A MANUAL OF
MENDING AND REPAIRING
WITH DIAGRAMS
BY
CHARLES GODFREY LELAND
NEW YORK
DODD, MEAD AND COMPANY
1896
COPYRIGHT, 1896,
BY DODD, MEAD AND COMPANY.
BURR PRINTING HOUSE, FRANKFORT AND JACOB STS., N. Y.
CONTENTS
PAGES
INTRODUCTION vii-xxiii
MATERIALS USED IN MENDING 1-11
MENDING BROKEN CHINA, PORCELAIN, CROCKERY, MAJOLICA,
TERRA-COTTA, BRICK AND TILE WORK 12-32
MENDING GLASS, TOGETHER WITH SEVERAL ALLIED PROCESSES:
APPROVED CEMENTS--SILICATE OF SODA 33-49
WOOD-SHAVINGS IN MENDING AND MAKING MANY OBJECTS--ORNAMENTAL
WORK OF SHAVINGS--MARQUETRY--REPAIRING
PANEL PICTURES WITH SHAVINGS 50-57
REPAIRING WOODWORK 58-85
ON REPAIRING AND RESTORING BOOKS, MANUSCRIPTS, AND
PAPERS, WITH DIRECTIONS FOR EASY BINDING AND
PAPER-MENDING--BOOK-WORMS--THE RAVAGES OF
BOOK-WORMS 86-120
PAPIER-MÂCHÉ: REPAIRING TOYS--MAKING GROUNDS FOR
PICTURES AND WALLS--CARTON-CUIR AND CARTON-PIERRE 121-133
MENDING STONE-WORK: MOSAICS--CERESA-WORK--PORCELAIN
OR CROCKERY MOSAIC 134-142
REPAIRING IVORY 143-155
REPAIRING AMBER: HOW TO PERFECTLY RE-JOIN BROKEN
AMBER, AND TO IMITATE IT--HOW TO MELT AMBER IN
FRAGMENTS TO A SINGLE BODY 156-158
INDIARUBBER AND GUTTA-PERCHA: MENDING INDIARUBBER
SHOES AND MAKING GARMENTS WATERPROOF, WITH
OTHER APPLICATIONS 159-168
MENDING METAL-WORK OR REPAIRING BY MEANS OF IT:
FIREPROOF CEMENTS, WITH IRON BINDERS 169-182
REPAIRING LEATHER-WORK: TRUNKS, SHOES, OR IN ANY
OTHER FORMS--JOINING STRAPS--MAKING CHEAP
SHOES 183-198
TO MEND HATS, BLANKETS, AND SIMILAR FABRICS BY
FELTING 199-201
INVISIBLE MENDING OF GARMENTS, LACES, OR EMBROIDERIES 202-205
MENDING MOTHER-OF-PEARL AND CORAL 206-209
RESTORING AND REPAIRING PICTURES 210-230
GENERAL RECIPES 231-253
INDEX 255-264
INTRODUCTION
The author of this work modestly trusts that all who read it with
care will admit that in it he has distinctly shown that mending or
repairing, which has hitherto been regarded as a mere adjunct to other
arts, is really an art by itself, if not a science, since it is based
on chemical and other principles, which admit of extensive application
and general combination. It has its _laws_--a fact which has never been
hinted at by any writer, since all recipes for restoration in existence
are each singly inventions made to suit certain cases. This work has
been conceived on a different principle.
A thorough knowledge of this art of repairing, mending, or restoring
various objects is of very great value, since there is no household
in which it is not often called into requisition. In the kitchen or
drawing-room, in the library and nursery, there are daily breakages,
of which a large and needless proportion are losses, simply because
such a man as a general mender, who is accomplished in _all_ branches
of the art, does not exist. And, what is more, it is equally true that
no one has ever realised to what a vast extent mending and saving may
be carried, with a little expenditure of time, practice, and money,
by any intelligent person who will devote serious attention to it.
Within a comparatively few years discoveries in science or in nature
have enlarged the ability of the mender to an extraordinary extent--I
need only mention the applications now made with silicate of soda,
celluloid, gutta percha, and glycerine to confirm what I say--so
largely, indeed, that only the accomplished technologist and chemist
is really aware of what can be done in general repairing compared to
what was possible only a few years ago. I believe that there are few
thoroughly practical persons (and, I may add, few who take an interest
in art in any form, or even in books) who will read this work without
deep interest, and without acquiring information of such value that in
comparison to it the cost of the book will seem a trifle.
