2011년 11월 21일 월요일

Boat Construction (7)

   While I was working on the inside hull, half of my class were working for a deck. I did not join in them directly,but I helped them sometimes and saw the processing. It follows same way of composite in 'F.R.P' course.  
In brief, on the moudle we waxed five times and polished with cheese clothes as well. Then we coated 'PVA' slightly.  After it dried, we put ' boat coat' and 'double bias' with expoxy resin. Put form on the glasses with microballoon gap filler and pressed them with vaccum bags.The method is that by sucking the air in the bag so odjects are keeping stuck together. In invers order, put double bias and boat coat on that. Last, put 'Low density fairing filler' on the top, because it is able to do sanding and painting easily. Once finish this procedure, it could be demoulding and join to hull.









2011년 11월 17일 목요일

Boat Construction (6)

For finising I needed to do coving. It is commonly used for making strong and tidy joint. However, it was much harder than my expectation. To obtain nice clean cove-shape,I firstly vaccumed the area and  prepared  a plastic rounded filleting tool, box of Aceton, a putty knife and rags. Once I make a glue with





2011년 11월 11일 금요일

Half model3

 There were gaps between the plug and the backing board, soI filled the gaps using a putty. Then, I must ensure that the surface of plug is very clean.



After that I did waxing on the surface. It helps to come off from the matrix which I will finally make. Normally, we need to do waxing around four times to six times. (I did six times for my half model) Also, we need to wait awhile for drying before spreading next wax. Actually, there were two kinds of wax in our workshop. 'TR 108 Basic Mould Release Wax' is that I used for coating my plug. 'Honey wax' is another one http://www.specialtyproductsco.com/specialty/Paste-Wax/Honey-Wax%C2%AE/flypage.tpl.html.
Two of other students who used honey wax, did not use PVA film liquid. It has a silicon additive so it prevents PVA

We have to make one more layer with  PVA (Polyvinyl acetate). I put the PVA liquid thinly with an edge of sponge. It needs 30minutes to an hour to dry. 

   The next step was gel coating.  For progressing this job, we need M.E.K.P as a hardener. The ratio of M.E.K.P to resin is between 1.5 to 2%. I used 700g of gel coat and I put 11ml (approximately 1.5%) of MEKP.

   Once mix these two liquids, we should start working immediately. It does not take long time to be solid.

   With an air brush, spay on the surface gently. Put sufficient amount of gel coat (between 0.75 to 0.5mm) especially the edge part because it might be cracked during the demolding proceesing.

I waited around three more hours for letting then dry.

The final stage was making the matrix with 'fiber stitchted rovings' and 'chopped strand mats'. I prepared 500g of Polyester and 2% of M.E.K.P (10ml). My group and I had to work quickly because the resin also becomes hard in a little while. At the first, filled all of edge part with fiber stitched rovings to make a clean out line. Then tore the chopped strand mats and pasted them onto the plug. Once the chopped strand mat is wetted by Plyester, it becomes limp. With a brush, sticked them nicely and get rid of all air bump with a compression roller. 




2011년 11월 8일 화요일

Half model 2

 Unfortunately,  my timber has pine resin, knots.  In addition, the bow part has some flaws so I needed to fix it. Actual process is coating the epoxy resin on the plug, however my half model had some scars, so I used another processing. My tutor suggested me to use "Dura tec" instead of epoxy resin for coating my plug.  It can cover all of bump surface of my half model and it is easy to do sanding.


       For using 'Dura tec' , we need a catalyst as well. M.E.K.P (Methyl Ethyl Ketone Peroxide)  is common catalyst with polyester resin. Normally, put 2~3 precents of primer's weight, so I used 1370 g of 'Dura tec' and added 30ml of  M.E.K.P
Primer (Dura tech) + 3% of Catalyst (M.E.K.P)

1370  + 30(M.E.K.P)




I used an air brush for coating 'Dura tec'. One of important thing when we work in F.R.P is wearing safety equipments. The materials are flammable and poisonous. It would really harmful for human body. That's why we have to ware safety equipment and must know how to deal with when emergency happened.



To fill the gaps, I brushed thickly. After drying Dura tec,  my group and I sanded the surface of the plug until all of scratch disappearing. 




Half model

I had a 7.3m yocht half breadth plan for making a half model plug.  


Cutting list


?? x 120 x 20(mm) radiata pine tree 



I put the plan on the pine timber and punched along the line. After that I cut them off along the dots with a band saw.There are nine timbers that I overlapped and between timbers become 'water lines'. Therefore, there are eight water lines. I put a thin dark colour timber between 3rd and 4th timber and it is 'load water line'.  

