IMPROVEMENTS IN The MODE OF AND ARRANGEMENTS FOR ATTACHING SHEET ZINC OR OTHER SUITABLE ELECTRO-POSITIVE METAL OR ALLOY AS A SHEATHING TO THE HULLS OF IRON OR STEEL SHIPS AND STEAM VESSELS, AND TO SUBMERGED OR PARTIALLY SUB- MERGED FIXED OR FLOATING IRON OR STEEL STRUCTURES, FOR PREVENTING CORROSION AND FOULING, APPLICABLE ALSO FOR ATTACHING TOGETHER OTHER SHEET METALS OR PARTS FOR OTHER USES
Year: 1879

page_text: LETTERS PATENT to Charles Frederic Henwood, of 28, Budge Row, in the City
of London, Naval Architect, for the Invention of "IMPROVEMENTS IN The
MODE OF AND ARRANGEMENTS FOR ATTACHING SHEET ZINC OR OTHER SUITABLE
ELECTRO-POSITIVE METAL OR ALLOY AS A SHEATHING TO THE HULLS OF IRON
OR STEEL SHIPS AND STEAM VESSELS, AND TO SUBMERGED OR PARTIALLY SUB-
MERGED FIXED OR FLOATING IRON OR STEEL STRUCTURES, FOR PREVENTING
CORROSION AND FOULING, APPLICABLE ALSO FOR ATTACHING TOGETHER OTHER
SHEET METALS OR PARTS FOR OTHER USES."
PROVISIONAL SPECIFICATION left by the said Charles Frederic Henwood
at the Office of the Commissioners of Patents on the 27th May 1879.
CHARLES FREDERIC HENWOOD, of 28, Budge Row, in the City of London, Naval
Architect. "IMPROVEMENTS IN THE MODE OF AND ARRANGEMENTS FOR ATTACHING
SHEET ZINC OR OTHER SUITABLE ELECTRO-POSITIVE METAL OR ALLOY AS A
SHEATHING TO THE HULLS OF IRON OR STEEL SHIPS AND STEAM VESSELS, AND
TO SUBMERGED OR PARTIALLY SUBMERGED FIXED OR FLOATING IRON OR STEEL
STRUCTURES, FOR PREVENTING CORROSION AND FOULING, APPLICABLE ALSO FOR
ATTACHING TOGETHER OTHER SHEET METALS OR PARTS FOR OTHER USES."
This Invention has for object the attainment of a simple and practical mode
and arrangement for the attachment of sheet zinc or other suitable electro positive
metal or alloy as a sheathing or covering for protecting the hulls of iron or steel
ships and steam vessels, or other submerged or partially submerged fixed or floating
iron or steel structures from corrosion, and which will also prevent the fouling of
the same without requiring a special construction to enable it to be used, and
without the employment of any mode or means which would weaken or deteriorate
the hull or structure by its use, and which improved mode and arrangement
may also be employed for attaching together other sheet metals or metal parts,
and consists in obtaining a metallic connexion with the iron or steel hull or
structure by the aid of heat, as in ordinary soldering, or a jet of gas flame, such as
the "aëro-hydrogen" or "aero- gas blow pipe" and the aid of a suitable solder
or alloy, or by the employment of what is known as autogenous soldering, or

page_text: attaching the metal by melting or "burning" a portion or portions of the same,
whereby I am enabled to secure the sheet metal, zinc, or other suitable alloy to the
iron, steel, or other metal in places, strips, rings, spots, patches, or rows, in place of
having to solder or attach it over the entire surface, as has been heretofore pro-
posed, whereby in the case of sheathing iron or steel vessels or structures I am able
to secure the access of the sea water between the surfaces, and thus to increaso
the extent of galvanic action.
Many methods for attaining this end have been devised and patented, but all of
them have been more or less open to objection; in the case of requiring special con-
struction for its use may be instanced the plan shewn in the Patent of Mr. T. B.