Though mending or restoring is a subject which in some form comes
home to and concerns everybody, and which it is assuredly everybody’s
interest to understand, this is, I believe, the first book in which
its application to a _great_ variety of wants has been made, and that
in such a clearly co-ordinated manner, and according to such a simple
principle, that whoever reads it can have no difficulty in mending any
object, even though it be not described here. In all works of the kind
which I have seen the recipes for repairing have been given simply
according to their _subjects_, without any view to general principles
of application, and a great proportion of these were in turn simply
copied from old books of miscellaneous “receipts,” or newspapers in
which every so-called new discovery is announced as infallible, or
as if it had been tried and tested to perfection. That I have not
recklessly accumulated in this fashion all kinds of _recipes_ to fill
my pages will appear very plainly to every chemist or technologist,
who will perceive that, proceeding from a comprehensive table of
generally recognised and long-tested bases of cements, I have given
deductions and combinations scientifically agreeing with their laws and
with experiment. The true object of giving a great number of recipes
has not been solely or simply to supply the house-keeper or mechanic
with instructions for certain repairs, but also to suggest to the
technologist and inventor new ideas and applications. Thus, when we
know that given proportions of zinc in powder, silicate of soda, and
chalk form a strong cement, resembling zinc, it is as well to suggest
that this may be varied by employing other metals and substances, such
as bronze-powders and mineral oxides, to be always preceded by a little
experiment. I venture to say that any intelligent person who masters
this work can, on this hint, make for himself innumerable inventions;
and I am sure that there is not the editor of a single technological
journal who will not testify to the fact that every year a great many
patents are taken out and fortunes made from recipes which are neither
so scientifically combined nor practically useful as those which I here
give. That there are fortunes still to be made is abundantly proved by
the fact that there are very few people, comparatively speaking, who
know where to get or how to make waterproof glue, or how to mend with
it, neatly and durably, shoes, umbrellas, and many rents in garments;
how to unite a broken strap; mend, by felting, torn hats; rehabilitate
perfectly worm-eaten and torn-away paper; restore decayed broken wood;
or mend, in fact, anything except with common glue or mucilage--both
of which soon give way and crack or melt. So long as such general
ignorance prevails, just so long there will be an opportunity for
the inventor to make and sell cements, and for the repairer to find
employment.
I call special attention to the fact that this book contains no merely
traditional, untested recipes which have been simply transferred from
one Housekeeper’s Manual to another for generations. Where I have not
been guided by my own personal experience--which is, I venture to say,
not very limited--I have either followed truly scientific works, such
as the three hundred volumes of the Chemical-Technical Library of A.
HARTLEBEN; or, when citing from older authors, have invariably given
recipes which agree with the principles advanced by modern analysts and
inventors. And though not a professor of chemistry, yet, as I studied
it and natural philosophy in my youth under LEOPOLD GMELIN, L. PASSELT,
and Professor JOSEPH HENRY, I trust that I have been sufficiently
qualified to avoid errors in what I have written. In short, that I
have _not_ recklessly accumulated every recipe which I could find, and
that what I give are really trustworthy, will appear plainly to the
chemist or technologist, who will perceive that, proceeding from a
given table of generally recognised and long-tested bases of cements,
&c., I have then given deductions and combinations scientifically
agreeing with their laws and with experiment. My book is not a _pièce
de manufacture_, or of hack-work, but one which is the result of
many years of practical experience in the minor arts and industries,
on which subject alone I have published twenty-two works, without
including pamphlets, lectures, and at least one hundred letters or
articles in leading magazines and newspapers. There is, in short, very
little mending or making described in this book which I have not at one
time or other personally effected, having had all my life a passion for
mending and restoring all kinds of objects, and that scientifically and
thoroughly.
As I have observed, there is in every household continual breakage
of many kinds--“or of the rending which cries for mending”--it is
a matter of some importance that some one in the family should pay
special attention to such matters. How often have I seen very valuable
objects stuck together--anyhow and clumsily--with putty, wafers,
sealing-wax, glue, flour-paste, or anything which will “hold” for a
time, when a perfect cure might have just as well been effected had the
proper recipe been taken to the first chemist. This is equally true as
regards taking ink or stains out of garments, or repairing the latter
perfectly, or mending shoes or indiarubber cloth, or felting worn hats
and many other articles, all of which are treated of in this work.
It is true that everybody is not naturally ingenious, or clever, or
gifted, but all may become _skilful menders_ if they will duly consider
the subject (which requires no hard study) and experiment on it a
little. And here I would seriously address a few words to all who are
interested in education. There is a certain faculty which may be called
constructiveness, which is nearly allied to invention, and which is
a marvellous developer in all children of quickness of perception,
thought, or intellect. It is the art of using the fingers to make or
manipulate, in any way; it exists in every human being, and it may
be brought out to an extraordinary degree in the young, as has been
fully tested and proved. Now, if we take two children of the same age,
sex, and capacity, both going to the same school and pursuing the same
studies, and if one of the two devotes from two to four hours a week
to an industrial art class (_i.e._, studying simple original _design_,
easy wood-carving, repoussé, embroidery, &c.), it will be found--as it
has been by very extensive experiment--that the latter child will at
the end of the year excel the former in _all_ branches of learning;
that is to say, in arithmetic or geography, so greatly does ingenuity
proceed from the fingers to the brain. Now, mending is so nearly allied
to all the minor or mechanical arts, it enters into them so closely,
that it in a manner belongs to and is an introduction to them all.
Like them, it stimulates invention or ingenuity, and is perhaps of far
greater practical utility or direct use. Boys and girls learn very
willingly how to mend, and, from a long experience in teaching them,
I should say that a class with experiments and practical instruction
in what is given in this book should take precedence of all carpentry,
metal-work, joining, leather-work, or any other branches whatever. For
it is _easier_ than any of them, and it is of far more general utility,
as the following pages clearly show. Such teaching would cost next to
nothing for outfit, and would be the best introduction to technical
education of all kinds.
