I left an inlaid chair in pieces a few days before Christmas. Somehow since then I haven't found much inclination to keep this occasional journal up-to-date, although there has been time. But as February begins, today (Sunday) is grey and rainy; this morning's southeast wind with light drizzle has switched to southwest, with occasional heavy showers. It's five o'clock, getting dark, and the planned walk at Burgoyne is not going to happen. Other planned things didn't happen today either, but some unplanned ones did: I broke the Toyota's back side window whilst reversing down the hill (caught by cedar branch), and spent time repairing it (temporarily) with black duct tape and heavy vinyl. The repair (from a distance) looks OK. Pelican Rick once said that "Temporary's permanent", so I suppose one might as well make a half-ways decent job of temporary repairs.
Briefly, back to the chair:
There we are - back together. In fact it took a good deal of fiddling and adjustment to get to this point: all the broken pieces and joints had to be throughly cleaned of old glue, grease and dust, and fresh clean wood exposed in the break.
First the arms and arm supports were re-assembled and re-screwed. Then the remaining back pieces, with pins inserted as needed, and finally the parts were glued together with epoxy. (I've recently taken to using a micro-pinner (shame) to secure difficult joints in the correct alignment while clamping. Micro-pins are invisible and immediate, and don't cause joint-movement when driven (pneumatically)).
The joins were first wetted with plain resin, and then a thickened pigmented resin was used to complete the bond. Two clamps were used to bring the back together, and a third clamp (diagonally placed) pulled the top rail slightly forward to close the slightly open joints caused by the awkwardly placed back clamps. This all took a while, but epoxy, though messy, is forgiving.
After the glue had cured by the stove for a day, the clamps were removed, and the more difficult work of cleaning up and finishing commenced. The registration of glued breaks is rarely perfect, and some smoothing and sanding will inevitably be needed. This naturally removes the finish, which will then have to be carefully matched to the original. (Usually the revealed wood is lighter in colour than the aged and patinated finish. However some woods, notably rosewood and some walnuts, can be considerably darker than their exposed and bleached surface; whereas it's not hard to make light woods darker, it's very much trickier to make dark wood lighter.)
Here the areas that need work are clearly visible, and on the plastic-protected seat are some of the tools in use. As well as working on the re-glued joins, there's also the damaged and missing inlay & stringing to repair as well. Missing pieces of the ivory stringing are being replaced by burning in with a slightly lighter coloured shellac stick.
Once the lighter-coloured areas of mahogany around the joins are smoothed down and made fair, any filling of cracks, gaps, chips &c. &c. can be done; for small areas I use shellac stick approximating the finished colour; for larger areas epoxy resin with a suitable fairing filler and pigment, usually some combination of Vandyke Brown, Burnt Umber and a pinch of Lamp Black. It's best to actually mix up a sample and let it set, as the colour can change significantly as the epoxy cures and hardens (quick-cure epoxy is good for samples, but does not do so well for the final filler - it doesn't seem to sand cleanly.
Colouring and matching the wood is mostly a matter of building up layers of stain, pigment and shellac and blending them with the existing finish: for this repair I used a couple of coats of brown spirit stain (leather dyes work well, obtainable at Tandy's leather shops). The advantage of spirit stains is that they dry more-or-less instantaneously, they mix well, multiple coats may be used to darken or modify the shade, and, most important, if they are the wrong colour or too dark they can be (largely) removed with alcohol.
After bringing the "new" wood to a close approximation of the existing finish colour, we (I) can set about re-creating the original finish – which is probably some compound of shellac, oil, wax, dirt, soot, grease, restorer, reviver, patented french polish ("Instant Shine!! Easy to Apply!! No Skill Needed.) Well.
In the end you use what it takes, but you can do most jobs with button shellac and earth pigments - again, Vandyke Brown, Burnt Umber, and black, with some reds or yellows to change the tone as necessary. This chair is very much on the black side. Use a small brush to make a little puddle of button shellac on a suitable "palette" - the inside of old yoghurt lids works well, since they are plentiful (in this house, anyway) and white, which shows the mixed colours clearly. Then add the basic brown pigment, adding other shades as needed until until you have a close match. What you now have on your yoghurt lid is essentially a paint, fairly (or totally) opaque; this method does NOT work for newer and clearer finishes, but it does very well indeed for antiques with a heavy and obscuring build up of old finish. Each layer is sanded with 280 grit garnet paper, with a little raw linseed oil to lubricate it; when the match and finish and blending are good, then a little clear button shellac can be applied with a brush or pad - but be careful not to drag the pigmented finish. Finally a rub down with 0000 steel-wool, and to finish a couple of coats of wax polish.
Somehow I don't have a photo of the finished chair. Suddenly iPhoto shows it's a day or two before Christmas and there are pictures of Norah, Addi and I cutting a tree down in the bush......and then it's photos of Christmas Eve, and J.'s tortiere and Greg's crab with garlic butter and lemon butter and pickled onions and fresh bread and salads and wine.. ( 'O stop, stop,' cried the Mole in ecstasies: 'This is too much!'.) and I didn't go back to work for two weeks.........
Next: Zadie Smith and the craft of furniture making.