Daft, No. 2331, of 1863, which necessitated special means for retaining the com-
pressed teak (to which the sheet zinc was to be attached by nails) between the edges
of the plates, and although obtaining a most perfect and firm attachment of the
sheet zinc round its edges, did not provide a simple and practical means of securing
the "bunt" or middle portion of the zinc sheet to the iron except by the employ-
ment of holes drilled in the plates of the hull of the ship, into which holes screws,
nails, or plugs were to be inserted to hold the sheet zinc; and in the case of
weakening the ship may be taken the more objectionable plan patented by Mr. N.
Barnaby, in Patent No. 2326, of 1868, where it was proposed to drill holes into the
rivets which held together the plates forming the hull of the ship, into which holes
the screws to be employed to attach the sheet zinc to the hull were to be inserted,
both of which plans at once shewed their disadvantage, and in consequence
have not been aodpted; but by my improved arrangement and mode of appli-
cation however, I am enabled to attach the sheet zinc in the "bunt," or body, or
middle of the sheet as well as at the edges in a firm and practical manner without
requiring any special mode of construction, or the drilling of holes in the plates of
the hull, or any other objectionable, complicated, or expensive method or mode of
operation, and thus attain the desired end.
In carrying out my Invention I cause the sheets of zinc or other suitable electro
positive metal or alloy to adhere to the surface to which they are applied by means
of solder or a suitable alloy applied in detached patches, rows, spots, strips, rings, or
other equivalent mode; and to obtain a proper adhesion of the zinc and iron or
steel, as herein before described, I also by preference cause the solder or suitable
alloy used for attaching them to take a peculiar form, or be shaped into what may
be termed "hollow" or "flanged washers," or other suitable form, for the position
in which they are to be used, either by casting or moulding them into shape by the
aid of a press and dies or other suitable means, in order that by that form and the
use of the flame jet I may be enabled to secure more perfect action of the heat
on the plates or parts to which the sheet zinc is to be attached on the solder or
alloy which attaches them and the zinc sheet itself, which is attached by the process
during its operation; and the mode I adopt by preference for applying the heat is
that of a jet of gas or suitable vapour flame, such as, for examplo, that available by
the apparatus invented by Count de Richemont, and patented by M. Delbruck in
Patent No. 8624, of 1840, or any other equivalent method or arrangement suitable
for the purpose.
I am aware that soldering metal sheathing to iron ships has been proposed before,
and that in the year 1862 a Provisional Protection, No. 1503, was obtained by
Joseph Needhain for the use of this plan, but he caused the "suitable metallic
sheathing" to adhere by "soldering it over its entire surface," and by so doing
the exclusion of the sea water from access to the inner surfaces of the "suitable
metallic sheathing" and the exterior surface of the iron hull to which it was to be
attached would result, and the amount of galvanic action which is desirable to be
obtained for the prevention of fouling, although not so necessary for the preservation
of the iron, would thereby be prevented to a great extent. By iny improved method
it will be seen that I avoid this difficulty and at the same time obtain an efficient
means of attachment, and thus combine the advantage of attaining the two objects
in one operation.

