CHAP. V.
Of laquering.
LAQUBRING is the laying either co-loured or tranfparent vamimes on me-tals, in order to produce the appearance of a different colour in the metal j or to preferve it from ruff and the injuries of the Weather.
Laquering is therefore much of the fame nature with japanning, both with regard to the principles and practice j except that no opake colours, but tranfparent tinges alone, are to be employed.
The occafions on which laquering is now in general ufed are three : where brafs is to be made to have the appearance of being gilt: where tin is wanted to have the refemblance of yellow metals : and where brafs or coppér locks, nails, or other fuch matters, are to be defended from the corrofion of the air or moifture. There was indeed formerly ano-' ther very frequent application of laquering ; which was colouring frames of pictures, &c. previoufly filvered, in order to give them the effeCt of gilding ; but this is now greatly dif- ufed. Tnefe various intentions of laquering require different compofitions for the effectuating each kind ; and as1 there is a multiplicity of ingredients which may be conducive to each purpofe, a proportionable number of recipes have been devifed, and introduced into practice j elpecially for the laquering brafs work to imitate gilding ; which is a confiderable object in this kind of art j and has been improved to the greateff: degree of perfection. I (hall, however, only give one or two recipes for each } as they are all which are neceffary ; the others being either made too complex by ingredient» not eflential to the intention, or too coftly by the ufe of fuch as are expenfive ; or inferior in goodnefs, from the improper choice or proportion of the component fubftances.
The principal body or matter of all good laquers uled at prefent is feed-lac; but, for coarfer ufes, refin, or turpentine, is added; in order to make the laquer cheaper, than if the feed-lac, which is a much dearer article, be ufed alone. Spirit of wine is alfo confequently the fluid or menftruum of which laquers is formed; as the ethereal oils will not difiolve the feed-lac: and it is proper that the fpirit fhould be highly rectified for this purpofe. As it is feldom prac- * ticable, neverthelefs, to procure fuch fpirits from the fhops, it will be found very advantageous to ufe the method above given for de- phlegmating it by alkaline falts j but the ufe of the alum, dire&ed in that procefs, muff not be forgotten on this occafion; as the effedt of the alkaline fait would otherwife be the turning the metal of a purplifh inftead of a golden colour, by laying on the laquer.
The following are excellent compofirions for brafs work which is to refemble gilding.
“ Take of turmeric ground, as it may be had “ at the dry falters, one ounce, and of faffron “ and Spanifh annatto each two drams. Put “ them into a proper bottle, with a pint of “ highly rectified fpirit of wine; and place “ them in a moderate heat, if convenient, <c often fhaking them, for fcveral days. A “ very ftrong yellow tindture will then be ob“ tained; which mufl: beftrained off from the • “ dregs through a coarfe linnen cloth: and <*« then, being put back into the bottle, three “ ounces of good feed-lac powdered grofsly “ mull be added, and the mixture placed a“ gain in a moderate heat, and diaken, till die “ feed-lac be difiolved; or at lead fiich part of “ it as may. The laquer mult then be drained as before j and will be fit for ufe; but mud <c be kept in a bottle carefully dopt.
“ Where it is defired to have the laquer “ warmer or redder than this compofition may “ prové, the proportion of the annatto mud be increafed j and where it is wanted cooler, ** or nearer a true yellow, it mud be dimi- ** niflied.”
The above, properly managed, is an extreme good laquer j and of moderate price : but the following, which is cheaper, and may be made where the Spanilh annatto cannot be procured good, is not greatly inferior to it.
** Take of turmeric root ground one ounce, ** of the bed dragon’s blood half a dram, Put them to a pint of fpirit of wine, and ** proceed as with the above.” '
By diminifhing the proportion of the dragon’s blood, the vamifli may be rendered of a redder, or truer yellow cad.
Saffron is fometimes ufed to form die body of colour in this kind of laquer, indead of the turmeric; but though it makes a warmer yellow, yet the dearnefs of it, and the advantage which turmeric has in forming a much drorrger tinge in fpirit of wine, not only than the saffron, but than any other vegetable matter hitherto known, gives it the preference. Though being a true yellow, and confequently not fuf- ficiently warm to overcome the greenilh call of brafs, it requires the addition of fome orange coloured tinge to make a perfect laquer for this purpofe.
Aloes and gamboge are allb fometimes uled in laquers; but the aloes is not neceflary where turmeric or falfron are ufed; and the gamboge, though a very ftrong milky yellow in water, affords only a very weak tinge in Ipirit of wine.
The varnilh for tin may be made as follows.
“ Take of turmeric root one ounce, of dra- “ gon’s blood two drams, and of fpirit of wine “ one pint. Proceed as in the former.’*
This may, like the former, have the red or yellow rendered more prevalent by the increasing or diminilhing the proportion of the dragon’s blood. Where a coarfer or cheaper kind is wanted, the quantity of leed-lac may be abated j and the deficiency thence ariling fupplied by the fame proportion of refin.
The laquer for locks, nails, &c. where little or no colours is defired, may either be feed- lac varnilh alone as prepared above, or with a little dragon’s blood : or a compound varnilh of equal parts of feed-lac and relin, with or without the dragon’s blood.
The manner of laying on the laquer is as follows.
Firft let the pieces of work to be laquered be made thoroughly clean; which, if they be new founded, this muft be done by means, of aqua fords. Being ready, they mull be heated by a fmall charcoal fire in a proper vefiel, or any way that may be moft convenient: the degree mull not be greater than will admit of their being taken hold of without burning the hand. The laquer muft then be laid on by a proper brufli in the manner of other vamifhes j and the pieces immediately fet again in the fame warm fituation. After the laquer is thoroughly dry and firm, the fame operation muft be renewed again for four or five times, or till the work appear of the colour and brightnefs intended. For very fine work, feme ufe a Ids proportion of feed-lac; which occafions the laquer to lie evener on the metal: but in this cafe a greater number of coats are required ; which multiplies the proportion of labour ; though, where the price of the work will allow for fuch additional trouble, it will be the more perfect for it.
The laquering tin may be performed in the fame mariner, as is here directed for brafs: but being for coarfer purpofes lefs nicety is ob- ferved j and fewer coats (or perhaps one only) are made to fuffice; as the laquer is made very red, that the tinge may have the ftronger effedt.
Locks, nails, &c. where l&quer is only ufed in a defensive view, to keep them from cor- roding, and not for the improvement of the colour, may be treated in the fame manner: but one or two coats are generally thought fuf- ficient. Though where any regard is had to the wear, the coats of laquer or varnifh fhould always be of a due thicknefs, when they are to be expofed to the air; otherwife, the firft moifl weather makes them chill, and look grey and mifty, in fuch manner, that they are rather injurious than beneficial to the work they are laid upon.