Introduction: Workshop technology

Types of hammers-

Types of chisels-

Types of screw drivers-

Types of files-

Types of punches-

Bench vice-

these are work holding devices which are mounted onto the tops of work benches.

They are used to hold work pieces whilst carrying out operations like filling, sawing, bending etc.

Hacksaws-

these are used to cut bars, rods, sections, pipes, conducts, tubes, and cables etc.

Types of pliers-

Types of spanners-

Types of Taps-

[these are used to make internal threads.]

Types of Die-

[these are used to make external threads]

Types of reamers-

used for enlarging and finishing to accurate dimensions holes that have been drilled, bored, or cored. A reamer cannot be used to originate a hole.

Screw extractors-

watch video for better understanding – https://www.youtube.com/watch?v=Hl7WT7TbhrE

Vernier calliper-

Micrometre-

Feeler gauge-

used to measure clearances between the two surfaces.

Bearing puller-

it is a tool which is used to remove components such as bearings, gears and pulleys from a shaft 

Drills bits –

Inside and outside calliper-

used to measure inside and outside diameter.

Tri square-

it is a tool used for marking and checking 90° angles on pieces of wood

Chain block-

Paints-

• The purpose of painting is to provide steel, iron or wood an airtight coating to prevent them from rusting, rotting or corroding.

• It creates a barrier between the metal and the environment.

• Firstly, we ensure that the surface is completely clean. This involves removing any elements or previous products – including paint, if it is not in good condition – and eliminating any organisms that may have attached themselves to the hull.

• The aim of all this is to ensure a perfect finish, allowing the vessel’s paint to remain in good condition for much longer.

• Primer serves as a base for all subsequent layers of paint, preventing sea water from damaging the surface. 

• Thinners reduce the consistency of paints to the proper degree for application by spraying or brushing.

    They also increase the penetration of the

     paint into the surface and reduce gloss.

Types of paints-

Type of paint	Properties	Areas of use on ship
Alkyd paints	It Consists of polymers, which easily binds-up and form coating	Superstructures, internal decks and bulkheads.
Bituminous paints	it forms the coating that provides weatherproofing and corrosion resistance to the elements	Suitable especially for chain lockers
Chlorinated paints	It provides excellent chemical resistance and durable with salt and fresh water	Suitable for decks and ship side
Vinyl paints	It provides corrosion protection and abrasion resistance at high temperatures.	Suitable for boilers, main and auxiliary engines
Epoxy paints	These are durable paints, which provides glossy finish to the elements.	Used for surface protection.
Polyurethane paints	Also known as PU coating it is highly durable and chemical resistant	Suitable for cargo tank coatings on chemical tankers.
Anti-fouling paints	It has the ability to keep algae & weeds away which loves to grow on ships outer hull	Used for coating on ships hull in dry docks.

Precautions taken care off during painting-

• Wipe off all the dirt, grease and oil with cotton rags.

• Use of kerosene or the degreaser to remove any oily stains & wash off the same with fresh water.

• Remove all rust and scale.

• If cloth becomes soak with paint, remove it and soak with soap and water.

• If eyes are splashed with paints, rinse off immediately with fresh water for 15 min.

• Paints and thinners must be properly secured in pain locker.

• Rags, cotton waste should be stored properly in order to avoid spontaneous combustion.

• Paint drums must always be closed to avoid evaporation of solvent.

• Avoid inhalation of paint fumes.

• In case of fire in paint room use DCP type extinguisher the fire.

• Paint should not be removed from electrical fittings.

Procedures for using tools for surface preparation-

• Wear PPE.

• On tankers while working on weather deck use only brass chipping hammers.

• Remove all the dust and wire brush the surface after brooming the area well.

• Clean the surface with fresh water and air hose it, for better cleaning.

• Never leave the cleaned surface without using a primer.

• For larger surfaces power tools has to be used with proper safety measures.

• Be cautious while using chipping hammer to avoid any accidents.

Types of paint brushes-

During bunkering-

• During start of the bunkering the pumping rate is kept low.

• After confirmation that oil is filling in the correct tank the pumping rate is increased.

• Filling of tanks has to be done, one at a time.

• The maximum allowable tank to be filled is 90%.

• Frequent sounding has to be taken; frequency should be increased when the tank is nearly approaching the desired quantity.