There is an immense amount of breakage in this world, yet, as a French
writer on the subject observes, there are more great artists than good
_menders_; the latter being so extremely rare that proofs of it are
seen in bungling restorations in every museum in Europe, and in the
almost impossibility of finding (out of Italy) men who can perfectly
mend first-class ceramic ware. We see this ignorance in reproductions
of delicate ivory ware coarsely cast in gypsum, and in a vast rejection
and destruction of antiquities in wood, stone, or ceramic ware, simply
because they are most ignorantly supposed to be beyond repair when they
might, with _proper knowledge_, be very easily and cheaply restored,
to great profit. And if the reader will visit the “dead rooms” of
any museum in Europe and then study this book, he will find ample
confirmation of what I say.
And here I would mention that every collector or owner of any kind of
works of art, of _bric-à-brac_, or curiosities, who will master the art
of mending, can find an illimitable field for picking up bargains in
almost every shop of antiquities in Europe, especially in the smaller
or humbler kind. For it is very far from being true that these dealers
know “how to mend everything;” on the contrary, I have often found
them very ignorant indeed of mending, and have frequently instructed
them in it. Thus I now have before me a “Holy Family” of the early
sixteenth century, bas-relief in stamped leather, twelve inches by
eight, for which I paid two francs, but which I might have had for
one, it being utterly dilapidated, and apparently of no value. In two
or three hours I restored it perfectly, and it would now sell for
perhaps a hundred francs. By it hangs a “Madonna and Child,” painted
on a panel, gold ground, fourteenth century, which, including a very
broad and remarkable old frame, I purchased both for twelve francs.
The panel was warped like a sabre, [Illustration], the colour and
_gesso_ ground badly scaled away in many places. It was split in two
pieces; in short, it appeared to be nearly worthless. Now it is in very
good condition, and would be an ornament to any gallery. As regards
repairing ceramic ware or china, glass, and porcelain, art has of late
years made remarkable advances, this kind of mending being the most in
requisition. As for old carved wood, no matter how badly broken it may
be, eaten away by worms, or rotten, or even wanting large pieces, so
long as its original form is evident, it can be _very easily_ repaired
or restored to all its original beauty and integrity, as I shall
fully explain. In this alone there is a vast field for investment or
money-making, because there are annually destroyed almost everywhere
quantities of old wood-carvings; for, being badly worm-eaten, they are
ignorantly supposed to be irreparable. The same may be said of ancient
carved ivories, which are ready to drop at a touch into dust, as were
those from Nineveh in the British Museum, yet which are now firm and
clear. It is also true of the bindings of old books, many of marvellous
beauty, whether of stamped leather, parchment, or carved. Even more
interesting and curious is the repairing or restoring worm-eaten
manuscripts or papers of any kind, or parchment, the easy process of
filling the holes not being known to many bibliophiles. This art is
becoming known in Germany, where it is not unusual to buy an old book
for a mark, rebind it in hard old parchment, repair it generally for
two or three, and then sell it, according to the subject, for several
hundred or thousand per cent. profit.
It is greatly to be regretted that it is so little known, especially
in England, that to repair a few holes or restore a little broken,
crumbling carving it is not absolutely necessary to tear down an entire
Gothic church and build a new one, as is so very generally the case.
There is no stone-work, however dilapidated it may be, which cannot be
mended very perfectly, and that in almost all cases with a material
which sets even harder than the original, as was perfectly shown at the
Paris Exhibition of 1889. Dilapidated stone carved work, of all ages
and kinds, which could be perfectly restored to a degree which even
very few artists suspect, abounds in Italy, where it can be purchased
for a song. The song, it is true, is generally sung to a small silver
accompaniment, but the purchaser may make it golden for himself. For
very few know how to restore a knocked-off nose so that the line of
juncture be not visible; yet even this is possible, as I shall show.
And I may here remark that in all the first galleries and museums of
Europe, without one exception, there is abundant evidence to prove
that, of all the arts, the one of repairing and restoring is the one
least understood and most strangely neglected.
There is hardly a village so small that one man or woman could not make
in it or eke out a living by repairing different objects. In towns and
cities the demand for such work is much greater, for there ladies break
expensive fans and jewellery, and children their dolls and toys, for
mending of which the “rehabilitators” require “much moneys,” especially
in the United States, where prices for anything out of the way are
appalling.
I would therefore beg all people who are gifted with some small
allowance of “ingenuity,” tact, art, or common-sense to consider that
Mending or Restoring is a calling very easily learned by a little
practice, and one by which a living can be made, even in its humblest
branches, as is shown by the umbrella-menders and chair-caners in the
streets. But common-sense teaches that any one who shall have mastered
all that is explicitly set forth in this book ought certainly to be
able to gain money, even largely; for, as I said, the opportunities
of purchasing dilapidated works of art, mending and selling them,
are innumerable, and Restoration is as yet everywhere in its mere
rudiments and very little practised. That which might be a very great
general industry of vast utility, employing many thousands now idle,
only exists in a hap-hazard, casual way, as dependent on other kinds
of work. But to me it appears as a great art by itself, dependent on
certain principles of general application. And when we consider what
is generally wasted for want of proper knowledge of this great art, it
seems to me to be but rational that if we had in London a school for
teaching mending and restoring in all its branches as a trade, with a
museum to show the public, probably to its great astonishment, what
marvels can be wrought by renewing what is old, it would be of great
service to the country at large. A very little reflection will convince
the least visionary or most practical reader that what is wasted or
annually destroyed of valuable old works, which cannot be replaced,
because they are no longer manufactured, if restored, would form the
basis of a great national industry. It has not as yet, however, entered
into the head of any one to conceive this, simply because no one has
ever been educated as a general restorer, but only in a secondary,
supplementary, small way as a specialist, generally as a botcher. And
I maintain, from no inconsiderable knowledge of the subject, that
the best menders and restorers by far are those who understand the
most branches of their calling. The reason for this is plain; it is
because a repairer, when he comes to some unforeseen difficulty--for
example, in mending china--and finds the cements used are not exactly
applicable, he will, if sensible, think of some other adhesive used in
other kinds of work, or other combinations or appliances.