page_text: Having cut the zinc sheet to fit the dimensions and shape of the place or part
it is to occupy, I punch around the edges of same a row or rows of holes of the
diameter and the distance apart or pitch desired or required, and also such other holes
as may be decided in the "bunt" or middle portions of the sheet and then, having
placed the sheet on or against the place or part it is to occupy, I with a piece of
tube, cork, or other suitable material dipped in white paint, chalk, or whitening and
water, or other convenient and suitable colouring or marking material, mark through
each hole on the surface or part of the iron or steel the position of the same, so as
to shew what part of the iron or steel each flanged solder washer or hollow rivet,
or other attaching portion will come in contact with, and having completed the
marking, the sheet is taken down, and those parts shewn by the marks on the iron
or steel (having the surface clean from paint, dirt, grease, or rust) are then further
cleaned with spirits of salts, and a suitable soldering fluid applied capable of causing
or aiding the adhesion of the solder or alloy to the iron or steel. Whilst this is
being done, another person may be employed in cleaning, where needed, and
moistening the surface of the sheet zinc on the side which comes in contact with the
iron or steel with muriatic or other suitable acid round the surface at each hole, and
inserting in each holo a flanged solder washer or hollow rivet (previously dipped in
a suitable flux), so that the projection or part on the flange or head of the hollow
solder rivet shall be in the punched hole in the zinc sheet, and then, all the holes
being properly supplied with the solder or alloy, the zinc sheet is to be returned to
and kept firmly in its place and against the moistened iron or steel, the flange of
the washer or head of the hollow rivet or other attaching part being pressed against
or kept in contact with the moistened iron or steel, and then by causing the flame
jet to play into the hole of the flange or solder rivet or other attaching part, the iron
or steel becomes sufficiently heated, the solder or alloy melts and adheres to the
metal, the force of the flame jot at the same time causing the melted solder or alloy
to enter between the zinc sheet and the iron or steel and spread between them, and
a few sweeps of the flame jet over the exterior surface of the zinc sheet round each
hole or attaching part where the solder or alloy is used finishes the molting, and on
cooling leaves the sheet of zinc firmly attached to the iron or stoel. It will be found
an advantage if, on completing the soldering at each hole and before the alloy or
solder sets, the zinc sheet is pressed up to or against the iron or steel by means of a
hammer or other suitable or convenient means of securing the close contact of the
two metals, whereby a very complete job will be made.
I may sometimes modify the mode herein before described by attaching drops or
buttons, strips, rows, rings, or spots of the solder or alloy on the side of the zinc
sheet or other suitable electro-positive metal or alloy which is to come in contact
with and be attached to the iron, steel, or other metal to which it is to be applied,
and then having applied to each drop, button, strip, row, ring, or spot of the solder
or alloy some marking stuff, the same will, on being brought into contact with the
metal to which it is to be attached, transfer a portion thereof at once, shewing the
positions which the solder or alloy will require to have cleaned and prepared for
their attachment, and on this being done and the solder or alloy wiped, cleaned, and
washed with a suitable flux or soldering fluid as herein before described, the sheet
may be placed in position and sufficient heat may be applied to the outside of the
zinc or other metal or alloy to melt the solder, when the required attachment at
once takes place. It will be manifest that in certain cases in place of putting the
solder or alloy on the zinc or other metal sheathing, used as above described, it may
be attached to the iron, steel, or other metal plates or portions, and the heat applied
as above described, their positions being previously marked by the aid of a template
or its equivalent both on the metal to be attached and the metal to which the
attachment is to be made.
In certain cases, in place of punching holes at the edges of the sheet zinc or other
suitable electro-positive metal or alloy, I may form the solder or alloy attaching
portion so as to be applied to and secure the "butts" or end edges of the plates
O 5532. Wt. 20603.

page_text: either entirely along their length or only partially, as may be desired or preferred,
and the top and bottom edges of each sheet may be attached in a similar manner
by a similar or suitable arrangement of the solder or alloy attaching part.
At the top, bottom, and ends or termination of the strakes of sheathing I may
apply a thicker portion of zinc, galvanized iron, or other suitable material capable
of being readily attached by solder or alloy both to the iron or steel plates and the
sheathing, so formed as to act as a fender or guard to the ends, edges, or termination
of the sheathing, and prevent as far as possible any liability to hitching or hanging
on to the same of such things as might come in contact with the ends, edges, or
terminations, and cause the same to become detached or partially detached. This
thicker portion may be of any required or desired length, breadth, or thickness, or
suitable form, according to the circumstances of the case or the desire of those for
whom the work is executed.
When the autogenous soldering process is adopted suitable holes are punched in
the sheets where desired, the iron or steel to which the sheet or sheets are to be
attached is marked, cleaned, and fluxed, the sheet is then placed in the position it is
to occupy, and the flame jet applied.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Frederic Henwood in the Great Seal Patent Office on tho
27th November 1879.
