A Method of and Apparatus for Coating Large Surfaces with Copper.
Year: 1893

page_text: 'This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c., Act, 1883), as allowed by
the decision of the Comptroller General of the 15th day of May 1897.
Date of Application, 30th May, 1893-Accepted, 15th July, 1893
COMPLETE SPECIFICATION (AMENDED).
A Method of and Apparatus for Coating Large Surfaces with
Copper.
I, THOMAS SEXTON CRANE, of No. 24 Halstead Place, in the Town of East
Orange, in the County of Essex, and State of New Jersey, United States of
America, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
The object of this invention is to facilitate the deposition by electricity of a
metallic coating upon the surface of a large object. By this invention, an object
like the hull of a large iron ship, which cannot be immersed conveniently in a bath of
electro-plating solution, is provided with an integral coating by depositing the
inetal upon definite portions or sections of the surface successively, and causing the
deposits to overlap upon one another.
I have found that sections thus overlapped are perfectly united at their junction; 80
that the entire coating upon the object, whatever the extent of its surface, becomes
an unbrken metallic sheet.
The invention consists partly in the methods I have devised for depositing an
integral coating upon a large surface in sections, partly in the means for applying
a bath of plating solution to a definite portion or section of the surface, and partly
in the means for retaining the solution within the bath holder in contact with the
under surface of an object, as the bottom of a ship.
In the drawing, Fig. 1 is a diagram of a ship's hull with a series of bath holders
applied thereto; Fig. 2 shows the inner side of one of the bath holders;
Fig. 3 represents the packing at one corner of the bath holder; Fig. 4 is a section
of one edge of the bath holder, taken on line in Fig. 2, with a portion of the
vessel's skin. Fig. 5 is a section on line y y in Fig. 2, through one of the inlet
thimbles. Fig. 2 is drawn upon a much larger scale than Fig. 1, and the details in
Figs. 3, 4 and 5, upon a still larger scale. Fig. 6 is a midship section of a vessel
in a diy dock, with several bath holders applied to the hull. Fig. 7 shows a
portion of the vessel amidship, in side elevation, supported in a dry dock, with
several bath holders secured upon the hull.
Fig. 8 is a plan and Fig. 9 an inside view of a bath holder provided with
electro magnets at the corners, and having the anode insulated therein. Fig. 94 is
an end view of the anode with one of the insulators; Fig. 10 is an outside view of
a bath holder similar to that shown in Figs. 8 and 9, but having the magnets
combined with an abutment frame, the frame and magnets being omitted at the
left side of the figure; Fig. 11 is an end view of the same taken at the right

page_text: hand end; Fig. 12 is an edge view of an auxiliary abutment frame provided with
magnets at the corners and having the bath holder attached to it transversely at
the middle; Fig. 13 is an elevation of the abutment frame detached from the
other parts; Figs. 14 and 15 are an end view and plan of bath bolder having an
abutment frame provided with pulley arms at the corners; and Fig. 16 is an
elevation of the abutment frame and pulley arms. Fig. 17 shows the stern of a
vessel in dry dock with a bath holder applied thereto, the bath holder being shown
in section on line in Fig. 19. Fig. 18 is a side elevation of the same parts with
a portion of the bath holder broken away. Fig. 19 is a plan of the bath holder
with a horizontal section of the stern of the vessel on line 2 in Fig. 17.
Fig. 20 is a plan of one of the screws for pressing the packing against the skin
of the vessel; Fig. 21 is a cross section of a keel bath holder, adjacent to one
end, with the keel in section within the bath holder. Fig. 22 represents one corner
of a bath holder with a portion of the skin of a vessel and the anode, in section on
line w to in Fig. 23, which shows the lower corner of the bath holder upon its inner
side; Fig. 24 is a plan view of one of the elbows or junction pieces for the corner
of the packing; Fig. 25 is an elevation of one of the extension shores and spring
shoe in section at the center line where hatched; Fig. 26 is a transverse section of
a bath holder made of sheet metal; Fig. 27 is a plan of a bath holder formed
chiefly of wooden strips; Fig. 28 is an end elevation, and Fig. 29 shows the outside
of the bath holder at one end. In Fig. 1, H is the hull of the vessel and B the
sectional bath holders, eleven of which are shown in a series arranged alongside of
the vessel. D indicates an electric generator or dynamo, the negative conductor N'
of which is connected to the bow of the vessel, and the positive conductor N is
connected in multiple are with a series of bath holders.
