Improvements in Covering Lead Surfaces to Protect Water and other Potable Liquids in Contact therewith from Contamination
Year: 1893

page_text: Date of Application, 29th July, 1893
Complete Specification Left, 12th Apr., 1894-Accepted, 14th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in Covering Lead Surfaces to Protect Water
and other Potable Liquids in Contact therewith from
Contamination.
ALEXANDER MCDOUGALL Gentleman 61 Liverpool Road Birkdale Southport.
I do hereby declare the nature of this invention to be as follows:-
-:
Water or other potable liquids when conveyed through lead pipes or otherwise
brought into contact with lead surfaces are liable to contamination by the solution
of the motal.
This soluble metal is an oxide formed by the chemical action of the aerated
liquids upon the lead.
Water or other potable liquids so contaminated are not wholesome for drinking
or any culinary use.
To preserve water or other potable liquids from such contamination they must
be protected from contact with lead surfaces.
The object of my invention is to protect water and other potable liquids from
contact with lead and so preserve them from such contamination.
This I effect by coating the interior surface of lead pipes and other lead surfaces
with which water or other potable liquids may be brought into contact with a
preparation insoluble therein and not liable to chemical change in contact
therewith.
The materials I use are a preparation of cotton-seed-pitch dissolved in bisulphide
of carbon mixed with about an equal quantity of caoutchouc dissolved in naphtha
or other volatile solvent. These solutions when mixed in about the above
proportions yield a liquid which coats lead surfaces and on exposure quickly
solidifies on the evaporation of the volatile solvents leaving the lead with a covering
insoluble in water or other liquids and not liable to chemical change in contact
therewith.
Dated this 29th day of July 1893
.
COMPLETE SPECIFICATION.
Improvements in Covering Lead Surfaces to Protect Water
and other Potable Liquids in Contact therewith from
Contamination.
I ALEXANDER MCDOUGALL Gentleman 61 Liverpool Road Birkdale
Southport 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 :-
Water or other potable liquids when conveyed through lead pipes or otherwise
brought into contact with lead surfaces are liable to contamination by the solution
of the metal.
This soluble metal is an oxide formed by the chemical action of the aerated
liquids upon the lead.
Water or other potable liquids so contaminated are not wholesome for drinking
or for any culinary use.

page_text: To preserve water or other potable liquids from such contamination they must
be protected from contact with lead surfaces.
The object of my invention is to protect water and other potable liquids from
contact with the lead and so preserve them from such contamination.
This effect by coating the interior surface of lead pipes and other lead
surfaces with which water or other potable liquids may be brought into contact
with a preparation insoluble therein and not liable to chemical change in contact
therewith.
The materials I use are, a preparation of cotton-seed pitch dissolved in bisulphide
of carbon mixed with about an equal quantity of caoutchouc dissolved in naphtha
or other volatile solvent. These solutions when mixed in about the above
proportions yield a liquid which coats lead surfaces and on exposure quickly
solidifies on the evaporation of the volatile solvents leaving the lead with a covering
insoluble in water or other liquids and not liable to chemical change in contact'
therewith.
The manner in which I coat the interior surface of lead pipes is to fill them
with solution prepared as above and after a short interval to drain off the excess
when a sufficient portion adheres to the metal to form a covering which protects
it from contact with the water.
The pipes may be operated upon either in coil or when placed in a perpendicular
position, but I prefer the latter as the result is a more uniform covering than
when treated in coil.
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
I. The use of carbon bisulphide to dissolve cotton pitch as a component of my
solution.
II. A solution of caoutchouc in naphtba or other volatile solvent as another
constituent &
III. The mixture of the two solutions to form my preparation to coat lead
surfaces.
Dated this 13th day of April 1894
A. MCDOUGALL.