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remove an alkaline paint stripper, failure to remove grease, inadequate stirring, efflorescence
due to water inleakage, excessive moisture content of plaster, poor drying due to
wax derived from a paint stripper, blackening due to a lithopone paint applied over old
lead paint.
Many investigations of various aspects of paint and painting were made and a few
examples are :
Paint removers—Recommendations were made to avoid using the alkaline types
owing to the difficulties encountered and, in addition, care was advised that the methylene
chloride types were only used where adequate ventilation could be provided.
Epoxy resins—Paints which incorporated these newly developed resins were
examined and experiments were made on a large scale. It was considered that the
difficulties of application of the brands tested were such that further commercial
development was required before the products were suitable for normal Council work.
Silicone paints—Many experiments were made to utilise these high temperature
paints (up to 900°F.) but, in general, unless the painted surface could be uniformly
heated to the correct ' setting ' temperature they were not successful. This precluded
their use on some exhaust pipes and steel chimneys.
Emulsion paints—A report on these products was issued to user departments through
the paint sub-committee pointing out that basically there were three types, polyvinyl
acetate, polystyrene and alkyds, which had different properties, and details were given
of these, e.g., resistance to alkali, resistance to the bleeding through of creosote or
bitumen, resistance to washing, porosity to water vapour, behaviour under condensation
conditions, outdoor durability.
On approval these products were classified under their respective types so that easy
reference could be made to their properties.
Aqua paint—It was claimed by the manufacturer that, by adding a quantity of a
proprietary liquid (found to be a substituted tertiary amine of the quaternary type)
to a paint, wet materials could be painted successfully. This claim was not found to be
substantiated.
Amongst other matters investigated were anti-condensation paints, stoving enamels,
rust removers, the painting of Bellrock plaster (which owing to its nature presents
many difficulties), coating of balsa wood, zinc sprayed ironwork, etc.
During the year advice was given to four other local authorities and to the British
Standards Institution on painting questions and the Ministry of Defence granted
permission to the Council to use and quote their recent D.E.F. specifications.
The revision of Painter Specification Clauses for the Architect's Department was
undertaken and a committee was appointed consisting of officers of that department
and of the chemical branch. After 18 meetings new specifications were put forward
especially for primers for iron, steel, zinc and aluminium, etc. Thus considerable improvement
was accomplished particularly in the requirement for the priming work, on which
the rest of the paint system so vitally depends.
Building materials and allied problems
This section of the work again expanded considerably and its complexity increases
yearly with the introduction of new materials and new methods of building construction.
Of the materials regularly examined in order to determine whether or not they complied
with British Standards or other specifications, mention can be made of asphalt (for
roofing, flooring, paving, etc.), bitumen felts (for dampcourses, roofing, flashing or
tanking), cements, mortars, plasters, jointless flooring, etc. Many other products which
might be of use to the Council were examined and tested critically to assess their quality
and behaviour: items in this category included coated hardboards, resin-bonded
chipboards and laminated boards, fire-resistant and insulating constructional materials,