The vessel is shown supported upon blocks a, as would be requisite in a dry
dock; but the bath holders may be applied to the vessel before it is launched if
desired.
To form a bath holder adapted to retain the plating solution in contact with a
definite portion of the surface i provide a frame having a waterproof lining, and
provide the margin of the frame with a packing adapted to hold the lining at a
suitable distance from the skin of the vessel. The packing is adapted to make
a tight joint with the skir of the vessel, and an anode is inserted within the
bath holder to convey the electric current to the solution.
Fig. 2 shows the inner side of a rectangular bath holder, b designates the lining
of the bath holder, c the packing, and d are thimbles by which the plating
solution may be introduced or withdrawn at pleasure. A corner of the frame e of
the bath holder is indicated in Fig. 4 with the lining stretched flat upon the
frame. The packing e shown in Fig. 4 is constructed entirely separate from the
lining, being made as a rectangular strip of india rubber or other yielding fabric,
with longitudinal corrugations c¹ upon its opposite edges, and a rectangular groove f
formed upon its outer side. The packing is set within the margin of the frame to
leave a seat for securing clamps to hold the packing in place. The clamps are
shown in the form of clips g which are fitted to the groove f and are secured to the
frame outside the packing by screws or bolts h. Such a packing may be bent at
the corneis after notching the same, as indicated at j in Fig. 3, and its ends united
by a half lapped joint with plates rivetted over the same, as at k in Fig. 2.
When such a frame is pressed toward the skin of the vessel (indicated by the
letter S in Fig. 4) the edges of the packing yield readily owing to their corrugated
structure, and thus form a tight joint between the bath holder and the surface to
which it is applied. The lining b of the bath holder may be made of india rubber
or any waterproof fabric, which owing to the construction may be used in perfectly
flat sheets.
By holding the packing upon the margin of the bath holder by suitable clamps
the perforation of the packing and the lining where in contact with the saine, is
avoided, and the liability to leakage from such perforations is prevented.
Where the thimbles d are inserted through the lining, the frame, whatever it

page_text: construction in other respects, is provided with a suitable plate or support indicated
at in Fig. 5, upon which the packing may be clamped between the head d' of the
thimble and a nut d' outside of the plate.
The bath holder shown in Fig. 2 with a packing around its entire margin is
adapted for application to a sloping or nearly level surface, but where the bath
holder is applied to a nearly vertical surface, the packing may be omitted at its
upper edge, and blocks or stays inserted in place of the same to hold the upper
edge of the bath holder at a suitable distance from the surface to which it is
applied. Such a construction is shown in Figs. 22 and 23, in which the frame is
formed of longitudinal bars e and transverse bars e¹. Such frame may have inter-
mediate bars to form a grating between the marginal bars e and support the lining b
against the internal pressure, as in Fig. 10. The margin of the bath holder is
shown in the construction Figs. 22 and 23 provided with two wooden strips n n¹,
with the lining wrapped around the inner strip n and the outer strip n¹ clamped
closely by the side of the same.
The adjacent edges of the two strips are grooved to receive a tubular packing c³,
which is secured in place by an interior gib and screws m extended through the
strip n. Such construction requires the fitting of the lining upon its corners and
four edges to the strips, but admits the use of a rubber hose as a convenient form
of flexible packing, with special elbows to join the hose at the corners (see
Fig. 24).
Such hose can be obtained when required in the open market, whereas, the
packing e shown in Fig. 4 requires to be specially made for the purpose.
The tubular packing c is shown at the margin of the bath holder in Fig. 8, and
as such packing is applied to only three sides of the same, means are required to
hold the top edge at an equal distance from the skin S of the vessel, to provide
suitable space for the anode. In Fig. 10 some of the transverse frame bars e¹ are
shown projected beyond one edge of the frame, to receive insulating blocks as
shown at t in Fig. 8, which thus serve to hold the top of the bath holder parallel
with the skin S of the hull. Any equivalent for such blocks may be used where
the packing is omitted at one edge of the bath holder. The view of the bath
holder in Fig. 10 exhibits merely the outer side of the bath holder with the
magnets attached to the frame, the other attachments of the bath holder being
shown in Figs. 8 and 9 in connection with the skin of the vessel.