CHARLES FREDERIC HENWOOD, of 28, Budge Row, in the City of London, Naval
Architect. "IMPROVEMENTS IN THE MODE OF AND ARRANGEMENTS FOR ATTACHING
SHEET ZINC OR OTHER SUITABLE ELECTRO-POSITIVE METAL OR ALLOY AS A
SHEATHING TO THE HULLS OF IRON OR STEEL SHIPS AND STEAM VESSELS, AND
TO SUBMERGED OR PARTIALLY SUBMERGED FIXED OR FLOATING IRON OR STEEL
STRUCTURES, FOR PREVENTING CORROSION AND FOULING, APPLICABLE ALSO FOR
ATTACHING TOGETHER OTHER SHEET METALS FOR OTHER USES."
This Invention has for its object the attainment of a simple and practical modo
and arrangements for the attachment of sheet zinc or other suitable electro positive
metal or alloy as a sheathing or covering for protecting the hull of iron or steel
ships and steam vessels or other submerged or partially submerged fixed or floating
iron or steel structures from corrosion, and which will also prevent the fouling of
the same without requiring a special construction to enable it to be used, and
without the employment of any mode or means which would weaken or deteriorate the
hull or structure by its use, and which improved inode and arrangement may also be
employed for attaching together sheet metals or metal parts, and consists in obtaining
a metallic connexion of the sheet zinc or other suitable electro positive alloy with
the iron or steel hull or structure by the aid of heat, as in ordinary soldering, or a
jet of gas flame such as the "aëro hydrogen" or "aëro gas blow-pipe " and the aid
of a suitable solder or alloy, or by the employment of what is known as "auto-
genous soldering," or attaching the metal by melting by "burning "a portion of the
same, whereby I am enabled to secure the sheet metal, zinc, or other suitable electro
positive alloy to the iron, steel, or other metal in places, strips, rings, spots, patches,
or rows in place of having to solder or attach it over the entire surface as has
been hitherto proposed, whereby in the case of sheathing iron or steel vessels or
structures I am able to secure the access of the sea water between the surfaces, and
thus to increase or regulate the extent of galvanic action.
Many methods for attaining this end have been devised and patented, but all of
them have been more or less open to objection. In the case of requiring special
construction for its use may be instanced the plan shewn in the Patent of Mr. T.
B. Daft, No. 2331, of 1863, which necessitated special means for retaining the
compressed teak (to which the sheet zinc was to be attached by nails) between the
edges of the plates, and although obtaining a most perfect and firm attachment of
the sheet zinc round its edges did not provide a simple and practical means of
securing the "bunt" or middle portion of the zinc sheet to the iron except by the
employment of holes drilled in the plates of the hull of the ship, into which holes
screws, nails, or plugs were to be inserted to hold the sheet zinc, and in the case of
weakening the ship, may be taken the more objectionable plan patented by Mr. N.
Barnaby in Patent No. 2326, of 1868, were it was seriously proposed to drill holes
into the rivets which hold together the plates forming the hull of the ship, into
which holes the screws to be employed to attach the sheet zinc to the hull were
to be inserted, both of which plans at once shewed their practical disadvantages,
and in consequence have not been adapted; but by my improved arrangement and
mode of application however I am enabled to attach the sheet zinc in the "bunt"
or body or middle of the sheet as well as at the edges in a firm and practical manner
without requiring any special mode of construction or the drilling of holes in the
plates of the bull or any other objectionable complicated or expensive method or
mode of operation and thus attain the desired end.
