July_1971 — Page 47

materials and equipment

PAINT STRIPPER

Paint and varnish can be removed from buildings or delicate furniture mouldings with a stripper claimed by its makers to cause no damage to the surface beneath. The preparation can also be used to remove paint from metals except galvanised or alumi- nium surfaces.

-

The substance is supplied in the form of a paste and is simply spread thickly over the surface, left for an hour or more, depending on the thick- ness of the paint, then scrubbed or hosed off with water.

When applied to timber, the strip- per works in two ways. First it dis- solves the paint and varnish down to the grain, then a poultice action begins

Poultice action removes all paint

to draw the paint out of the grooves and knotholes. It is non-flammable and odourless.

The makers are Inter-Strip Hold- ings Ltd., 31 Hills Road, Cambridge, CB2 1 NW, UK.

FIRE DOOR STAY

The Briton 999 fire door stay has been produced to suit doors which have been designated by the fire of ficer as 'self closing' yet are often wedged open by the building user.

The stay is connected to the alarm/ detector system and will hold doors open for normal use, releasing them in the event of fire. It incorporates an electro-magnet which is wired into alarm/detector systems and holds the

door open.

The door remains open, unless:

Far East BUILDER, July 1971

a. The alarm is set off either manually or by smoke or heat sensitive devices as approved by the fire officer. This is accomplished through a relay

Briton 999 fire door stay

Slide (Tufnol)

Säide Buffer Pad (Foam Rubber)

Electro Magnet

Side Disc (Steel)

break switch which will interrupt the circuit allowing the door to close auto- matically.

b. There is a power failure or other interruption to the supply, in which case as a precaution the door will be released to close automatically.

c. The door is closed manually (the electro-magnet allows easy release without damage to the unit).

William Newman and Sons Ltd., Hospital Street, Birmingham 19, are the makers.

CONCRETE PANEL PROCESS

A new industrialised building pro- cess developed in Britain allows scope in design and depends on the produc- tion of big concrete panels in a variety of shapes at a rate of 15 an hour.

After seven years development work with a pilot machine, the Build- ing Research Station near London is now operating the first 5,000-ton press. The process and plant manufac- ture is now being undertaken by a con- sortium of British companies, Go-Con

Concrete Ltd., 17 Woodstock Street, London, W.1.

The commercial Gon-Con press has been designed to produce concrete components ranging in size up to 20 ft. (6 metres) long and 9 ft. (2.7 metres) wide with a maximum thick- ness of 10 in. (254 mm).

In addition to their use in apart-

ments and houses, the panels will be suitable for a wide variety of engineer- ing projects and the process represents a 300 per cent improvement on output for capital invested compared with existing production methods, say the developers.

The average cost of a complete Go-Con plant is expected to be in the region of £500,000, but users will be contracted to pay Go-Con a royalty on panels produced. Sales discussions have already begun with 60 organisa- tions in more than 15 countries, in- cluding Japan.

INSULATED ROOF

A new system of insulated roofing has been developed by an Australian company, heatshield Research & Deve- lopment Pty. Ltd., and is being manufactured under licence by Central Queensland Roofing Pty. Ltd.

It is called Monak Heatshield and consists of corrugated sheets of high tensile galvanised steel, clear polythene and highly reflective aluminium foil, all permanently heat bonded together.

Monak Heatshield roof

The main heat-shielding effect comes from the aluminium foil under- surface of the roof unit. This prevents the downward transfer of heat by ra- diation. The roofing is protected from the oxidation process which normally takes place on the underside of galva- nised roofing and the polythene is pro- tected from deterioration by ultra- violet radiation and acts as an effective barrier against electrolytic radiation.

The overall thickness of Monak Heatshielding is 0.2 in., and the weight is 96 lb. per sq. ft.

45