I go so far as to say that an exhibition of specimens showing all that
can be done in mending and restoration in ceramic art, leather, carved
stone, books, carved and wrought wood, castings, metal, furniture,
fans, and toys, would probably serve as sufficient beginning to
establish classes and a school. The objects should, when possible, be
accompanied by a duplicate or photograph showing the condition they
were in before restoration, on the principle of the picture-cleaners,
who amaze the public with such startling contrasts of dirt and
splendour.
How this can all be done will be found in this book, which I venture
to suggest will often be found useful in every family, or wherever
“things” are broken and worn. For the collector of curiosities who
would willingly pick up bargains, I seriously and earnestly commend it
as a _vade mecum_ by means of which he may literally make money in any
shop. For, as I have already said, strange as it may seem, the small
dealers in _bric-à-brac_ are generally very ignorant of all the curious
secrets of restoration, or else they have no time or means to attend to
such work. Again, if the collector has learned what I here teach, he
will often detect restoration allied to forgery in expensive antiques,
guaranteed to be perfect. It has been well observed by M. RIS-PAQUOT,
in his valuable work, _L’Art de restaurer soi-même les Faïences et
Porcelaines_, that it often happens, most unfortunately, that precious
relics whose value is immense, such as the Italian _faïences_ and those
of Palissy or Henri II., come to collections in such a condition, so
pitifully injured, that _de visu_ we cannot buy them because we know
of nobody who can actually restore them, and because this delicate
work requires so much special knowledge. Add to this, that their
great value and rarity disincline us to trust to the first-comer, or
general workman, treasures which he might utterly ruin by clumsiness or
ignorance.
I may add that I seldom walk out in Florence without seeing old worn
_faïences_ for sale for a mere trifle which with a little retouching,
gilding, and firing could be made quite valuable. In such instances
there need be no complaint of destroying the venerable effect and value
of antiquity. In them antique material may be legitimately employed as
a basis for newer work, especially when it is broken away, worn down
to the core, or full of holes. Now, with what this book teaches in his
mind, the artist or tourist will very soon realise, if he be at all
ingenious, or can avail himself of the aid of some friend who has even
a very slight knowledge of art, that he can at a slight outlay purchase
objects which will become very valuable when afterwards restored at
home.
As I can imagine no head of a family, and no dealer in miscellaneous
works of art or any small wares, no provider of furniture or furnisher,
to whom this work will not be a most acceptable gift, so I am very
confident that every traveller who has trunks to mend or broken straps
to join, and every emigrant roughing it in the forests or the bush
of Australia or Canada, may learn from it many useful devices, and
the fact that with nothing more than a small tin of liquid glue and
another of indiarubber he can effect more than could be imagined by
any one who has not studied the subject. On this I speak not without
experience, having found that, both as a soldier and a traveller in the
Wild West of America, my knowledge of mending was of great use to my
friends as well as myself. A perusal of the Index of what is here given
will satisfy the reader that this manual is in fact a _vade mecum_ for
almost all sorts and conditions of men and women, and that there are
none who would not be thankful for it.
A friend adds to these remarks the suggestion that this work may
properly be included among the presents to a bride as an aid to
housekeeping; and it will probably be admitted that it would prove
quite as useful as many of the gifts which are usually bestowed on such
occasions.
I have truly said that, while breaking and decay are universal, there
are literally nowhere any generally accomplished repairers--that is to
say, experts who know and can practise even what is set forth in this
book. Certain menders of broken china there are, of whom the great
authority on fictile restoration, RIS-PASQUOT, declares that none
can be trusted with anything valuable. There are so few needle-women
who can sew up a rent perfectly that a lady “to the manor born” paid
in Rome _two pounds_, or _fifty lire_, for being taught the stitch,
described in this book, by which it can be done. That it was a great
secret to an expert and accomplished needle-woman proves that it
cannot be generally known. A house-furnisher in London doing a large
business once explained to me with manifest pride how he had, by dint
of persuasion and treating, obtained from another what is really one
of the simplest recipes for restoring a brown stain. All of this being
true, it is apparent enough that any accomplished mender and restorer,
lady or gentleman, can hardly fail to make a living by the art; and I
sincerely believe that it is the simple truth that it is set forth in
the following pages so fully and clearly that any one who will make the
experiment can learn from it how to make a living. This is effectively,
in all its fulness, a new art and a new calling, and it is time that it
were established.