In carrying out my Invention I cause the sheets of zinc or other suitable electro-
positive metal or alloy to adhere to the surface to which they are to be applied by
ineans of solder or a suitable alloy applied in detached patches, rows, spots strips,

page_text: rings, or other equivalent mode, and to obtain a proper adhesion of the zinc and
iron or steel as hereinbefore described. I also, by preference, cause the solder or
suitable alloy used for attaching them to take a peculiar form or be shaped into
what may be termed "hollow rivets," or "flanged," or "collared," washers, or other
suitable form for the position in which they are to be used, either by casting or
moulding them into shapes by the aid of a press and dies or other suitable means,
in order that by that form and the use of the flame jet I may be enabled to secure
more perfect action of the heat on the plates or parts to which the sheet zinc is to
be attached on the solder or alloy which attaches them, the hole or aperture being
sufficiently large to admit of the flame jet first attacking the iron or steel plating
in order to raise it to the required temperature before the solder, washer, or part,
or attaching alloy melts, and on the zinc sheet itself, which is attached by the
process during its operation, and the mode I adopt, by preference, for applying the
heat is that of a jet of gas or suitable vapour flame, such as, for example, that
available by a modification of the apparatus invented by Count de Richemont, and
patented in England by M. Delbruck in Patent No. 8024, of 1840, the apparatus
for generating the gas being more particularly described and illustrated in the
Patent granted to L. Hebert, No. 7659, of 1838, or any other equivalent method or
arrangement suitable for the purpose.
I am aware that soldering metal sheathing to iron ships has been proposed before,
and that in the year 1862 Provisional Protection, No. 1503, was obtained by
Joseph Needham for the use of this plan, but he caused the "suitable metallic
sheathing" to adhere by "soldering it over its entire surface," and by so doing the
exclusion of the sea water from access to the inner surfaces of the "suitable
metallic sheathing," and the exterior surface of the iron hull to which it was to be
attached would result, and the amount of galvanic action which is desirable to be
obtained for the prevention of fouling, although not so necessary for the preserva-
tion of the iron, would thereby be prevented to a certain extent.
By my improved method it will be seen that I avoid this difficulty, and at the
same time obtain an efficient means of attachment, and thus combine the advantage
of obtaining the two objects in one operation.
It may be observed that in the case of soft soldered joints a blow of the hammer
or any accidental violence is almost certain to break the joint asunder so long as
the joint is weaker than the metal generally, and therefore the joint is only safe
where one of the metals from its thinness is no stronger than the solder, so that
the two may yield in common to any disturbing causes, and in general the hard
solders are made of the self same material which they are intended to join, but
with a small 'addition of a inore fusible metal, and that the soldering tool or copper
bit is only applicable to thin metals because it requires such a degree of heat as will
allow it to raise the temperature of the work to be joined to the melting point of
the solder, but with the "aero hydrogen blow-pipe" it is easy to maintain any
required temperature for an indefinite period, and to render the flame jet oxidating
or reductive at will by burning hydrogen, either pure or mixed, in any ratio with
air by adjusting the stop cocks attached to the apparatus or blow pipe, the oxidating
flame jet produced by a preponderance of the air blast may be used for raising the
temperature of the metals, but the reductive flaine jet produced by a preponderance
of the hydrogen gas is desirable to ensure a sound junction of the alloy with the
ir or steel and the zinc. And by any method or arrangements by punching or
for.ning sufficiently large holes or apertures in the sheathing the iron or steel
plating at the part to be united to the zinc or electro positive alloy sheathing may
be readily raised to the required temperature without risk of previously melting the
attaching alloy or the metal used as a sheathing. I may also observe that in
attaching zinc sheathing to the iron or steel plates of a ship or steam vessel or
other submerged or partially submerged fixed or floating structure the solder should
be of a less electro positive character than the zinc, so that its endurance chemically
may be greater, which result may be obtained by an alloy composed of tin and
zinc.

