs, so we decided on fumed oak.

The under heated floor was covered with tiles that had quite a rough uneven surface. This prompted the use of three legs instead of four, which would have been unstable.

Understated

The hardness of the contoured wooden seats of the Windsor chairs had served their purpose well over the years so the decision to avoid upholstery fed into the design. Laminated curves could fulfil the function so this approach was included in the brief. After much discussion about the function of the chairs, the final requirement was stated and this was quite difficult to interpret. The chairs should not have any wow factor.

As a designer, I had never been asked to understate a design before. In the appraisal of any piece of expressive work, it is up the viewer to determine whether an object conveys the complex intentions of the designer. I found it very difficult to come to terms with this aspect of the brief so I suggested that the choice of the colour of fumed oak might go some way towards reducing the visual impact of the design.

Design

I worked on the design in sketch form and then sent the customer a computer generated perspective line drawing. He felt that while the drawing conveyed quite a lot about the appearance of the chairs, it did not say sufficient about the posture and comfort. To resolve this problem, I made a mock-up from MDF. The seat and back were laminated using bendy ply to speed up the process. Fortunately, I had made the moulds for a previous chair, so I decided to use them again for the mock-up. It was a typical example of the expectation that one feels when a lot of work goes into making a jig which only gets used once.

Once the framework was complete, I fixed the seat and back in place temporarily so that they could be adjusted to suit the clients expectations. I based their positions on my own assessment of the posture and comfort, and I am pleased to say that the configuration suited the needs of the client. We agreed on a price, and a deposit set the project in motion.

The first thing was the production of a full-size working drawing. Even though I had the mock-up, which was made using a drawing that could be modified if changes were necessary, I felt that an accurate drawing on white melamine board would give me more control of the progress of the chairs. It could be used to double-check dimensions and the angles of the seat and back. As with many of my previous pieces, the working drawing remained on my bench for the duration of the project. The drawing was followed with the compilation of a cutting list.

Planning

I knew from the outset that these chairs were going to take a long time to make as this had been a major consideration in the costing process. I started working on the seats and backs in parallel with another project on the assumption that once the laminations were glued up and in the press, they could be left in there for eight hours. This could be done first thing in the morning, leaving the rest of the day for the project in hand. I sourced a supply of high quality 1.5mm (1/16in) quarter-cut, French oak (Quercus robur) constructional veneer from Capital Crispin Ltd in London (Tel.: 020 8525 0300). It was perfectly cut and had no trace of the tearing that is quite common with thick veneers. I had previously worked out how much veneer was needed and bought enough bundles for the project. From the number of leaves in each bundle I knew that I had a small surplus if anything went wrong.

Veneer cutting

Ten layers of veneer would produce the 15mm (9/16in) of thickness required for the seats and backs. The seats however, were deeper than the width of the leaves of veneer, so I had to edge joint them to obtain the required dimension. Fortunately, this was not the case with the backs. Cutting show veneers is very often carried out with a knife or scalpel but this is not so efficient for constructional veneers. I decided instead to use the dimension saw on my Felder combination machine. With a trapezoidal tooth blade and a spelch board fixed down onto the sliding table, I was able to cut through the thickness of a bundle of veneers both across and along the grain. I started by placing a bundle of sixteen leaves onto the sliding table, holding them down with a piece of board material and the cam clamp that fits into the tee slot. Strips of masking tape were used to hold the packs together so that the falling pieces behaved as one. The sawn ends were then used as a reference against the fence of the sliding table to square up the long grain edges. These were then planed on the surface planer using a spring loaded feather board to hold the pack against the fence. The feather board is held down onto the infeed table with a very strong magnet.

Edge jointing

It is quite common to use perforated paper tape when show veneers are edge jointed. This can then be sanded off after the veneers have been laid. In the case of edge jointing for laminations, this method would not work. Instead, I glued the edges and held the joint together with masking tape, which was easily removed once the bond had been made. Once again, I used my dimension saw to cut the rectangles of each layer to size, so that I could control the alignment of the edges of the pack of ten layers before they were glued and placed in my vacuum Bench Press.

I used West System epoxy resin, slightly thickened with colloidal silica, to bond the layers together. The slow setting combination gives a long open assembly time while the adhesive is applied with a disposable foam roller. This has been my choice for laminating for quite some time, the reason being that the resin bonds and cures in eight hours, and there is no water to dry out, resulting in no distortion once the pack is removed from the mould. After laying the first set, I realised that I could get a set into the press when I first went into the workshop in the morning and a second set in the evening to be left in overnight. This cut down the time for eight seats and eight backs from sixteen days to just eight days.

Reference edge

Dimensioning the laminated components to size was carried out using the sliding table on my saw. The components were held down with masking tape and the edges of the moulds were used to transmit their accuracy to the first cut on both the seats and backs. This combination was then held against the fence on the sliding table and fed through the saw. The first reference edge was cut across the grain to establish the sides of the seats - this was carried out on all eight seats. The reference edge was then placed against the sliding table fence and the seat was raised into position with a block so that the long grain of the front edge was as near square as possible to the vertical plane of the saw blade. The sliding stop on the fence completed the combination so that the second edge could be cut on all eight seats. The third cross grain edge was cut using the rip fence and the final long grain edge was cut as previously on the sliding table.

Backs

The backs were dimensioned starting with a long grain edge fed through the saw against the rip fence. The second parallel edge was also cut with this method but without the support of the mould. The top and bottom edges were finally cut using the sliding table and a block positioned underneath in the same way as that for the seats. Although there was a little breakout on the underside of the cross grain cuts, this would not be a problem as the edges were to be rounded off at a later stage.

Click here for: Part 2


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Dining Chairs , Robert Ingham , Chairs

"The chairs should not have any wow factor. As a designer, I had never been asked to understate a design before."

Diagrams Click an image to enlarge


Layers and laminated components for seats and backs


Laminating using the Bench Press