Au anode b', as a sheet of copper, is shown in Figs. 8, 9 and 22, provided with
insulators consisting ench in a strip of wood o split from one end nearly to the
other, and having the divided parts pressed together, to clamp the anode, by means
of a screw of Fig. 94. The wood is made of much greater thickness upon one side of
the anode, to hold it at a suitable distance, as two or three inches, from the surface
to be plated, the wood upon the opposite side of the anode affording merely a space
for the circulation of the plating fluid.
A portion of the wooden insulators are provided with handles p; and binding
posts p², connected with the positive conductor N and with the abode, are shown
attached to other of the insulators.
Where the bath holder is formed, as in Fig. 2, with its entire margin enclosed,
the anode would be enclosed within the bath holder, and the positive conductor
extended through some portion of the bath holder, by any well known means, into
contact with the same. In Fig. 8, the bath holder illustrated in Fig. 9, is shown
applied to a portion of the vessel's skin S, having a convex surface. It is obvious
that a straight frame, if made of steel or other highly elastic material, would be
pressed firmly against such convex surface over the greater part of its length, if
bent by pressure until parallel with the surface. The frame in Figs. 8 and 9 is
shown provided at the corners with electro magnets M having screw threads fitted
to the lugs M' upon the frame.
Such magnets when made of proper proportions are capable of such adhesion to
the skin of an iron vessel as to hold the frame in the position shown, and in any
suitable location. The magnets are provided with shanks m³ by which they may

page_text: be screwed through the lugs M, and the bath holder may thus be adjusted at the
ends into the desired contact with the surface to which it is applied.
Such a construction, while adapted for a smooth surface of sufficient convexity,
furnishes no means for adjusting the packing independently at different points
upon the margin of the frame, so as to stop a leak when a defective joint is
formed.
Such means of adjusting the packing is provided in an abutment, which may be
attached to the frame as in Figs. 12 to 15, or may be separate from the same, upon
any fixed object, as in the dry dock illustrated in the Figs. 6 and 17. In Figs. 12
to 15, the abutment is an auxiliary frame A, attached to the bath holder across its
middle line by bolts q, and provided with numerous set screws & adapted to press
upon the margin of the bath holder at frequent intervals, to adjust the packing
independently at such points. In Figs. 11 to 13, the abutment A is provided with
magnets M for securing it to the skin of the vessel, the magnets being adjustable
to bring the middle of the frame into close contact with the surface, and the
remainder of the frame being pressed into the desired contact by means of the
screws 8. The pole pieces M of the magnets in Figs. 10 and 11, are shown attached
to the opposite ends of bars P which are connected by the tie bars P¹. The pole
pieces are freely movable through lugs M' upon the bath holder, and the ends of
the bath holder are adjusted by set screws inserted through the magnet bars P.
With this construction the pole pieces with their bars P and P' may be fixed
rigidly to the skin of the vessel when the latter is of convex form, and the entire
bath holder then pressed firmly against the surface by the set screws s at the
opposite ends. The bath holder formed with a grating of elastic metallic bars is
best adapted for use upon a highly convex surface where no abutment is required,
but where an abutment is used a very cheap and flexible form of frame for the bath
holder is made by attaching two metallic bars to a series of wooden strips, which
are free to bend independently of one another. Such construction is shown in
Figs. 27 to 29, the two bars e being connected at their ends by bars e¹ and secured
to the series of wooden strips or boards e. The boards are shown provided with
the waterproof lining band packing c like that in Fig. 4. A highly flexible frame
adapted to use with an abutment, or with analogous means for tightening the
packing at various points, may be made by securing a thin plate of iron p² to the
bars e e, which construction is indicated in longitudinal section in Fig. 26.