page_text: Having cut the zinc sheet to fit the dimensions and shape of the place or part it
is to occupy I punch or otherwise form around its edges a row or rows of holes, or
I may punch in the edges and butts of the zinc or other sheets used as the sheathing
half holes or openings opposite similar half holes or openings in the adjoining edges
and butts, the sheets when placed in position forming complete holes of any suitable
or required size and form, and at any required or desired distance apart, into which
I insert the flanged washer or attaching part or parts hereinbeforo described, and I
also form such other holes or openings as may be decided on in the "bunt" or
middle portions of the sheet, and then having placed the sheet on or against the
place or part it is to occupy, I, with a piece of tube, cork, or other suitable material
dipped in white paint, chalk, or whitening and water, or other convenient and
suitable colouring or marking material, mark through each hole on the surface or
part of the iron or steel the position of the same, so as to shew what part of the
iron or steel each "flanged collared washer," or "hollow rivet," or other attaching
portion will come in contact with, and having completed the marking the sheet is
taken down, and those parts shown by the marks on the iron or steel having the
surface clean from paint, grease, dirt, or rust are then further cleaned with spirits
of salts, or by a rasp or file, or by scraping and filing, and washing with spirits of
salts, or a dilute solution of the same, and a suitable soldering flux (chloride of zinc)
applied to prevent oxidation and capable of causing or aiding the adhesion of the
solder or alloy to the iron or steel. Whilst this is being done another person may
be employed in cleaning where needed, and moistening with muriatic acid or a
dilute solution of the same the surface of the sheet zinc on the side which comes in
contact with the iron or steel, round the surface of each hole, and inserting in each
hole a "flanged collared washer," or "hollow rivet," or other attaching part (pre-
viously dipped in a suitable flux) so that the projection or part on the flange or
head of the hollow solder rivet shall be in the punched hole in the zinc sheet, and
then all the holes being properly supplied with such alloy or solder the zinc sheet is
to be returned to and kept firmly in its place, and the flange of the washer, or head
of the "hollow rivet," or other attaching part being pressed against or kept in
contact with the prepared parts of the iron or steel, and then by causing the flame
jet to play into the hole of the flange, or hollow solder rivet, or other attaching
part, and through the hole in the zinc sheathing, the iron or steel at the desired
part becomes sufficiently heated, the solder or alloy melts and adheres to the metals
and a few sweeps of the flame jet over the exterior surface of the zinc sheet round
each hole or attaching part during the process where the solder or alloy is used
finishes the melting and, on cooling, leaves the sheet of zinc firmly attached to the
iron or steel. It will be found an advantage if, on completing the soldering at each
hole and before the solder or alloy sets, tho zinc sheet is pressed up to or against
the iron or steel by means of a hammer or other suitable or convenient means of
securing the close contact of the two metals, whereby a very complete job will be
made.
In some cases I may insert the attaching solder or alloy after having raised the
temperature of the iron or steel to nearly the required degree of heat, so as to avoid
the risk of melting the solder or alloy before the iron or steel becomes sufficiently
heated. It will be inanifest that in certain cases in place of putting the solder or alloy
on the zinc or other metal sheathing, used as above described, it may be attached to
the iron, steel, or other metal plates or portions, and the heat applied as above
described, their positions being previously marked by the aid of a template or its
equivalent both on the metal to be attached and the metal to which the attachment
is to be made.
In certain cases, in place of punching holes at the edges of the sheet zinc or other
suitable electro positive metal or alloy, I may form the solder or alloy attaching
portion or portions so as to be applied to and secure the "butts" or end edges of
the plates either entirely along their length or only partially, as may be desired or
preferred, and the top and bottom edges of each sheet may be attached in a similar
manner by a similar or suitable arrangement of the solder or alloy attaching part

page_text: or parts, where it is desirable only to attach the zinc sheathing together, zine to
zinc; or I may punch at the edges and "butts" of the zinc sheets half holes
opposite similar half holes in the adjoining edges and "butts," the sheets when
placed in position forming complete holes of any suitable or desired form or dimen-
sions, as herein before described, into which I insert the flanged washer or suitable
attaching part or parts, hereinbefore described, for attaching to the iron or steel,
and join together intervening space, zinc to zinc, as above described.
In the case of new vessels I may adopt the system of plating proposed by
Mr. T. B. Daft in Patent No. 2331 of 1863, for retaining compressed teak or other
suitable material between the edges and butts of the iron or steel plates, and attach
the edges and butts of the sheathing, securing the "bunt" or middle portion of the
sheets used as a sheathing with the attaching alloy and the aëro hydrogen blow
pipe and apparatus, as hereinbefore described.