I made two dowel holes to put togerther easily. 
After gluing them together I shaved the model with a block plane and a spoke shave.
My group members made keel and rudder as well. The front point of the keel is positioned at station 7. The rudder is positioned on the transom

Size

Keel (pine)

Top - 88.7 left - 105.3 bottom - 61.3 right side 88.6 thickness - 5.4

Rudder(pine)

170 x 50 x 5   

2011년 10월 19일 수요일

Health & safety

- OBLIGATION-


1. Employer



An employer is the person who employs any person to do work.
They have to provide and keep a saftey working environment.  Also, They need to provide and arrange facilities for the health and saftey of their employees such as first-aid things, personal protect equipment and emergency equipment. The employer should consider employees' physical stress and psycho-social stress as well.  In addition, as an employer, they have to develop procedures for dealing with emergencies that may happen while employees are working.
Hazard management responsibilities
The employer have to manage significant hazard at the workshop.
firstly, they need to know the identity of machinary and meterials, so the employer can foresee and deal with portential danger in advance. Moreover, they should evaluate the harm of their facilities. Follwing these, the employer have to controll and mornitor not only employee but all of the equipments.
These controls generally eliminate, isolate, or minimise hazards in a more reliable manner than personal protective equipment.
Furthermore, the employer should know what employees need such as  personal safety gears. If nessecery, they should inform and train about hazard and safety their employees. The employee must be adequately trained in the safe use of all plant, objects, substances, protective clothing and equipment that they are or may be required to use or handle. For the reason, the employer have to supervise all of stuff. Whenever receives an injury report from an employee, an employer must document the incident


2. Employee

An employee is any person who is employed to do any work for hire and reward under a contract of service. They have keep the health and saftey by them selves. Can not act which may harm others while on duty. They need to report to manager or suoervisor when they find any hazard or any machinary troubles. Also, they must not misuse or break any equipment. They should have oppertunities for improving thier health and saftey knowledges. They also, have the right to refuse to work if the work condition is not safety enough. When employer explain about hazard on work to employees, they must show that they understand it.
All employees, even contracted or temporary workers, should receive training in workplace safety on the first day of the job.

The requirement to instruct employees in the use of protective equipment should be read in conjunction with that of which requires that employers are advised of the hazards they may experience in their work, and the steps needed to overcome them
 Employees should know what steps to take in the event of workplace injury, equipment malfunction, fire, natural disaster or other incident. Periodically run through the emergency plan so that workers understand evacuation routes and assigned responsibilities when crisis strikes.

3. Designers, manufacturers and suppliers of plant to places of work. They require designers, manufacturers, and suppliers to give employers the information they need to fulfil this duty.

 
Employees should know what steps to take in the event of workplace injury, equipment malfunction, fire, natural disaster or other incident. Periodically run through the emergency plan so that workers understand evacuation routes and assigned responsibilities when crisis strikes.




-PERSONAL SAFETY APPAREL

Personal protective equipment (PPE)  are including clothing, hard hat, goggles and, boots which are designed to protect the wearer's body from injury  by blunt impacts, electrical hazards, heat, chemicals, and infection, for job-related health and safety purposes.  The use of personal protective equipment is to reduce employee exposure to hazards while on duty.

A steel-toe boot (also known as a safety boot, steel-capped boot or safety shoe) is a durable boot that has a protective reinforcement in the toe which protects the foot from falling objects or compression.

Ear defenders protect the wearer from extreme noises. The head band and outer covering is usually made from a hard thermoplastic or metal.
A hard hat is a type of helmet predominantly used in workplace environments, such as construction sites, to protect the head from injury by falling objects, impact with other objects, debris, bad weather and electric shock. Inside the helmet is a suspension that spreads the helmet's weight over the top of the head. It also provides a space of approximately 30 mm (1.2 inch) between the helmet's shell and the wearer's head so that if an object strikes the shell, the impact is less likely to be transmitted directly to the skull.

A respirator is a device that designed to protect the wearer from inhaling harmful
dusts, fumes, vapors, and/or gases. Respirators come in a wide range of types and sizes used by the military, private industry, and the public. Respirators range from cheaper, single-use, disposable masks to reusable models with replaceable cartridges.
There are two main categories: the air-purifying respirator, which forces contaminated air through a filtering element, and the air-supplied respirator, in which an alternate supply of fresh air is delivered. Within each category, different techniques are employed to reduce or eliminate noxious airborne contents.
 