In Figs. 14 to 16, a bath holder is shown attached to an abutment A having
braces or arms E projected from its outer surface with pulleys o' in their ends to
receive a rope F. The abutment frame is formed with an oblique bar for the
bolts 9, so as to bend the bath holder readily to fit a warped surface, as indicated
in Figures 14 and 15. With such a construction, the bath holder may be pressed
against any convex portion of a vessel by a rope tangential to the surface of the
hull ; as indicated in Fig. 6, where a mid section of a hull is shown resting upon
the keel blocks a upon the floor I of a dry dock. A rope F is shown attached to
the end of a keel block and extended over the arms E upon a bath holder B
upon the right hand side of the hull. A rope tackle F¹ is shown, to tighten the
rope tangential to the hull; and other equivalent means, as a screw bolt, may be
used for such purpose. Two or more wire ropes may be by such means extended
over the outer side of a bath holder and operated to hold it with great firmness in
the desired position. A tank K of electro plating solution is shown supported a
little above the level of the bath holder B, and the upper part of the bath holder
is connected therewith by a pipe. An outlet pipe having a cock v is connected
with the lower part of the bath holder and arranged to discharge into a
receptacle v. By properly regulating the cock, a current of plating solution may
be conducted continuously through the bath holder; which greatly hastens the
electro deposition upon the surface to be plated. On the right hand side of the
keel a bath holder B is shown formed of an angular shape, its lower member being
adapted to fit one side of the keel, and its upper member to fit the bottom of the
vessel adjacent thereto.

page_text: upon
The lower member of the bath holder is clamped firmly to the hull by means of
bolts passed through the edge of the bath holder and through strips r¹ the
opposite side of the keel, and the upper member of the bath holder is shown
pressed to the bottom of the hull by a rope, like the other bath holder upon the
same side of the hull. Upon the bottom of the vessel at the left side of the keel,
is shown a bath holder B³ pressed toward the surface by a rope tackle like the
bath holder B in the same figure, and the upper part of the bath holder is shown
connected with a receptacle by an outlet pipe u. A pump wis arranged to draw
the plating solution from the receptacle, and is connected with the lower edge of
the bath holder B2 by a pipe u', so as to force the solution continually through the
bath holder into the receptacle.
By the use of the pump thus connected, or the tank K sustained above the level
of the bath holder and discharging through the same by a regulated flow, the
solution within the bath holder is held under a sufficient pressure to force it into
continuous contact with the surface of the hull. The bottom of an object may
thus be kept constantly bathed by the solution so as to receive the metallic deposit
therefrom in the desired manner. Upon the left side of the hull a hath holder B
is shown secured to the skin of the vessel by the electro magnets M, and a bath
holder B is shown beneath the same with expansion shores L inserted between the
bath holders and the steps 12 of the dry dock. The shores, as illustrated in
Fig. 25, are provided with shoe 2 and a screw shank and nut L', which when
turned extend or lengthen the shores and thus operate to press the bath holder or
an abutment frame toward the hull as desired. In Figs. 22 and 27, concave
sockets L are shown upon the outer side of the bath holder near the end, and such
sockets are adapted to receive the end of the shores L and to thus hold the shores
in a desired relation to the bath holder. A spring L³ is shown inserted between a
collar upou the shank and the shoe, and the extension of the shore thus operates
to compress the spring and thereafter maintains an elastic pressure against the bath
holder to which the shore is applied.
In Fig. 6, the hull H is shown supported within the dry dock by the usual
shores H, but, as it is not held absolutely in a fixed position, and its shape is liable
to vary by expansion with changes of temperature, I prefer to provide such com-
pensating springs for maintaining the pressure upon the bath holder when it is
attached to the hull by tackle or by expansion shores.
A spring L³ is shown applied to the rope F which holds the bath holder B upon
the right hand side of the hull H in Fig. 6, and such spring is stretched in a corre-
sponding manner when the rope is tightened by the tackle F. The spring there-
after operates to maintain an elastic tension upon the rope and to thus hold the
bath holder firmly in position under any variation in its adjustinent.
Fig. 7 shows an abutment frame used to press a bath holder adjustably against a
concave surface, as illustrated in Fig. 27. In this construction, the auxiliary frame
is attached loosely to the ends of the bath holder by dowel pins Q, and the set
screws operate to press the middle of the bath holder inwardly and to hold the
packing tightly against the concave surface at all the points required.