It is a great mistake to suppose that manufacturers are necessarily
good menders of what they make. I have found, as have my readers,
that it is not the great watchmaker who oversees the production of
thousands of watches to whom a watch can be most safely trusted for
rehabilitation. For, in nine cases out of ten, it is some extremely
humble brother of the craft, who does nothing but mend in a small
shop, who restores your chronometer most admirably. The same is true
as regards trunks anywhere out of England, since in Germany and France
anything of the kind is invariably botched with incredible want of
skill. This runs through most trades; for which reason I believe that
a really well-accomplished general _mender_, earnestly devoted to the
calling in every detail and resolved to be perfect in it, could ere
long repair better than most manufacturers, since the latter, in these
days, all work by machinery or by vast subdivision of labour, and not,
so to speak, by hand. But all repairing _must_ be by hand. We can make
every detail of a watch or of a gun by machinery, but the machine
cannot mend it when broken, much less a clock or a pistol!
The value of this book will appear to any one who knows how little
really good repairing there is in Europe. Since writing the foregoing
pages I have gone through the galleries of the Vatican and many other
museums, and been amazed at the coarse, ignorant, and bungling manner
in which the _great majority_ of antique statues and other objects of
immense value have been mended up. There is in most cases no pretence
whatever to conceal the lines of repair, and when this has been
attempted it has failed through ignorance of recipes and instructions
which may be found in this work.
A MANUAL OF
MENDING AND REPAIRING
MATERIALS USED IN MENDING
“_There are full many admirable and practical recipes_
(Hausmitteln), _which are often known only in certain
families_.”--Die Natürliche Magie. By JOHANN C. WIEGLEB, 1782.
The art of mending or of repairing may be broadly stated as being
effected, firstly, by mechanical processes, such as those employed by
carpenters in nailing and joining, in embroidery with the needle, and
in metal-work with clumps, or soldering; and, secondly, by chemical
means. The latter consist of _cements_ and _adhesives_, which are,
however, effectively the same thing. This glue, or gum, is an adhesive
or _sticker_; that is, a simple substance which causes two objects to
adhere. The same, when combined with powder of chalk or glass, would
be a CEMENT. This latter term is again applied somewhat generally and
loosely by many, not only to all adhesives, but also more correctly to
all soft substances which harden, such as Portland cement, mortar, and
putty, and which are often used by themselves to form objects, such
as “bricks” and castings; but these latter, having also the quality of
acting as adhesives or stickers, are naturally regarded as being the
same.
As will be speedily observed in the great number of recipes for
mending which will be given in this book, there are many which occur
frequently in different combinations; therefore it will be advisable
and indispensable for those who wish to master mending as an art to
indicate these as a basis.
As SIGMUND LEHNER has observed in his valuable work on _Die Kitte- und
Klebemittel_, there have been such vast numbers of recipes published
of late years for adhesives in various technological works, that the
combination of the usual materials depends almost on the judgment of
the experimenter, and every practical operator will soon learn to make
inventions of his own. These materials, according to STOHMANN, may be
classified as follows:--
I. Those in which OIL is the basis.
II. Resin or pitch.
III. Caoutchouc (indiarubber) or gutta-percha.
IV. Gum or starch.
V. Lime and chalk.
LEHNER extends the list as follows into adhesives, or cements:--
I. For glass and porcelain in every form.
II. For metals not exposed to changes of temperature.
III. For stoves and furnaces, or objects exposed to
heat.
IV. For chemical apparatus and objects exposed to
corrosive liquids.
V. Luting or cements, to protect glass or porcelain
vessels from the action of fire.
VI. Cements for microscopic preparations, for filling
teeth and similar work.
VII. Those for special objects, such as are made of
tortoise-shell, meerschaum (ivory), &c.
OILS are divided into those (such as olive) which never become hard,
and the linseed, which in time dries into a substance like gum. The
latter combined with a great variety of mineral substances, such as
plumbago, calcined lime, magnesia, chalk, red oxide of iron, soapstone,
or with varnishes, forms insoluble “soaps,” which, as cements, resist
water. They require a long time to _set_ or become hard.
RESINS and GUMS include a great number of substances, such as resin or
hard pitch, which is distilled from pine-trees; shellac, mastic, elemi,
copal, kauri gum, amber, gum arabic, dextrine made from flour, the gum
of the peach and cherry, and of many other trees. To these may be added
frankincense and tragacanth, which is less an adhesive than a stiffener
and dresser. Gums are generally rather brittle; this is remedied by
combination with oily substances, volatile oils, or caoutchouc. With
these gums LEHNER includes asphaltum. The defect of such adhesives is,
as he also remarks, that they will not resist _high_ temperatures.
This, however, will apply to most objects.
VARNISH.--This belongs properly to the gums, but is technically
regarded as a separate material. It is gum in solution in turpentine or
spirits. For details vide _Die Fabrikation der Copal- Terpentinöl und
Spiritus-Lacke_, by L. E. Andés; Leipzig, price 5 m. 40 pf.
CAOUTCHOUC and GUTTA-PERCHA are gums which when hard are still elastic,
and resist the action of water. I have read that a perfect imitation or
substitute for them has been made of turpentine, but have not seen it,
though I have met with glue made with oil and turpentine, which very
much resembled them in elasticity or flexibility. Reduced to a liquid
form with ether, benzine, &c., these gums can be kept in a liquid state
for a long time, and then hardened in any form by exposure to the air.
