The pioneer express. [volume] (Pembina, Dakota [N.D.]) 1883-1928, 1894-03-23
THE ,ASEFVL ARTs.
1DEnTAINING TO SCIENCE 4.
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taEing the place Of Iron tor MI kinds
of constitutional, work, sand ia SO large
~ employed In ship building that. the
necessity Of providing soIi,e means Of
making 1t proofagainst the oxidising in
flucnce, Of air. and. water; has become
Imperative Such means ISL Mt hand
In q new elcctro-xincing prOtess. Hlth-
erto the zincing process has been both
expensive and wasteful and difficult
to manage. Articles were dipped in u
bath Of molten zinc, the zfnc-lrOn al0y,
over % per cent of the whole quantity
Of zinc used. This added considerable
to. the cost of galvanizing, and the
large quantity of zinc, usually some
fifteen or twenty tons, which had con-
stantly to bc kept in a molten condition,
entatled heavy expenditure In. fuel.
che question Of temperature hns al-
ways been n source Of serious trouble
lin galvanizing baths. Tie necessary
pickling and hot galvanizing reduced
the strength of wires, aud distorted
and rendered brittle iron and steel Of
small section. Exposure to even the
lowest temperature Of the galvanizing
bath greatly reduced the hardness OF
steel wire Of Il high breaking loud,
and impaired its tensile strength by as
much as from to 10 per cent. 1t
WIS the practice when coating steel
wire TO keep the bath Of molten zinc
ut lis low temperature us possible
and run the wire through at high
rate of speed. The waste of metal from
both these sources was considerable.
The zinc solidiffed rapidly ON the COM
paratfvGly cold wire and was especially
liable to be broken or cracked OH
in bending or twisting, as molten zinc
of low temperature cannot be depended
upon to adhere to steel except after pro-
longed contact. Again, the zinc coat
put on by the hot process was uneven,
and although lin the case of wire and
thin sheets some Of the zinc might be
squeezed off by mechanical means
when leaving the bath, there was more
or less serious loss from this cause.
Much money has been spent In the at
tempt to substitute ordinary electro
zinc plating for galYanizinG; but the ex-
periments have not been successful. as
the process was found to he too slow
and costly. and the zinc coating de-
posted porous, the result being TINT the
acid solution retained in the zinc de-
post set UP a galvanic action. which de-
stroyed the protective coating. and there
was great difficulty in coating articles
of irregular shape. All these troubles
are now at an end. BY the electro
zincing process plates eighteen feet
long can be coated with ease, certainty
and the maximum adhas mess. The
articles are first picked, then passed
through washing tank, and after
ward ,remo owed to the Mating bath by.
means Of m overhead trolley running
on reels. An .electric current is passed
through the pickling bath, SO as to
quicken the process. retain smooth
surface and prevent any reduction IN
tensile strength: The process lis. very
much cheaper than hot galyanlzing,
being about Onehalf in til, case Of
plates, and, from THE reduction in tenn
perature, there Is no distorting or warp
ing of articles Of small Sc ctiOn. -