At the top, bottom, and ends or termination of the strakes of sheathing I may
apply a thicker portion of zinc, galvanized iron, or other suitable material capable
of being readily attached by solder, or alloy, or otherwise, both to the iron or steel
plates and the sheathing, and so formed as to act as a fender or guard to the ends,
edges, or termination of the sheathing, and prevent as far as possible any liability
to hitching or hanging on to the same of such things as might come in contact with
the ends, edges, or terminations, and cause the samne to become detached or partially
detached. This thicker portion may be of any required or desired length, breadth,
or thickness, or suitable form, according to the circumstances of the case or the
desire of those for whom the work is executed, at the sheathing line; above the
load water line it may take the form of that shewn in the Patent No. 2143 of 1867,
granted to one M°Intyre.
When the autogenous process is adopted, suitable holes are punched in the sheets
where desired, the iron or steel to which the sheet or sheets are to be attached
is marked, cleaned, and fluxed as hereinbefore described, the sheet is then placed
in the position it is to occupy and the flame jet applied. This process is however
most conveniently and properly confined to joining the edges or "butts" of the
zinc sheet, each to cach throughout their entire length or portions only of their
length, and by preference I use for this purpose a strip of the solder or alloy of
an angle or form, being more readily fused than zinc.
After the sheets of zinc or other electro positive metal as a sheathing have been
fixed in their places by the necessary or desired attachments hereinbefore described,
I remove any roughness at the attachments or joints or fill up any vacancies by the
aid of a suitable soldering iron or bit, such as that described in the diagrams, and
marked F, thus making the sheathing an uniform and even surface. The alloy
used as a solder or attaching part for the purposes herein before described should be
electro positive to iron or steel, but in a less degree and more fusible than zinc or
other electro positive sheathing an alloy composed of four atoms of zinc to one of
tin (260-8 zn. to 118 sn.), although a higher ratio of zinc to tin, or vice versa, may
be used, or any other equivalent alloy, the object being to obtain not only a
mechanically strong joint or junction, but one more enduring chemically than the
zinc or other electro positive sheathing.
The iron or steel to be sheathed with zinc should be bare and free from grease or
paint, and the galvanic action set up should be such as to cause the zinc to oxidize
or exfoliate at about the rate of from one ounce to three ounces per square foot per
annum, and the rate of oxidation or exfoliation of the zinc when excessive may be
reduced by the interposition of a non conducting medium, such as paint or marine
glue applied to the surface of the iron or steel before the zinc sheathing is attached.
The rate at which the zinc is allowed to oxidise or exfoliate will govern to a certain
extent the thickness for endurance of the sheet zinc to be used, that suitable for
general use being the gauge No. 15 zinc guage, equal to 24 ounces per square foot
though of course where desired thicker or thinner sheet zinc inay be employed.
Pure zinc will be found to wear more evenly than the lower priced and less pure
qualities, and for this purpose the sheet zinc of the Vieille Montagne Zinc Company

page_text: will be found to give the most satisfactory results, although it is obvious other
sheet zinc inay be employed.
It will be obvious also that the process of metal attachments hereinbefore
described is applicable for attaching sheet metals, or parts, or sheet metal, or more
solid metals or parts, such as the linings of boilers, tanks, cisterns, as well as to the
inside plating and framing of iron or steel ships and vessels, buoys, piers, columns,
etcetera.
The accompanying Sheet of Diagrams will shew how the sheets of zinc may be
attached, and the manner in which the holes and solder or alloy, flanged washers,
hollow rivets, or attaching parts may be formed and applied, and also an improved
plan or mode of arranging and forming the gas blow pipe apparatus, and “soldering
bit" used in carrying out my Invention.
Figure 1 shews a portion of the sheet zinc sheathing arranged in accordance with
my Invention, with the apertures formed in or on the edges and butts, as well as in
the "bunt" or central portion of the sheets. The apertures may be round, or
square, triangular, or any other suitable form, and the attaching alloy or solder
suitably formed accordingly, providing about a square half inch area of aperture
more or less, according to circumstances. The zinc sheathing between the attach-
ments at the apertures may be united together by the process herein before mentioned.
A, A, the zinc shects; B, B, apertures at the edges and butts; C, C, apertures in the
bunt or central portions of the sheets.