They enter into a very great variety of cements, such as are meant to
be tough or waterproof. Indiarubber is, on the whole, the best, and
gutta-percha the cheapest, for cements.
GLUE.--This is made, by boiling, from horns and bones; it is
essentially the same as gelatine. It is the most generally known of all
adhesives, and may be modified by certain admixtures to suit almost
any substance. It has the peculiarity that it must always be boiled in
a _balneum mariæ_, or in a kettle in hot water in another kettle. Its
strength is vastly increased by admixture with nitric acid or _strong_
vinegar. On the subject of glue in all its relations, the reader may
consult _Die Leim- und Gelatine-Fabrikation_, or “The Manufacture of
Glue and Gelatine,” by F. Dawidowsky; Vienna, price 3s.
FLOUR-PASTE AND STARCH-PASTE.--These mixtures, though generally
used for weak work, such as to make papers adhere, can be very much
strengthened by admixture with glue and gums. Combined with certain
substances, such as paper, mineral powders, and _alum_, they, when
submitted to pressure, become intensely hard, and resist not only water
but heat, when not excessive. Also combined with varnishes they are
decided resistants. LEHNER speaks of them as if they were perishable in
any condition.
STURGEON’S BLADDER.--With this the bladders of several kinds of fish
are classed. Cut in small pieces and dissolved in spirits it makes a
very strong adhesive, which is mixed with many others.
LIME is the most extensively used cement in the world. Combined
with water it forms mortar. It is united with many substances, such
as caseine or cheese, the white of eggs, and silicate of soda, to
make powerful minor cements. On the subject of lime the practical
technologist should consult _Kalk und Luftmortel_, by Dr. Herrmann
Zwick; Vienna, A. Hartleben, price 3s., in which all details of the
subject are given in full.
EGGS.--The yolk, and more particularly the white, of eggs is sometimes
used as an adhesive, and it enters into many very excellent cements.
For details as to the chemistry and technology of this material consult
_Die Fabrikationen von Albumin- und Eierkonserven_ (A Full Account of
the Characteristics of all Egg Substances, the Fabrication of Egg, and
Blood Albumen, &c.), by Karl Ruprecht; Vienna, A. Hartleben, price 2s.
3d.
NEUTRAL SUBSTANCES, OR BINDING MATERIALS.--Almost any substance not
easily soluble in water, and many which are, from common dust or earth,
or clay, sand, chalk, powdered egg-shells, sawdust, shell-powder, &c.,
when combined with certain adhesives, form cements. This is sometimes
due to chemical combination, but more frequently to mechanical union.
In the latter case the adhesive clinging to every separate grain has
the more points of adhesion, just as a man by clinging with both hands
to two posts is harder to remove than if he held by one.
CASEINE OR CHEESE.--This in several forms, but chiefly of curd in
combination with several substances, but mostly with lime or borax,
forms a very valuable cement. It is also combined with strong _lye_ and
silicate of soda. It must not, however, be too much depended on as a
resistant to water or heat.
BLOOD, generally of oxen or cows, combined with lime, alum, and coal
ashes, forms a solid and durable cement.
GLYCERINE forms the basis, with plumbago, &c., of several cements.
Like oil, it renders glue flexible and partly waterproof. For chemical
details on this subject, vide _Das Glycerin_, by J. W. Koppe, Leipzig.
GYPSUM is combined with many substances to form cements, some of them
of great and peculiar value.
IRON pulverised is the basis of a great number of very durable and
strongly resistant cements.
ALUM may be included among the bases, as it is very important in
several compositions, forming a powerful chemical aid. It is excellent
as aiding resistance to both moisture and heat. For an exhaustive
work on alum consult _Die Fabrikation des Alauns_, &c., by Frederic
Junemann, which should be carefully studied by all who work in cements.
There is a very great number of “indifferent” or minor aids to these,
such as sugar, milk, honey, spirits of wine, water, ochre, galbanum,
tannin, ammonia, feldspar, plumbago, sulphur, vinegar, salt, zinc
(white), umber, bismuth, tin, cadmium, clay, ashes, &c., which are
essential in certain combinations.
DEXTRINE, the gum of flour or starch, or _Leiokom_, much resembles
gum-arabic, but is more brittle. Its adhesiveness depends somewhat on
the manner in which it is dissolved. “It is,” says LEHNER, “prepared
by heating starch which has been moistened with nitric acid; also by
warming paste with very much diluted sulphuric acid.”
WAX, including that of bees as well as paraffine, is used in repairs,
and forms a part of several cements. On this subject consult _Das
Wachs_, or “Wax and its Technical Applications,” by Ludwig Sedna;
Leipzig, 2s. 6d.
SILICATE OF SODA, OR LIQUID GLASS.--This is generally sold in the form
of a very dense liquid. It is prepared by mixing quartz or flint sand
with soda, or more rarely with potash. “It is,” says LEHNER, “a glass
which is distinguished from other glasses by being easily soluble
in water. It is believed to be a very modern invention; but I have
seen Venetian glasses of the fifteenth century which appeared to be
painted with it, or something very similar; and I have found decided
indications of a knowledge of it in two writers of the sixteenth
century, WOLFGANG HILDEBRAND and VAN HELMONT. According to Wagner,
there are three kinds of liquid glass. By itself liquid glass can only
be used for mending glass; but when combined with other substances,
such as cement, calcined lime, or clay, or glass, in powder, it forms
a body as hard as stone, or a double silicate, which is strongly
resistant to chemical influences.” It occupies the first position as
an adhesive for glass, nor is it surpassed as a cement in solid form.
