AN IMPROVED SEAM TO BE USED IN LAUNCH AND BOAT BUILDING WHEREBY THE NECESSITY FOR CAULKING IS OBVIATED
Year: 1884

page_text: PROVISIONAL SPECIFICATION..
I GEORGE JOHN TAGG of the firm of T. G. Tagg & Son of the Island Boat
building Works, East Moulsey in the County of Surrey Boat & Steam launch
builder do hereby declare the nature of my invention for "AN IMPROVED SEAM TO
BE USED IN LAUNCH AND BOAT BUILDING WHEREBY THE NECESSITY FOR CAULKING
IS OBVIATED" to be as follows:-
The object of my invention is an improvement in the mode of producing a water
tight deck upon launches, ships, and in all places where such decks are required.
It is well known that in the present state of deck caulking, that is, with tow or
other fibre, driven home with the ordinary type of caulking tool, great injury
results to the fibre of the wood employed in such work owing to the blows of the
caulking tool, in addition to this and other evils of the present system, the most
prominent may be cited, namely, the fact that in all descriptions of caulking now
in use the damp is most liable to lodge, either during caulking or subsequently from
below, also the unsightliness of the present seam may be mentioned.
In order to carry out my improved method of making joints in the decks of
vessels and other places I make the sides of the planks tolerably true and having
cut coarse linen, or canvas, into suitable lengths, about the depth of the planks to
be operated upon, I soak them in a solution of red lead, varnish, and waste paint in
proportions to be hereafter defined, this strip I place between the timbers to be
operated upon, and having applied heavy pressure and having secured the deck in
the usual way it will be found to produce a thoroughly water tight joint and will
afford none of the unsightly seams at present visible with the ordinary caulked
joints, now in use, it will also be obvious that it will be practically unaffected by
change of temperature and climate:*

page_text: I, GEORGE JOHN TAGG, of the firm of T. G. Tagg & Son, of the Island Boat
Building works, East Moulsey, in the County of Surrey, Boat & Steam Launch
Builder, do hereby declare the nature of my invention for "AN IMPROVED SEAM TO
BE USED IN LAUNCH & BOAT BUILDING WHEREBY THE NECESSITY FOR CAULKING
18 OBVIATED," 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 my invention is the introduction of an improved method of caulking
the seams of launches and boats.
My improved seam is applicable to the sides of the boat, as well as to the deck,
its simplicity and utility making it applicable under any circumstances where it
has hitherto been the practice to make a joint in boat-building by caulking.
It is well-known that with the ordinary system of caulking seams with tow, or
similar fibre, driven into the joint with an ordinary caulking tool, the edges of the
timbers suffer considerable injury from the blows upon the tool. Moreover, damp
easily finds a lodgment in the caulking material used, either at the time of making
the joint or shortly after, and, at the best, such a joint is always more or less
unsightly.
In carrying out my invention I abandon the use of the ordinary caulking tool
and caulking together, and substitute my improved method, hereafter described.
In order that my invention, and the means by which the same can be carried
into effect, may be thoroughly understood, I will proceed to describe the same in
detail, referring in so doing to the accompanying drawings which are to be taken
as part of this specification and read therewith, and in which like parts are marked
throughout the figures in which they occur with the same reference letter.
Fig. 1 is a sectional elevation shewing my invention as applied to the side of a
boat, and Fig. 2 is a plan shewing its application to decks, although I would have
it distinctly understood that the scope and applicability of my invention are not
confined to the making of side seams only, inasmuch as said invention is applicable,
with advantage, to making deck seams generally. Fig. 3 is a section of a seam, on
a larger scale.
The edges of the planks, a, are left tolerably true, but not necessarily finished
with exact truth. This inequality of surface enables the planks to gain and keep a
better hold upon the caulking material. The material I use is coarse linen, or duck,
in strips-in width about equal to the thickness of the planks, and of the length of
the seam.
These strips, l, are single double, or manifold, as the thickness of the
planks and length of the seam may render advisable. When used double, the
fold, c, is always at the bottom of the seam, or inside the boat, the two edges d, d,
of the material projecting upwards or outwards. They are prepared by soaking
them in a solution of red lead, varnish, and waste paint, or instead of the above
mixture, copal varnish may be used with advantage, the strips being soaked to
saturation,

page_text: The strip is then held in position against one edge, (or between two planks), and
the one plank forced up against the adjoining one by the necessary degree of
pressure exerted in the required direction by any convenient means.
When the
planks have been approached as closely as is necessary, they are secured to the
cross timbers in the ordinary way.
In consequence of the natural elasticity of the canvas, or duck, which is increased
by the soaking before described, and the adhesive properties of the latter, a perfectly
air-tight as well as water-tight seam is produced without delivering a single blow
upon the planks or, in any way, exerting any pressure upon them capable of
crushing or distorting their fibres. In addition to this, the contraction of the
wood, due to heat, is compensated for in the same ratio by the elasticity of the
86am.
The protruding edges of the canvas are shaved off, leaving the general surface
smooth and the seams sightly. Any further protrusion, due to swelling of the
canvas, or duck, under the influence of moisture, will manifest itself under the
deck or inside the boat's side, where the fold, c, is. Thus, by placing the fold under,
or inside, as illustrated, due provision is made for protrusion without unsightliness.
My improved joint is, from the durable and elastic nature of the materials
employed, unaffected by changes of temperature and climate.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
In making an air- and water-tight joint between two boat-joint planks, the
insertion of a single, or multiple, fold of duck, or canvas, previously soaked as
herein before set forth, between two adjoining timbers, the whole substantially as
described with reference to the accompanying drawings,
Dated this 18th day of May 1885.
PHILLIPS & LEIGH,
Patent Agents,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.