SECTION III.
Of the manner of oil gildings and the preparation of fat oil.
THE gilding with oil is the moileafyand cheap, as well as moil durable kind ; and, therefore, is moftly applied to common purpofes. It is performed by cementing the
gold to the ground, by means of fat oil. The preparation of which is, therefore, previoufly neceflary to be known; and may be much better-managed in the following manner, than by any method hitherto taught, or commonly pradtifed.
“ Take any quantity of linfeed oil; and “ put it into an earthen, or any other veflel of “ a broad form : fo that the oil may lie in it “ with a very large furfacej but the propor-
“ tion fhould be fb limited that the oil may be “ about an inch thick in the veflel. The earthen “ pans ufed for milk in the forming cream for “ butter are very well accommodated to this “ purpofe. Along with the oil as much water fhould be alfo put into the veflel, as will <c rife fix inches or more above the bottom.
“ Place it then, with the oil fwimming on “ the water, in any open place where the fun “ and rain may have accefs to it; but where “ it may be as free from receiving duft and “ filth as poflible. Let it Hand in this condi- “ tion, ftirring it on every opportunity, for “ five or fix weeks, or till it appear of the <c confiftence of treacle. Take it then from “ off the water, into a phial, or bottle of a “ long form, or what is better, into a feparat- “ ing funnel, fuch as is ufed by the chemifts, “ and there draw- off the remainder of the ** water. Place it afterwards, being in the long “ bottle or phial, in fuch heat as will ren- ’ ** der it perfectly fluid; and the foulnefles it “ may contain will foon fubfide to the bot- •* tom j when the clear part mart be poured off j and the remainder drained through a “ flannel, while yet water, and will then be ** fit for ufe.”
It is to be obferved that this method is only pradticable in fummer: as the fun has not fufficient ptower in winter to produce a due change in the oil.
This method differs from that commonly pradtifed, in the addition of the water; which fuffers the foulnefs to feparate from the oil and fink to the bottom, where it remains without being again mixed with the oil every time it is ftirred, as is unavoidable where no water is ufed : and likewife greatly contributes to bleach the oil, and improve it in other re- fpe&s.
The bell previous preparation of the piece to be gilded, if it have not already any coat of oil paint, is to prime it with drying oil mixed with a little yellow oker; to which, alfo, a very finall proportion of vermilion may be added : but where greater nicety and perfection is required in the work, the wood fhould be firfl rubbed with filh Ikin; and then with Dutch rulhes.
This priming being dry, the next part of thi o'eration is the fizing the work; which may be done, either with the fat oil alone; (but diluted with drying oil, if too thick to be worked without) or with fat oil and the japa- ner’s gold fize, (of which the preparation is below taught) either in equal quantities, or in any lels proportion with refped to the gold fize. The difference betwixt the ufe and omiffion of the gold fize, in this way of gilding, lies in two particulars; the one is, that the fizing dries fafler according to the proportion of the quantity of the gold fize to the fat oil, and is con- fequently fo much the fooner fit to be gilded; the other is, that the gilding is alfo rendered, in the fame proportion, lefs fhining and glofly; which is efteeraed a perfection in this, lund of 3 gilding: gilding: though, taking away the prejudice of fafhion, I fhould think the mod fhining the moft beautiful j and of the ftrongeft effeft. ‘
The fat oil, or the compound of that and th.e gold fize, muft be ground with fome yelldw okerj and then, by means of a brufh, laid thinly over the work to be gilt: but, in doing this, care muft be taken, to pafs the brufh into all the hollows and cavities, if the fubjeCt be carved, or have any other way projecting parts. For where the fize fails to be laid dn, the gold will never take, till the work be again repaired by paffing over die defective places with frefti fize : which fhould be avoided as much as pof- fible. Where great perfection is required, the gold fhould not be laid on the firft fizing; but that being fuffered to dry, the work fhould be again fized a fecond time: and fbme who are very nice even proceed to a third.
The work being thus fized muft be kept till it appear in a proper condition to receive the gold : which muft be diftinguifhed by touching with the finger $ when, if it appear a little adhefive or clammy; but not fo as to be brought off by the finger, it is in a fit condition to be gilt: but if it be fo clammy as to daub or come off on being touched, it is not fufficiently dry, and muft be kept longer : or if there be no elamminefs or fticky quality remaining, it is too dry, and muft be fized over again before it can be gilt.
When the work is thus ready to receive the gold, the leaves of gold, where the furface is fufficierttly large and plain to contain them, may be laid on, either by means of the fquir- rel’s tail; or immediately from the paper in which they were originally put; a method, that, by thofe who have the proper dexterity of doing it, is found to be much the fimpleft and quickeft, as well as belt, for the perfection of the work. Being laid on the proper parts of the work, the leaves muft then be fettled to the ground, by comprefling thofe, which appear to ^ant it, gently with the fquirrel’s tail or cotton ball; and if any part of the gold has flown off, or been difplaced, fo as to leave a naked or uncovered part, a piece of another leaf, of fize and figure correfpondent to fuch part, muft be laid upon it. Where the parts are too fmall to admit of the laying on whole leaves, or where vacancies are left after laying on whole leaves which are lefs than require others to cover them, the leaves which are to be ufed muft be turned from the paper upon the cufhion {deferibed above amongft the inftruments;) and ' cut, by fcoring over them, with the knife, (above delcribed likewife,) into fuch divifions or flips as may be moft commodioufly laid on the parts of the work to be covered: and then, being feparated, and taken up as they are wanted by means of the cotton wool, to which being breathed upon they will adhere, they muft be laid in the places they are defigned to cover; and gently prefled by the cotton, till they touch every where, and lie even on the ground.
Where the work is very hollow, and fmall pieces are wanted to cover parts that lie deep and out of the reach of the fquirrel’s tail or the cotton, they may be taken up by the point of a fitch pencil (being firft breathed upon) and by that means conveyed to and fettled in their proper place : and thofe who are accuftomed to it ufe the pencil commodioufly for a great part of the work where large parts of the leaves cannot be ufed. '
The whole of the work being thus covered fhould be fuffered to remain till it be dry j and may then be brufhed over by a camel’s hair pencil or foft hog’s hair brufh, to take off from it all loofe parts of the gold.
If after the brufiling any defective parts, or vacancies appear in the gilding, fuch parts mull be again fized; and treated in the fame manner as the whole was before: but the japaner’sgold fize alone is much better for this purpofe than either the fat oil alone, or any mixture.