Heights


Always wearing PPE and fall aresst devices while on duty
Be aware what kind mishap may happen and concentrate on own job
Worker must eliminate any dangerous or risk equipment.
Put equipments on the right place
Use a aldder on the flat ground






Confined space

When it comes to working in confined spaces, the management must make provision to identify any hazards present, assess the risks posed by them and put procedures in place and take any necessary precautionary measures to protect the workforce. All of these considerations will usually be determined by the following

  • What the work entails
  • The environment in which it is carried out
  • The materials and tools that are to be used
  • The competency and suitability of those employed to carry out the work
  • Emergency rescue or evacuation procedures
  If the results of the Risk Assessment identify any possibility of serious injury or stress from working in the confined space then the Confined Spaces Regulations apply.

  The Confined Spaces Regulations cover a broad range of industries and how the legislation might apply to a particular location which has been deemed to be a confined space. However, in brief, management firstly needs to check if the work that’s involved could be carried out without the need to enter the confined space. Obviously, that isn’t always possible so the next step is to develop and manage a safe system of working practice which all people who are entering the confined space must adhere to. Each and every worker’s life could be at stake so everybody must be fully instructed and trained to ensure each of them know what their responsibilities are, the tasks they need to carry out and how to carry them out safely in accordance with the legislation.


Underground


Employees exposed to public vehicular traffic shall be provided with, and must wear, warning vests or other suitable garments marked with or made of reflectorized or high visibility material. Employees are not allowed under loads handled by lifting or digging equipment. Employees must stand away from vehicles being loaded or unloaded to avoid being struck by spillage or falling materials. Operators may remain in the cabs of vehicles being loaded or unloaded when the vehicles are equipped to provide adequate protection for the operator during these operations.


The compliance requirements for people worinking in range of location

 
Using power tool

1.Do not use unless you have been trained
2.Do not use in the area where may explose
3.Do not suprise or touch the person who is operating the tool.
4.Ask to hold or use clamp the object
5. Check the switch and controller before use it. 
6. Keep clean the work space and the tool.
7. Be sure to keep good position and good balace when you are operating.
8. Do not remove the guard

 
Using machime

1. Be aware where the emergency stop button is positioned.
2. Waring PPE if it is necessary.
3.Do not misues it
4.Report if the machine has any demeges.
5. Do not rush.
6. Give the motor time to reach full speed before it is put under load, otherwise the motor burn out

Using pneumatic devices.

1. Eye and head protection gears are required.
2. Do not point at anyone.
3. Ware hearing protection


Responsibilities of employer and employee to manage workplace hazards.


The strategy for dealing with these risks is to use the 5 point process

IDENTIFY Existing, new, or potential hazards.
ELIMINATE. Get rid of the hazard e.g. use flash proof lights.
ISOLATE. Confine the hazard to a certain area if elimination is not possible. E.g.       Dangerous goods store.
MINIMISE. Keep the hazard to a minimum. E.g. good ventilation
MONITOR In a planed ongoing manner keep record of all of the above points.




reference 

 http://www.wikipedia.org/ 


2011년 10월 1일 토요일

Boat Construction (5)

The water tank will be installed underneath  the berth and water pipes are going to go through under the toilet and basin. These are turned under the cockpit and go to galley. To lay pipes I  broke a way. I cut base of basin and made a hole on blukhead between the plinth and  the berth. 




As a next step, I had an oval basin bowl and cut a hole on the top of basin.  Firstly, I put the bowl upside down on the top of timber and drew a line along the shape. By changing the plinth design the position of basin was rotated more.


Boat Construction (4)

I made doublers for fitting in the basin and set it up on the right palce. Plus, I made a basin cover too.

Over the my basin side of bulkhead, the cockpit is placed, and underneath of that water pipes are going to  be installed. That's why I made two holes and create smaller room for electic wirings.


Additionally, I built one more shelf insde the basin to gain enough storage.  
During the job, I made a mistake that I sanded the edges too much. It became too small to fit.  As a result, I had to make the basin shelf again which would be bigger than mistake one. To making right size of shelf quickly, I used a transfer skill that is measuring outfit with a small stick and transfer to other timber.


1. Check how much need to extend.
    Prepare a small stick.
2. Put down the stick on the timber and make sure its end touches the wall. Draw the outline of the stick.
3. Draw several more out line of the stick in same procedure  along the outshape.
4. Lay the timber down onto new timber which is going to transfer. Put the stick on following out lines. Mark the edge of stick. Link all these marks.

I made doublers along the bulkhead and small room. I also attached short doublers on the hull and inside the basin.