The bath holders so far described have been adapted by their flexible character,
to conform to a surface of tolerably uniform curve, as upon the bottom of the vessel
and the greater part of its sides; but where the surface is irregular it is more
convenient to build a sectional bath holder upward from the keel upon one or both
sides of the vessel, and thus apply the plating solution to the entire irregular surface
at once.
In thus operating, the keel, if desired, may be first plated by the means shown in
Fig. 21, where e and el represent the longitudinal and transverse bars forming the
fraine of the bath bolder, upon which is carried the lining_b. The packing is
designated by the letter c between the lining and the keel K¹ and the anode b¹ is
shown within the lining connected with the positive conductor N, the keel being
connected with the negative conductor N¹.
Clamping arins &² are shown embracing the frame of the bath holder, and extended

page_text: below the same to receive a set screw in their ends, and a tie-bolt adjacent to
the bottom of the bath holder. Such clamps would be applied to the ends of the
bath holder, at which points only the packing c would be required, and the bolt k*
may be regulated to tighten the joint at the bottom edge of the keel, while the set
screw ³ acts in opposition to the bolt to tighten the ends of the packing upon the
upper part of the keel. A wedge is shown fitted to the lower ends of the jaws
and supported upon a rigid seat 1 by which the packing immediately beneath the
keel may be held in close contact with the same. With such construction the
packing e confines the liquid at the extreme ends of the bath holder and is pressed
firmly against the metallic surface by the means described. Figs. 17 to 19 show
the stern of a vessel with the stern bearing and the rudder post wholly enclosed in
a bath holder built up from the floor of a dry dock.
Fig. 18 shows a portion of the wall of the bath holder broken away adjacent to
the stern post of the hull, and Fig. 17 shows a cross section of the bath bolder on
line in Fig. 19, which is a horizontal section on line ¹¹ in Fig. 17. I is the
floor upon which the weight of the vessel would be sustained by blocks a at suitable
points forward of the stein; leaving room for a platform 1 beneath the keel adjacent
to the stern, upon which the sectional bath holder is built.
A stopper 2 is shown inserted between the platform and the keel where the
packing 3 is applied at the forward edge of the bath holder, and such stopper is
made water tight against the platform and the keel. The bath holder is shown of
triangular form in plan with a post 4 at its apex, in the rear of the rudder post, and
sloping posts 6 are extended from the platform up toward the sides of the vessel at
the forward end of the bath holder and intermediate to the ends. Beams or
stringers 7 are stretched between the posts and faced internally with a boarding 8,
and the lining of the bath holder, which is omitted from Figs. 17 to 19 on account
of the smallness of the scale, is made water tight over the inner surface of the
boarding and the platform 1 within the same. The wall of the bath holder is
shown in Fig. 19 extended in a straight line from the rear post 4 to the first pair of
sloping posts 6, and is then bent at a slight angle to the second pair of sloping posts;
where gibs 9 are applied to the lining of the bath holder to press it against the side
of the hull. As an irregular space exists between the sloping posts and the wall of
the vessel, the lining of the bath holder is extended across such space and supported
by boards or plates 11, Fig. 20, which are held in place by knees or angle braces 12
affixed to the outside of the bath holder.
The braces are provided at the ends with set screws 13 adapted to press at
intervals upon a gib 9 conforming with the curvature of the hull, and beneath which
the lining is inserted with a yielding packing 14 adapted to compensate for
irregularity in the surface of the hull.
The brackets 12 are shown in dotted lines in Fig. 17, but the set screws are
omitted on account of the smallness of the scale. The stopper 2 furnishes a water
tight junction at the forward end of the bath holder between the platform 1 and
keel K', and the pressing of the lining b against the sides of such stopper and
against the platform, as indicated by the dotted lines 15 in Fig. 17, closes the bath
holder completely at the forward end. The bath holder would be extended up to
or above the water line upon the hull so as to plate the required portion of the
surface.
