A NEW MODE OP UNITING TOGETHER OR PLATING TIN UPON LEAD
Year: 1820

page_text: DOBBS SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
DOBBS, of Smallbrook Street, Birmingham, in the County of Warwick, Plater,
do send greeting.
WHEREAS His most Excellent Majesty George the Fourth did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Ninth day of December,
in the first year of His reign, grant unto me, the said Thomas Dobbs,
my executors, administrators, and assigns, His special licence, full power,
sole priviledge and authority, that I, the said Thomas Dobbs, my exe-
cutors, administrators, and assigns, should and lawfully might make, use,
exercise, and vend, within that part of the United Kingdom of Great Britain
and Ireland called England, His Dominion of Wales, and Town of Berwick-
upon-Tweed, my Invention of "A NEW MODE OP UNITING TOGETHER OR PLATING
TIN UPON LEAD," for the term of fourteen years from the date of the
said Letters Patent; in which Letters Patent there is contained a proviso
obliging me, the said Thomas Dobbs, under my hand and seal, to cause a
particular description of the nature of my said Invention, and the manner in
which the same is to be performed, to be inrolled in His Majesty's High Court
of Chancery within two calendar months next and immediately after the date
of the said Letters Patent, as in and by the same, relation being thereunto
had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Dobbs, do hereby declare that my Invention of a Mode of Uniting
together or Plating Tin upon Lead is fully described and ascertained in manner
following (that is to say):
First, in order to unite tin with leaden pipes, or to coat, cover, or plate
them with tin, I take the pipe hot from the mould in which it has been cast,

page_text: and lay it horizontally upon a bed of hurds, rags, or tow, which has been
previously prepared or impregnated with turpentine or other resinous substance,
a small quantity of melted tin having been also previously put on the said bed of
hurds, rags, or tow. I then rub the outside surface of the pipe with hurds, rags,
or tow, prepared or impregnated as aforesaid with turpentine or other resinous
material, until the surface of the pipe is completely tinned. I then attach to
the end of a rod or wire a bunch of hurds, rags, or tow, prepared or impregnated
as aforesaid with turpentine, and introduce it withinside the pipe, together with
a little melted tin, and work the-bunch up and down in manner of the piston of
a pump until the inside is also tinned. I then place or fix the pipe in a larger
pair of moulds, so as to leave a vacancy between the pipe and mould; and I
also introduce or fix a small core into the centre of the lead pipe, leaving a
vacancy also between the pipe and the core. I then take melted tin out of a
furnace, and. with a ladle I pour the tin down the two vacancies before men-
tioned, by which means the two bodies are perfectly and soundly united, and
the lead pipe is united or plated, both inside and outside, with a thick coating
of tin. In this state it is then ready for drawing or rolling, whichever may
be the most convenient. It is not necessary that the tin should be quite pure
to be united to lead by this mode, but it may be alloyed with other metals.
The moulds and cores I use are the same as those generally employed by lead
pipe makers, excepting that I prefer them made of copper or brass instead of
wrought and cast iron, of which materials they are most commonly made.
Secondly, in order to unite tin to lead blocks or ingots, or to plate them on
one side, I take a block or ingot of lead, while in a hot state, from the mould
in which it has been cast, and I rub a little tin and turpentine, or other
resinous material, over the side or part intended to be plated with burds, rags,
or tow, or other similar soft material. I then place it in another mould made
of copper or brass, or other proper material, sufficiently large to leave a vacancy
between the mould and the side of the block or ingot of lead which has been
previously tinned. I then pour melted tin into the vacant space, so as to fill
up the said vacancy, and the block or ingot when cold is fit for use.
Thirdly, in order to unite tin to ingots of lead, or to plate them on both
sides, I rub a little tin and turpentine or resin on the block or ingot of lead
while hot from the mould in which it was cast, with hurds, rags, or tow, over
the sides of the said block or ingot intended to be plated. I then place the
block or ingot in another mould, larger than the one in which it was cast, so
as to leave vacancies between the mould and the two sides of the block or
ingot which have been tinned. I then pour melted tin into the said vacancies
as before described, by which means the two metals become united, and the

page_text: moulds giving the size and dimensions of the block or ingot required, they are
ready to be wrought. My reason for tinning the pipes and ingots previously
to casting the tin in the moulds upon the lead, is in order to make the two
bodies, unite soundly together. The plating may be effected when the lead is
cold, and without previous tinning, but I prefer following the course above
described.
Fourthly, in order to plate or unite tin with lead sheeting, I place a sheet
of lead upon a hot stove until it is made of a sufficient heat to keep the melted
tin, which I pour on the surface in a fluid state. I then throw a little rosin,
turpentine, or other resinous material, upon the sheet, and when the same is
melted, with a greasy rag or hurd or other similar soft substance, I rub the
tin and resin, turpentine or other resinous material, over the lead sheeting
until the lead sheeting be completely tinned. I then wipe off such tin as may
not have adhered; or the tin can be put upon the lead in a small body, and in
a cold state, and with the heat of the lead and the help of resin it will make
the tin flush or melt.
In witness whereof, I, the said Thomas Dobbs, have hereunto set my
hand and seal, this First day of February, in the year of our Lord
One thousand eight hundred and twenty-one.
AND BE IT REMEMBERED, that on the First day of February, in the
second year of the reign of His Majesty King George the Fourth, the said
Thomas Dobbs came before our said Lord the King in His Chancery, and
acknowledged the Instrument aforesaid, and all and every thing therein con-
tained and specified, in form above written. And also the Instrument afore-
said was stamped according to the tenor of the Statute made in the fifty-fifth
year of His late Majesty King. George the Third.
Inrolled the Seventh day of February, One thousand eight hundred
and twenty-one.