On this subject vide _Wasserglas und Infusorienerde_, &c., by Hermann
Krätzer; Vienna, 3s.
NATURAL CEMENT, OR HYDRAULIC LIME.--This is familiarly known to all
readers as Portland cement, but it is found of different qualities
in many countries, and is also made artificially. Certain mineral
substances have the quality when powdered and combined with water of
setting hard as stone; hence the name _hydraulic_. I have seen at
Budapest articles of Portland cement made in Hungary which equalled in
appearance fine black slate or marble, and, while much less brittle,
were indeed in every respect more durable and resistant to exposure.
These artificial cements can be largely incorporated with indifferent
substances, such as sand; they, however, require intense baking, and
may in consequence be regarded as a kind of fictile ware.
Portland cement is very thoroughly treated in _Hydraulischer Kalk und
Portland Cement_ (in all their relations), by Dr. H. Zwick.
TRAGACANTH, though called a gum, is properly nothing of the kind, not
being a true adhesive. It is the product of the _Astragalus verus_, a
tree found in Asia. It swells out in water, and softens, but without
dissolving. It is more of a glaze than a paste; hence it is used
extensively by confectioners, bookbinders, or to stiffen laces. It
enters, however, into the composition of several cements.
BREAD may be classed as a material by itself, as it derives certain
peculiar virtues from the yeast which causes its fermentation. With
certain combinations it becomes wax-like, or hard, and may be used to
advantage in many repairs as well as for modelling. It has the great
advantage of being easily worked and always at hand.
CELLULOID is treated of in this work under the head of Artificial
Ivory. It is made from gun-cotton and camphor. For full information on
this subject consult _Das Celluloid_, or “Celluloid, its Raw Materials,
Manufacture, Peculiarities, and Technical Applications, &c.,” by Dr.
Fr. Böckmann, Vienna and Leipzig.
POTATOES, peeled and mashed, and kept for thirty-six hours in a mixture
of eight parts of sulphuric acid to a hundred of water, and then dried
and pressed, form a white, hard substance very much like ivory, or,
as one may say, like white boxwood. LEHNER expresses his doubt as to
whether artificial meerschaum pipes were ever made of this substance,
but I have seen them, and can testify that they looked like meerschaum,
and certainly were much harder than _bruyere_, or briar-wood. Whether
they will “colour” I cannot say.
The principle by which potatoes, paper, and many other substances can
be hardened like parchment or horn is curious. Potatoes consist of
about seventy per cent. water and twenty-five per cent. of starch, the
remainder being salts and _cellulose_, which forms cells surrounded by
the grains of starch. “When such a substance is for some time brought
into contact with diluted sulphuric acid, that which results is simply
a contraction of the cells” (_i.e._, a hardening), “or a kind of
parchmenting.” Thus soft paper is converted into parchment.
It is evident that chemistry is as yet in its infancy as regards the
conversion of cellulose by acid into hard substances. Since cotton,
paper, and potatoes all produce by this process different substances,
it is probable that hundreds of organic, or at least vegetable,
substances will all yield new forms.
There is a marked difference between paste made of _starch_ or
_flour_, each having its peculiar merits. The former is principally
prepared from potatoes. To prepare the cement we mix it with a very
little water, stirring it very thoroughly till it assumes a bluish
appearance. A little more hot water is then added, and the mass left
till an opal-like tinge indicates that it has formed. To this then add
hot water _ad libitum_. As it is almost colourless in very thin coats,
it is largely used to glaze and give body or weight to, and often
to simply falsify, woven fabrics, which by its aid seem heavier. To
increase this weight white lead and other substances are used.
To make the best flour-paste, flour should be kneaded in a bag under
water till all the starch is washed away. What remains is a substance
closely allied to caseine, or the white of egg. Combined with lime it
forms a hard cement. A very slight admixture of carbolic acid (also
oil of cloves) will keep paste from souring or decay. This acid has
the property of destroying the growth of the minute vegetation which
constitutes fermentation, just as other strong scents or perfumes are
supposed to disinfect rooms, &c.
A very great number of other ingredients, such as the oxides of lead
or zinc, manganese, baryta, sulphur, sal ammoniac, flint-sand, clay,
salt, ochre, varnish, galbanum, or frankincense, enter into certain
recipes, but those already given may be regarded as constituting by far
the principal portion of all cements in ordinary use.
MENDING BROKEN CHINA, PORCELAIN, CROCKERY, MAJOLICA, TERRA-COTTA, BRICK
AND TILE WORK.
Fictile or Ceramic ware embraces, roughly speaking, all that is made of
clay, or mineral bases or materials, and which is subsequently baked
to give it hardness. The better the material and the more intense the
heat, or the greater the number of bakings to which most kinds are
subjected, the harder and more lasting will they be. The old china ware
which preceded porcelain, a great many specimens of old Roman vessels,
and, for a more modern example, old Italian majolica and Hungarian
wine-pitchers, made all within a century, are as hard as stone. They
chip a great deal before they break, just as agate might do.