The surfaces to be plated would be suitably cleaned, and any apertures to the
side of the vessel and the bearing for the propeller shaft would be blocked up and
rendered water tight and the bath holder could then be filled with the plating
solution and an anode 6¹ introduced therein as shown in Figs. 17 and 20. The anode
being connected with the positive conductor and the hull with the negative con-
ductor, the copper would be deposited upon all the portions of the surface within
the bath holder, including the stern bearing, the keel, the rudder post, &c.
Where the keel has been previously plated, the bath holder may be constructed
without the platform by bring the boarding 8 close to the bottom edge of the
keel, and clamping the lining of the bath holder to the opposite sides of the keel

page_text: by suitable clamps, thus forming a water tight bottom for the bath holder; within
which the plating would be deposited continuous with the plating already upon the
keel. The stem of the vessel may be plated by the same means as the keel, by the
bath holder shown in Fig. 21, but the curvature is cominouly so gradual upon
the bow of an iron vessel, that the bath holders with flexible frames may be applied
to plate the same without difficulty. Where it is desired, the stem of the vessel
may be enclosed in a bath holder like that illustrated in Figs. 17 to 19, and both
sides of the bow plated at the same time as far back from the stem as is desired.
Two sets of sloping posts 6 are shown in Figs. 18 and 19 to illustrate a means for
enclosing an entirely transverse section of a vessel, at any point between the stem
and stern, as it is obvious that the end of the bath holder may be closed in like
manner at both sets of posts, and a vertical strip of surface thus be enclosed and
plated simultaneously upon the side of the hull. An alternate series of such strips
may be readily plated and similar bath holders applied to the intervening strips to
deposit the copper upon the intervening portions of the surface. By overlapping
such deposits upon the portions of surface previously plated, the coating is made
integral throughout.
In Figs. 1 and 7, dotted lines 17 are arranged to represent rectangular sections
of plating overlapped upon one another to form an integral coating.
Several bath holders are shown in Fig. 7 with their weight suspended by ropes 19
from pulley blocks 18. One or more bath holders may thus be adjusted upon the
surface of a vessel and the pressure then applied to clamp the packing thereto, the
means of support, as the rope 19, being retained, while the bath is in use, to
prevent the falling of the bath holder if the clamping devices become relaxed as
would occur if supporting magnets were used and the electric current accidentally
cut off.
The bath holders are shown in Fig. 7 clamped or pressed toward the side of the
vessel by the various devices shown in Fig. 6; excepting the shores L. At the
left side of Fig. 7, two bath holders B³, clamped to the surface by magnets, are
shown adjusted to form a deposit overlapping upon those previously made.
To thus adjust the bath holders, the surface of the vessel after cleaning may be
marked off, by chalk lines, into spaces one or two inches less in dimensions than the
internal size of the bath holder, and the bath holder when one end is set to such lines
would overlap at the opposite end upon any plating previously deposited. Where
a series of such sections is marked upon the surface of the vessel, a series of bath
holders may be applied to the alternate sections as shown in Fig. 1, and after such
sections are plated by the bath holders may be shifted each to the adjoining section,
which, owing to the previous measurements of the sections, would permit the
succeeding deposits to be overlapped at both ends upon those already formed.
Where bath holders of rectangular form are applied to a warped surface the
edges of the deposit would not form level lines, and as a bath holder with an open
top is preferably adjusted in a level position, the oblique edge of the previous
deposit may be painted over with a non-conducting paint within a short distance of
its edge, so that the succeeding deposit shall be united at such short distance of
its edge alone. Such a patch of paint 20 is indicated in Fig. 7, beneath the bath
holder B³ the sloping dotted lines 21 immediately below such patch indicating
the position which the bath holder would necessarily take if applied to a warped
surface. The dotted lines 22 in the bath holder above the wedge of paint show
the interior dimensions of the bath holder; which would be made of some standard
size in feet or inches to facilitate the laying out of the surface to adjust the bath
holder. The surface of the vessel may be cleaned to receive the plating solution
by any suitable means, and it is obvious that a portion of the surface may be plated
while another portion is undergoing the cleaning operation, and the places thus
plated and cleaned may be laid out with reference to uniting the sections by bath
holders of standard dimensions. A bath holder four feet by ten would cover forty
square feet of surface, and may be made so light by the methods of construction
herein described, as to be handled and adjusted with great facility.

