SPRAY SHOP

Spraying Equipment 2

2008-12-05T21:54:00.000-08:00

Material Container

The spray Gun can be fedwith material either by gravity, suction or by pressure. The three types, suction and pressure are most widely used, and will be described and illustrated, but a brief of description of the gravity feed gun will also included.

Gravity Feed Cup

This type of gun and cup is usually used for small task whad do not need a lot of material for stenciling. The cup is attached by a screwed thread directly above the gun with contain half pint of material in the small cup or one pint of the large cup.

With gravity feed a small amount of material is held in a cup with is situated above the barrel of the gun. The material is feed by gravity into the fluid passages of the gun is then ejected by the high velocity air jet in an atomized state.

Suction Cup

When a suction cup is used it is a attached by a 3/8 inch BSP screwed connection forward of the gun trigger. A cup consist of a container which hold up to a quart of fluid, a material feed tube, a gun connection union, and a lid assembly which incorporates a clamping device for securing it to the container. A vent in the lid of the container allows air to enter the cup and compensate for material as it is used.

When suction feed is useda small supply of materials is held in a cup which is located below the barrel of the gun. From this point, the material is drawn into the fluid passages of the spray gun through a feed tube which is immersed in the material. In this a partial vacuum is formed by the passage of air at high velocity around the spray gun nozzle tip.

Pressure Ports

The pressure ports used in the service usually of 2 gallon capacity. It consists of an outer pressure tank made of heavy galvanized steel, a material container of lighter gauge, steel and a lid assembly. The lid of the pressure pot incorporates the air connection, the fluid connection, a material agitator , a safety bar, a pressure gauge, a pressure relief bar and the material feed pipe. The lid fitted with O gasket it secure by screw clamps. The separator material container facilitas charging of the material. The agitator enables the operator to keet the material well mixed during the spraying operations. A flexible hose connects the compressed air supply source to a union on the lid. Some of the air passes via the pressure regulating valve to the pressure pot and the reminder goes along another hose to the spray gun. The pressure which is build up in the pressure pot forces the material from the container up through the material feed pipe line to the material inlet og the spray gun

SPRAYING EQUIPMENT

2008-12-04T00:11:00.000-08:00

Spraying Equipment

Introduction

There are severel difference designs of spraying equipment, but the functional principles are the same of each type used within the service. The components described and illustrated in the following paragraphs are representative of all at present in use.

Air Compressors

Before any of the previously mentined system can be used, is a necessary to have a continuous supply of air under compression. This is the obtained from one of two machine, ie. Mobile low pressure servicing trolley or a static air compressor, either of these will supply the nessary air pressure which is required for sparying purpose.

Air Transformer

This unit consists of a moisture separator and reduction valve, the moisture separator ensure that the air supply to the gun is clear and free from moisture and oil vapour. A moisture separator in the form of an air transformer so that impuritions and a drain cock is fitted at the bottom of the transformer so that the impurution can be drained away at frequent interval.

Is is again emphasized that the accumulated moisture which is trapped in the transformer must be drain off as frequenly an experience dictates otherwise the finished work will be spoilt. Where the electrical powered static type of compressor is installed the transformer are generally fitted at strategic point to the spray shop wall as an interval part of the spraying equipment. Spraying without the extra transformer will be quite satisfactory when humidity conditios normal

PAINT AND THEIR INGREDIENTS FOR AIRCRAFT SURFACE

2008-11-26T22:04:00.000-08:00

Introduction

The application of paint to metal surface is designed to give maximum surface protection, but with a minimum increase in weight. However servis aircreft now have attained very high speed and thus makes the adhesion of the paint, a major problem. therefore, the efficient application of this material is of prime important to the aircraft servicing.

Subsequently finishing scheme are devised to achieve the purpose;
a. To protect metal surface from corrosion
b. To weatherproof woodwn component, the only complete protection for wooden external finishes is a cellulose scheme inconporating a fabric layer.
c. To tauten and strenghten fabric c the fitted fabric overing. Airframe component cannot be covered in such a manner what fitted fabric will form a taut efficient skin. To over come this difficulty cellulose drop are applied which impregnate the fabric causing shrinkage and imparting increased strength and durability.
d. To provide camauflage. The important of this service aircraft is abvious. finishing material must be of a colour which will into the natural black ground againts which are aircraft will operate
e. To help identification. aircraft been insignia letters and number which denote nationality registration of service.
f. To reduce drag. Quite a lot of finishingprocess have been developed to provide an especially smooth surface to reduce the skin drag

Spray Shop and Healt Precautions

2008-11-25T17:10:00.000-08:00

In order to obtain the highest quality finishes, spraying must be carried out in a building, specially constructed for spraying job purposes, where the shop provides warm and dry atmosphere. It must be equipped with adequate lighting and free from dust. The temperature is controlled between 60-70 F and the relative humidity should not axcced 70%

Hazard

The material used in connection with spraying finishes often contain substances which are classified as very hamful to personal, if inhaled, ingested and handled without proper precaution.

a. Anesthetic
i. Gas, Vapour or fame which have sleep-producting and depressant effect on personal.
ii. Most of this belong to Hydrocarbon group eg. White spirit, petrol, napthene and carbon tetrachloride

b.Asphyxian
i. gas vapour or fume that prevent blood from absorbing oxygen from the lung.
ii. Eg. Carbon monoxide, epoxy and polyurathene

c.Irritant
i.gas, vapour or fume that cause irritation to eye, skin and respiratory system.
ii. Eg. Acetone, chromic acid, jet fuel and ammonia.

Note : Propper used of safety precaution such as using respiratior, special clothing, glove and barrier cream will minimize injuries to personal.

Spray painting

2008-11-23T03:48:00.000-08:00

Spray painting is used in a variety of industries and by a variety of workers. It is used to paint motor vehicles, buildings (inside and outside), structures, furniture, white goods, boats, ships, aircraft and machinery.
Spray painting is associated with a number of health and safety concerns, so employers and self employed people who conduct this activity must manage the risks in their workplaces.
In order to understand the workplace health and safety requirements for spray painting, and your obligations under the law you must consider and understand relevant legislation and codes of practice.
What law appliesLegal obligations, legislation, guidesHazardous substancesHazardous substances used in spray painting, MSDS, labelling, two pack paint and varnish systems
Plant and equipmentHow to use spray painting plant and equipment safely, spray painting booths, spray painting motor vehicles
Flammable hazardsTypes of flammable substances used in spray paining, preventing fire and explosion, heat stress, electrical safety
Other hazardsConfined spaces, noise, workplace environment, manual tasks