TERRA-COTTA is simply earth or clay “baked.” In most of the examples
known as terra-cotta, earth predominates. Pure fine clay well fired is
superior to what is generally called terra-cotta. Neither can we really
class with it articles made of superior Portland cement, of which, as I
have said, I have seen many made at Budapest which were like the finest
hard slate.
Many writers confuse majolica with faïence; others regard the latter
as what we should call crockery, or such ware as ranges between glazed
terra-cotta and porcelain.
MAJOLICA consists generally of terra-cotta covered with a glaze.
A glaze is a fusible substance, we may say a kind of glass, mixed
with colouring matter, which is at the same time a protection and an
ornament. Enamel is glass in fine powder melted, used generally on
metal or by itself. The base of the paint is a substance fusible by
heat which is mixed with colours also fusible. Therefore when the
painting is submitted to heat it melts, adheres, and is permanent.
Glazing, enamelling, and china painting are essentially the same.
Terra-cotta is not difficult to mend. I can best illustrate this by an
example. A friend once gave me a terra-cotta vase from the Pyramid of
Cholula, in Mexico. These are supposed to be of very great antiquity.
This contained a fragment of pottery, probably a sacred relic of ruder
style, and I suppose of far earlier times. The vase, however, had
been broken to fragments, and the owner was about to throw it away as
worthless. I begged it of him. Firstly, I put the principal pieces
together, using, to make them adhere, glue with nitric acid. For finer
work I should have used Turkish cement or the best gum-mastic dissolved
in spirit or fish glue. Piece by piece with care I reconstructed the
whole.
There was wanting, however, one piece about three inches square. I
pasted with great care a piece of paper inside the vase for a _back_,
and then poured on it plaster of Paris liquefied with water. To make
this _set_ hard, the plaster or _gesso_ should be made with burnt
alum-water and dissolved gum-arabic. This exactly supplied the missing
piece.
When it was finished, I filled in all the broken edges and other
cavities with the plaster-paste, which set even harder than the
terra-cotta. The outer colour of the vase was of reddish rusty black.
I painted the whole over with a corresponding colour; that is to say,
I rubbed it in by thumb, which is very different from mere painting.
By cementing and rubbing I so restored the whole that the repair was
hardly perceptible. This process is carried to great perfection in
Italy with broken Etruscan ware.
I may here remark as regards _rubbing in_ oil or water colours, that it
is little known or practised, but it is of great value in restoration
when we wish to produce certain curious antique-looking effects. I
once knew in Rome an artist who had bought for a trifle an old carved
_baule_ or chest. By rubbing in with care on it Naples yellow and brown
shades, and subsequent friction, he had made it look strangely like
old ivory. Mere painting, however skilfully performed, would not have
given it its antique ivory look. The same artist had purchased one or
two common, large, yellowish terra-cotta wine-jars. He drew on them
classical figures, cut out the outlines a little with chisel and file,
and smoothing the figures with sandpaper, also ivoried the whole by
_rubbing in_ colour. This was but a few hours’ work, yet the effect was
startling. What had cost but a few francs would have sold for hundreds.
I should add that with the aid of fine retouching flexible varnish this
process could be very much facilitated. Any one who can draw or paint
at all can try this experiment on any old piece of wood-carving, or
on a common yellow coarse earthenware. Smooth the latter first with
sandpaper, then rub in the colours. The same is applicable to old
carving in marble.
All of these devices are of use to the restorer. As regards restoration
of terra-cotta, the field is wide and profitable. Not only in Italy,
but even in London, we may find for sale broken Etruscan vases or
similar objects for a trifle, which are extremely easy to restore.
These are generally of red or light yellow clay baked. If you have, let
us say, a vase fractured, obtain clay of the same colour--if you cannot
readily get it, take pipeclay--and colour it with a strong infusion of
red or yellow, though this is not necessary if the exterior is black.
Mix the clay well with glue or gum-arabic and alum-water, supply the
missing portions, and let them harden. With a little care and practice,
remarkable restorations may thus be made. I may here add that with
this composition, bottles, decanters, and cups can be coated, which,
when painted or rubbed in, exactly resemble Etruscan or other ancient
pottery. To prevent cracking, they should first be painted with thick,
coarse oil paint mixed with sand or umber, which forms a ground. Let it
dry--the longer the better--and then rub in, thinly, the gum and clay.
There is another composition of _blanc d’Espagne_, or whiting, and
silicate of soda, which sets even harder, but which is a little more
difficult at first to work, which may be used for such restoration.
This can be directly painted on glass for a ground.
_Majolica_ or _Faïence_ can generally be sufficiently well mended with
acidulated glue, but as the latter often communicates a dark stain,
it is better to use for fine ware, or any which is to be used, the
so-called Turkish cement. The best quality of this is made of the
finest quality of gum-mastic dissolved in spirit. It is so tenacious
that in the East gems are frequently directly attached by means of it
to metal, and they will often break sooner than separate from it. Most
chemists have for sale, or will prepare for you, some form of it. The
silicate of potash and whiting can also be supplied by chemists; they
should be mixed with great care, so as to form a medium paste, and then
used rapidly and with skill, because this cement hardens very quickly.
It is, however, a very powerful binder, and sets as hard as glass.