Figure 2 shews in front view at a and in sectional edge view at b one of my
alloy or solder flanged washers, or hollow rivets, or attaching parts, as herein before
described. In this case it is shewn round, though it may be square, triangular, or
any other suitable and desired form, and instead of the flat part being a complete
circle it may be cruciform, as shewn by the dotted lines.
Figures 3 and 5 are forms suitable for edge, butt, and square holes.
Figure 4 is a form suitable for joining together the butts or joints of the zinc
sheathing.
Figure 6 shews in longitudinal section the improved gas jet blow pipe herein-
before mentioned. A is the wooden handle; B, B, the outer pipe, through which
the hydrogen gas passes; C, C, the inner pipe or tube for the passage of the air
blast; D is the pointed nozzle to the outer pipe; E, the pointed nozzle to the inner
pipe C, both of which may be straight, as shewn, or beat or cranked if desired, or
moveable, and may be attached by a screw joint or bayonet joint, or a slot and
pin. These nozzles may be detached, and the soldering iron or bit F, Figure 7,
attached, which will be found useful for reconciling any roughness remaining at the
attachments. G and H are stop cocks for regulating, controlling, and adjusting the
supply of gas and the air blast; I, K, screw connexions for attaching the flexible
tubing from the air and gas apparatuses.
A single pipe may however be used with gas and air, having been previously
mixed at the junction of the tubing, as shewn attached to gas apparatus in the
Drawing of the Patent No. 7569 of 1838, granted to Luke Hebert.
Figure 8 shews in section an apparatus that may be used for generating the
hydrogen gas with the flexible pipe for leading the gas to the improved blow pipe,
Figure 6.
Figure 9 shews in elevation a bellows that may be used for producing the blast,
and the flexible pipe or tube for leading the air from the same to the improved
blow pipe, Figure 6.
Having now described the nature of the said Invention and the manner in which
the same is to or may be performed or carried into practical effect, I desire to state
that I do not limit or confine myself to the precise details as hereinbefore specified
and illustrated in the accompanying Sheet of Diagrams, as the same may be modified
without departing from the nature of my said Invention, nor do I claim as of my
Invention the application of sheet metallic zinc or other electro positive metal or
alloy to iron or steel structures for the prevention of corrosion and fouling of the
same, as this is not new; nor do I claim as of my Invention the use of solder for

page_text: attaching the sheathing by the aid of beat to the iron or steel structure, as this is
not novel; but what I do claim as of my Invention and desire to have protected
by Letters Patent is,―
First. The method and arrangements herein before described of attaching sheet
metallic zinc or other electro positive metal or alloy as a sheathing to iron or steel
ships, or vessels, or structures, by a suitable alloy applied in parts or patches, as
herein before described and illustrated in the diagrams, and also in the case of new
vessels, in combination with the plan of edge and butt fastenings patented by
T. B. Daft, in Patent No. 2331, of 1863.
Second. The mode hereinbefore described of making such metallic attachments
by the aid of the aëro hydrogen blow pipe apparatus, in combination with
sufficiently large apertures in the sheathing at the desired points of attachment for
the purpose of enabling the iron or steel plating behind the sheathing at
the desired parts to be raised to the required temperature.
Third. The use of an electro positive alloy of a less electro positive character, and
inelting at a lower temperature than the sheathing as the attaching part, for the
purposes hereinbefore described, substantially as and for the purposes herein before
described.
Fourth. The form and arrangements of the attaching alloy, substantially as and
for the purposes herein before described and illustrated in Figures 1, 2, 3, 4, and 5
in the accompanying diagrams.
Fifth. The improved form and arrangement of the blow pipe to be used with the
aëro hydrogen apparatus, applicable also in combination with claims 2, 3, and 4, for
use in joining together other metal parts, as herein before described and shewn in
Figures 6 and 7 of the diagrams.
In witness whereof, I, the said Charles Frederic Henwood, have hereunto set
my hand and seal, this Twenty sixth day of November, in the year of our
Lord One thousand eight hundred and seventy nine.