• Bunker tank temperature should be checked to avoid any short fall of bunkers.

After bunkering-

• Draught and trim of the vessel should be checked.

• Take sounding of all the tanks bunkered.

• The vol. bunkered should be corrected by trim of the vessel.

• Four samples should be taken.

• Chief engineer signs the bunker delivery note.

Working condition while doing painting-

• Painting should not be attempted at a temperature below 32-degree Fahrenheit because in cold weather, moisture condenses on surface and the paint will not stick. The thinner will also evaporate too slowly, increasing the drying time.

• For best results paint between 60oF to 80oF. In hotter weather, paint dries too rapidly and makes brushing & rolling difficult.

• Humidity and ventilations are also taken into consideration. High humidity may cause condensation on the bulkheads makes painting difficult, to tackle this out reduce humidity by ventilation.

• Proper ventilation is mandatory to carry off solvents and to furnish oxygen so that the paint will dry properly.

Spray painting-

• It is speedy method of painting large surfaces. The coating material is atomized by a stream of compressed air and is propelled to the surface by the air pressure.

• Disadvantages are high loss of paint due to over spraying and thinning down of coating to get the jet of spray.

• The spray gun should be kept clean after use so that the paint does not dry inside the gun and clough the system.

• Airless spray is more effective method of paint application. The coating is diffused by being forced through a small opening where the drastic change in pressure atomizes the paint and propels it to the surface at a powerful rate. It reduces overspray and gives better coating.

Classes of spray gun-

External mix spray gun-

• The air and paint are mixed outside.

• This type of gun requires high air pressure, thereby using more air per minute.

• The atomization is very fine and size of the spray pattern can be controlled.

• There is no wear in the air nozzle.

Internal mixing spray gun- 

• Air and paint are mixed in the gun.

• In this type of gun, atomization of the paint is coarse and spray pattern is fixed.

• This gun works only with the pressure feed, but pressure is lower and less amount of air is used.

• Because of coarse atomization more paint is applied on each pass.

Operation of spray gun-

• Pressing the trigger of the gun opens the air valve, admitting air into the inlet.

• Before spraying of paint, it is important to check adjustment and operation of gun by testing on the similar surface.

• The distance between the gun and the surface should not me less than 6 to 10 inches.

• Always keep the gun perpendicular to and at same distance from the surface being painted.

• Start the stroke before pressing the trigger and release the trigger before finishing the stroke, thus failing to do this will cause the paint to run or sag.

• If the gun is not perpendicular or held too far the paint will evaporate and strike the surface in dry state.

• In large areas with small parts and pieces protrude is being painted, first lightly coat those items, then start painting. This eliminates a lot of touch ups later.

Care of spray gun-

• Clean the equipment after sue.

• Release the pressure from the pressure tank by means of release valve.

• Hold a cloth cover over the air cap and pull the trigger, this forces the spray material back to the tank.

• Remove fluid/paint hose form the gun and run solvent through the hose.

• Dry out the tip and clean the tank. 

Respirators-

• Spray painting breaks up paints 

Hand transmitted vibration-

• it is anmechical vibration caused by powered devices or tools that enters the body through the fingers or palm of the hands.
  
  Hand-transmitted vibration is also known as hand-arm vibration and local or segmental vibration.
  
  It affects the sensation of fingers and hinders the blood circulation.

Important power tools-

Needle Gun-

• This is a device that consists of a piston stuck by a group of needles.

• The needle gun is operated by air, such that the needle strikes the surface individually.

• The needles will have to be renewed when they are worn out and based upon the requirements the size of the needle should be selected.

Pneumatic wire brush-

 After chipping the next step is to wire brush the surface which is achieved by pneumatic wire brush. The attachment has to be removed after the wire brush is worn out.

Electrical hand grinder-

• Important component of an electric grinder is the motor.  the motor is in charge of all the power and movement of your angle grinder. Angle grinder motors have different power ratings depending on the type, quality, and price.

• Side handles on grinders allow users a two-handed grip, which increases control and stability.

• Angle grinders are commonly used for polishing concretepreparing metal and concrete surfaces, bevelling , stone, and metal, grinding welds, cutting tools and material edges, cutting metal plates and pipe, and grinding welds.