page_text: From the above description it will be seen that the invention consists essentially
in depositing a series of definite overlapping sections upon the surface, it being
impossible to plate an indefinite surface with a bath holder of given area.
A bath holder of given area may however be adapted to plate a definite surface
less than its own area by coating a portion of the surface with a non-conducting
medium as just described. This invention is readily distinguished from any method
of coating the surface by washing or painting the same, as it involves the application
of the plating solution to a definite section of the surface, and the retaining of such
solution in contact with the surface for a definite length of time to produce an electro-
metallic deposit of the desired thickness.
The art of electro plating is already well understood, so
that the proper
proportions of the anode and the current to produce a given deposit may be readily
determined, and this method therefore furnishes a means of securing a coating of
definite thickness upon the hull of the vessel.
The copper can be deposited most rapidly from a solution of copper sulphate, but
such solution can not be first applied to an iron surface, as the iron decomposes the
same, and a cyanide solution may therefore be applied to the bath holders by any
suitable means when first secured in position, and when the iron surface is
protected by the copper such solution may be withdrawn and replaced by a solution
of copper sulphate.
The bath holder may also be used as a means of cleaning the surface of the
vessel after the ordinary paint is removed; by first applying the bath holder with
a suitable pickle of sulphuric acid, then drawing off such pickle from the bath, and
then flooding the bath holder and the iron surface with clean water and
immediately filling the bath bolder with the cyanide solution to electro plate the
same before it has become oxydized by exposure to the air. By the use of suitable
inlets and outlets, like the thimbles d' shown in Figs. 2 and 3, such fluids may be
introduced at one edge of the bath holder and removed from the opposite edge of
the same so as to wash the entire surface of the iron to which the bath is applied.
The deposition from a cyanide solution is greatly promoted by heating the solution,
and where it is not convenient to introduce any heating appliances (as a steam pipe
within the bath) a heated solution may be pumped or flowed continuously through
the bath holder from a receptacle in which it is kept at the proper temperature.
The means for thus feeding the bath holders is shown in Fig. 6, and other means
may be employed where required.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. The method of forming an integral metallic coating upon a large surface,
which consists in electro-depositing a series of definite overlapping metallic sections
upon such surface, substantially as herein set forth.
2. The method of making an integral metallic coating upon a large surface,
which consists in first forming a metallic electro-deposit upon a series of alternate
sections, and second, forming a similar metallic deposit upon the intermediate
sections and overlapping upon the previously formed deposits, as set forth.
3. The method of electio plating a portion of the surface upon an object, which
consists in confining a fluid bath of plating solution to such portion of the surface,
passing an electric current through the bath to such surface and simultaneously
passing a moving current of the plating solution through the bath, as herein set
forth.
4. The method of electro plating a portion of the under surface of an object, as
the bottom of an iron vessel, which consists in confining a bath of plating solution
to such under surface, passing an electric current through the bath to such surface,
and maintaining the plating solution under fluid pressure in contact with such surface,
as herein set forth.
5. A sectional bath holder having a packing at the margin, and means for

page_text: compressing the packing independently at different portions of the margin, as set
forth.
6. A sectional bath holder having a packing at the margin, in combination with
an abutment, and means connected with the abutment for conforming the packing
to a given object, as set forth.
7. A sectional bath holder comprising a frame, a flat lining stretched over the
same, and a yielding packing applied to the margin of the lining, as shown and
described with reference to Fig. 4.
8.-A sectional bath holder having a packing at the margin, in combination
with an abutment, means connected with the abutment for conforming the packing
to a given object, and magnets to hold the abutment in a fixed position, substantially
as shown and described with reference to Figs. 11 and 12.
9. The combination, with a sectional bath holder, of means for pressing the
same elastically toward the side of the vessel, as by the spring L³, as shown and
described with reference to Figs. 6 and 25.
10. The combination, with the keel or stem of a vessel, of a sectional bath
holder having parts jointed together and pressed toward one another upon opposite
sides of the vessel, as shown and described with reference to Fig. 21.
Dated this 30th day of May 1893.
FELL & WILDING,
Agents for the Applicant.