This is a very interesting read I extracted from Colonial Williamsburg, the rules on Varnishing are written by John Stalker in 1688. It describes in brief out of what your varnish should be made from, how you should prepare your surface, how you should perform the brush strokes and so forth. It may be a little difficult to understand on first read so I advise you to read a couple of times to fully grasp its invaluable piece of advice.
Below is a definition of the main words for tools used.
Varnish: they recommend a 1½ pound cut of seedlac (1½ pounds of an unrefined form of shellac dissolved in a gallon of alcohol).
Pencil: a brush (they recommend camel hair, we usually use china bristle brushes).
Rush: horsetail rush/equisetum is a marshy grass that pulls silica out of the soil and has a very fine abrasive quality. In my mind it compares to anything from 220 to 600 grit sandpaper (each rush is a little different from the last). Its use in the 17th and 18th centuries is well documented.
Gallipot: a small earthenware container.
General Rules to be diligently observed in all manner of Varnishing.
I am very solicitous that your Work should succeed, and therefore take all imaginable care to guide you, so that you cannot possibly miscarry; and in order thereunto shall propose rules and general Cautions,, which I desire you would have always in mind, and call them to your assistance in all your undertakings.
1. Therefore let your wood which you intend to varnish be close-grained, exempt and free from all knots and greasiness, very smooth, clean, and well rush’t.
2. Lay all your Colours and Blacks exquisitely even and smooth; and where ever mole-hills and knobs, asperities and roughness in colours or varnish offer to appear, with your Rush sweep them off, and tell them their room is more acceptable to you than their company. If this ill usage will not terrifie them, or make them avoid your work, give them no better entertainment than you did before, but maintain your former severity, and with your Rush whip them off, as often as they molest you.
3. Keep your work always warm, by no means hot, which will certainly blister or crack it; and if that mischance through inadvertency should happen, tis next to irreparable, and nothing less than scraping off all the varnish can rectifie the miscarriage.
4. Let your work be thoroughly dry, after every distinct wash; for neglect in this point introduces the fault again, of which we warned you in the second rule, That your varnish should not be rough and knobby.
5. Let your work lie by and rest, as long as your convenience will admit, after tis varnished; for the better will your endeavors prove, the longer it stands after this operation.
6. Be mindful to begin your varnishing stroak in the middle of the table or box that you have provided for that work, and not in full length from one end to the other; so that your brush being planted in the middle of your board, strike it to one end; then taking it off, fix it to the place you began at, and draw or extend it to the other end; so must you do till the whole plane or content be varnished over. I have reasons too for this caution, which if neglected, has several faults and prejudices attending it; for if you should undertake at one stroak to move your Pencil from end to end, it would so happen that you would overlap the edges and mouldings of your box; this overlapping is, when you see the varnish lie in drops and splashes, not laid by your brush, but caused by your brushes being at the beginning of the stroak overcharg’d and too full of varnish, and therefore we advise you to stroke your pencil once or twice against the Gallipot, to obstruct and hinder this superfluity; small experience will discover these mistakes.
[Rules 7-10 concern polishing finishes with tripoli, which we do on occasion, but we’ll reserve a discussion of these for a future post]
To conclude, let this Chapter be well studied, and remember, that without it you cannot regularly or safely perform the task; This is the Common-place-book, to which I shall continually refer you; and if you will prove negligent and remiss in this particular, I shall prophesie, that nothing can so infallibly attend you as Error and Disappointment.
Horsetail rush (Equisetum), a common historical abrasive, which, used on edge, results in a surface similar to that produced by 220 to 600 grit modern sandpapers. Here it’s effects are shown on a varnished piece of walnut.