The weekly Panola star. [volume] (Panola, Miss.) 1857-1881, 1870-10-15
Clements and How 10 Use Them.

A great deal has been written concern.
Ing different cements. and indeed our pc.
riodicals are full OF recipes on this sub.
iect. But (sayB the English MochaRicl, IL
will be found that the information given
Is rather Ia regard 10 the materials used
In compromising these oomonts than In
regard TO the manner Of using them.
And II Ia ubquostionably true that quite
as much depends upon the manner in
which a cement Is applied as upon tho
cement itself. The best cement that ever
was compounded would prove entirely
worthless # improperly applied. We have
hundreds OF recipes for CLUES, pastes, and
cemenls Of different kinds, and yet the
public is constantly on the qui uipe for
now ones, and no more acceptable recipe
can be sent To u popular Journals than
one for n new cement. Now, the truth is,
thst we have ccments which answer eve.
ry reasonable demand, when they are
properly prepared and properly used.
Good common glue will unite two pieces
Of wood go firmly that the 1bers will part
from each other rather than from the CO.
menting material; two pieces Of glass
can be SO Joined that they will part any.
where rather than on the line of union
glass can be united TO metal, metal to
metal, stone 10 stone, and oil 30 strongly
that the Joint will certainly not be the
weakest part Of the resulting mass What
are the rules to be observed In efIecting
thls9
Tho first point that demands attention
is TO bring the cement itself into intimate
contact with the surface TO be united. Ii
glue ia employed, the surface should be
made 30 warm that the melted give will
not be chilled before II has time to effect
a thorough adhesion. The same ia more
eminently true in regard to oements that
are used In q fused state, such as mixtures
Oh resin, shellac, and similar materials.
These mixtures will not adhere 10 any
substance unless the latter has been heat.
ca to nearly or quite the iusing point Of
the cement used. This fact was quite
familiar to those who used sealing wax In
Old days. When the seal was used rapid,
~, 80 ss to become heated, the sealing
wax stuck TO II with q flrmness that was
anpoylng--so much so that the impres.
SION was, in general, destroyed-from the
simple iact that the sealing wax would
rather part in It's own substance than al
inc polnt OF adhesion to the STAMP. Seal.
ing wax, or ordinary electrical cement, Ia A
very good agent for uniting metal 10 glaas
or stone, provided the masses to be united
are made 80 hot as to fuse the cement,
but II the cement is applied to them while
they are cold, 1t viii not stick At ali.
This TACT is well known to those itinerent
vendors OF cement for uniting earthon.
ware. BY heating two pieces of delft 30
thai they will fuse shellac, they are able
to smear them with a little of this pum
and join them so that they will rather
break at any other part than along the
line OF union. But although people con.
SANITY see the operation performed. and
BUY literally of the cement, il will he
found that, in nine cases out of ten. the
cement proves worthless In the hands ii
h purchasers, simply because they do
not know how to use 1t. They are afraid
10 neat a delicate glass or porcelain YES.
sci TO a sufficient degree, and they are an,
10 use too much OF the material, and tho
result Is a failure.
The great obstacles TO the junction al
any two surfaces are air and dirt. TkF
former is universally present, the latter i,
Que TO accident or carelessness. All sur
faces are covered with y thin adherinp
layer OF air, which 1t is difficult to re-
move, and which, although il NAV at frs,
sight appear improbable, bears a relation
to the outer surface of most bodies differ,
cnt from that maintained by the air d q
tew lines away. The reality of the TX.
istencc OF This sohering layer of air /.
well known to all those who are familiar
with electrotype manipulation. 1t Ia also
seen In the case of highly polished metals
which may be immersed In water withoui
becoming wet. Unless this adherinu
layer OF air is displaced, the cement can.
o adhere 10 the surface to which il ia
applied, simply because II canno, come In.
TO contact with II. The most efficient
agent In displsoing this air ia heat
Metals warmed to a point a little aheve
WV, become mstsntly and completely
wet when immersed In water. Hence,
for dement's that are used in \ fused con.
dition, heat is the most efficient means Of
bringing them In contact with the sur.
Aces to which they are 10 be applied, In
the case of glue, the adhesion Is best NJ.
tanned by moderate pressure and friction.
Another very important point is to use
as little cement as possible. When the
surfaces are separated by a large mass of
cement, we have 70 depend upon the
strength OF the cement itself, and not
upon its adhesion TO the surfaces which
II is used TO Join; aud, in general, cements
are comparatively brittle.