Improvements in the Coating or Covering of Exposed Wooden Structures or Timbers.
Year: 1889

page_text: Date of Application, 11th Nov., 1889-Accepted, 14th Dec., 1889
COMPLETE SPECIFICATION.
Improvements in the Coating or Covering of Exposed Wooden
Structures or Timbers.
A communication from abroad by GEORGE PHILLIPS, Superintendent of Public Works,
United States Engineer Department, of Fort Taylor, Key West, in the County of
Monroe, and State of Florida, United States of America.
I, JOHN CORRY FELL, of the firm of Fell and Wilding, of 1 Queen Victoria Street,
in the City of London, Patent Agents, 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:-
My invention, herein set forth, is an improvement in the coating of exposed wooden
structures, or timbers, for the purpose of protecting them from decay or the attacks
of insects. It is specially designed for piles and other articles or structures of
wood, which are exposed to the attacks of the teredo navalis, and other marine
insects.
The main feature of the invention lies in the formation of a hard stony covering
upon the wood, impenetrable to the attacks of insects; but it includes also the
necessary elements of firm adhesion to the wood. the toughness or strength in the
material of the covering; and further for the preservation of the wood from decay, it
includes also impenetrability to water. While I have used my invention for the
greater part upon piles exposed in water to the attacks of insects, it is equally
applicable to the bottoms of ships, and to timbers, such as railroad ties, exposed only
to the weather.
My invention consists of a covering for wood composed of the materials hereinafter
specified and applied in the order described, and it consists also in the method of
application of the materials.
For the first coat of the covering applied to the pile or other wood surface, I use
asphalt, preferably that of the Val de Travers, and this may be used alone, or thinned
by the admixture of mineral tar, or like material.
The asphaltum is applied directly to the surface of the wood. When round logs are
used, the bark should first be removed. My mode of application of the first cont
consists in melting the asphaltum by heat, (care being taken not to scorch it) and
when it is of the consistency of thick paint apply it directly and while hot to
the surface of the wood. This may be done by means of a brush or by immersion
of the wood. One or more such coats may be applied, in the same manner, to secure
any required thickness. This layer of asphaltum applied in a liquid condition, and
especially if applied while hot, adheres strongly to the wood and possesses the
qualities of toughness and impenetrability to water, but this alone does not constitute
my invention, nor secure all or the main objects 1 have attained. The asphaltum
alone will not resist the attacks of marine insects nor sufficiently the influences of the
atmosphere and requires a harder exterior surface than that which its own material
affords. This hardening of the surface I have secured by the application of an
indurating material, to the exterior surface of the asphaltum. The material which I
use for this purpose is unslacked lime. This I apply while it is hot, by sifting or
sprinkling it, in a pulverized condition, over the surface of the asphaltum. I have
used for this purpose, with excellent effect, a kind of sand found in Florida, in
the United States of America, consisting of decomposed shells and coral. which is
first en eined and applied while hot as above described. Any calcareous material
may be used, and when applied while still in a heated and pulverized condition, it
is absorbed by, or sinks into, the asphaltum and combines therewith, indurating the
surface so that, underneath, the covering has the tenacity and tongliness of the
asphaltum, and on the exterior a hard stony surface, and combines in a single coat
i

page_text: all the qualities required for strength, permanency of adhesion, and resistance to the
elements and the attacks of insects.
For the best effects pure unslacked lime is used, but inert materials such as cilicious
sand may be mixed therewith in small portions, to save expense, but inert materials
such as cilicious sand cannot be used alone, and so used in place of the lime are not
included in my invention.
The invention may be modified by the interposition of a layer of fabric of any
suitable kind such as canvas or wire cloth. After the asphaltum is applied directly to
the wood, as above described, a strip of such fabric is wound or applied over it, and
tacked firmly with flat headed nails of some incorrodible material. Over this is
applied another coat of asphalt, in the manner above described, and the exterior
surface of this is hardened by the application of lime, as hereinhefore explained.
The forms of coating above described are capable of application to piles, any form
of timber, or to ship bottoms.
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. A covering for piles, timbers, and wooden surfaces generally, said covering
consisting of asphaltum having its exterior surface hardened by combination with lime,
and either with or without an interposed fabric, all substantially as described.
2. The method of covering wooden surfaces, consisting in first applying asphaltum
to the wood, and then applying to the surface of the asphaltum coating, pulverized
lime, and either with or without the interposed fabric, all substantially as described.
Dated this 11th day of November 1889.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.