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Friday, June 28, 2013

DIY Mosquito Screens

28 June 2013

Introduction 


Dengue is the  name of a disease spread by a special mosquito called aedes mosquito. 

To date,   It has claimed 4 lives in Singapore.  It is also a common disease in Philippines,  Malaysia and other countries in South East Asia.  So far,  there is no cure or drugs for treating dengue;  doctors will just prescribe pain killers and make observation for life threatening signs. This article will describe the experience that the author has had fighting against Dengue.


How To Prevent? 


The only way is to avoid a mosquito bite but it is easily said than done as mosquito is everywhere.  The common knowledge is to eradicate the mosquito breeding grounds.  NEA (National Environment Agency) found 80% of breeding grounds are actually right at home.  This however does not prevent one from mosquito bites because there are so many breeding grounds out there in the natural habitat that cannot be easily eradicated. 

The only effective way the author has found is to install mosquito screens at home and wear repellents outdoors to prevent contacts with the mosquito.  The article will concentrate on how to install these mosquito screens DIY and save money. 

Why the Screen?

1.  It is a permanent measure that will save "tons" of insecticides which is not only  harmful the environment but also the human beings;

2.  It cost next to nothing to maintain;  only occasional cleaning is required;

3.  It does not block out much sunlight and ventilation;

4.  It is aesthetically pleasing as screens are almost transparent;

5.  One can repair the screen easily using thread and needle


How Many Type of Mosquito Screens? 


There are many types of mosquito screens available in the market;   roughly,  they fall into 2 categories; the fixed and the removable type. 


The fixed type can often be done as simple as using construction plastic coated green mesh or net available from many local hardware shops;  the more sophisticated one will use special woven net materials.  They come in a roll form.  Some plastic coated green mesh can be quite brittle and are not suitable for screen making because they will tear easily during installation;  the better ones are woven type.  They all look about the same but the woven ones are thinner and has fibre threads.








The removable ones are mainly of woven net materials except it is first fixed onto a specially made PVC trunking and then attached to plastic magnets so that they can be removed at will for cleaning for example.  As there is a video made for the removable type,  this article will concentrate on how to install the fixed type.

How to DIY using Construction Mesh/Net?


To install the wire mesh onto the wooden window frames,  one can use small timber strips and a staple gun. 



Cut a piece of mesh slightly bigger than the opening and fix into position with timber strips; thereafter staple the timber strips onto the window frame with the staple gun. Making sure that the timber strip is thick enough to fit the staples to let it stapled onto the wooden frame.


To install the wire mesh to metal frames or concrete wall would require having to fix first and screw a small timber frame onto the metal frames or concrete using electric drill and fixing screws.  After that,  one can use the same method as fixing the mesh to the timber frame as described earlier.

How to DIY using Woven screens

These woven screen comes either with honey cone or square net form. 


They are stretchable and can be hooked onto velcro strip that usually come as a package as shown.  They will cost around USD$2/= from ebay suppliers directly delivered to your door steps.






The fixing is relatively simple and quick.  The velcro is first fixed onto wooden or metal frame work after having first cleaned the surfaces with industrial thinner or equivalent;  thereafter,  just lay the screen over without stretching and press the screen onto the hook of the velcro.


The trick for successful installation is NOT to stretch the screen when laying it over the opening.  Stretching the screen will cause undue pulling force on the velcro which can become detached easily,  leaving a hole;  then the only way to re-fix the velcro in position is to staple it using the staple gun.



Mosquito Screen for Sliding Windows


Most of the windows today are sliding type.  There are 2 ways to fix mosquito nets.  One is to fix it external either directly onto the window grilles or metal mesh or to construct a wooden frame as big as a window panel.  Fix the screen first onto the timber frame using the same methods described above then mount the screen as if it is one of the windows.


Sliding Screens for Doors


The screen for the door will be a bit harder to construct because it will involve a sliding type of screen. However,  one can construct the screen door cheaply using an aluminium or timber frame to slide it along a window curtain rail as shown. 




Allow horizontal and vertical adjustment in the brackets holding the curtain rail to get a smooth sliding.  There will be a need to install a pvc strips on the floor next to the screen door as a stopper to prevent screen door from swinging in and out or to and fro when the wind blows.

The curtain rail is easily available from any hardware store.  A sliding screen door can be made within a day or two for less than SGD$30/= ( $ 15/= for the aluminium frame,  $ 10/= for the curtain rail and $5/= for the screen and the angle brackets or stiffeners.)   If aluminium frame is used,  just glue the screen onto the aluminium frame and trim the edges after having the ugly glue parts concealed by using special timber strip of 5 to 10 mm width (from Diaso IMM store or Art's Friends at Bouna Vista MRT station).   

There are also special curtains made for the door and they are available for ebay.  The curtains have  magnetic strips on the opening edges to seal the curtains.

.

 Q & A

 

1. Will the screens cut out natural lights and ventilation?

The mesh or net will cut not much lights and ventilation. The normal construction green mesh may cut by less than 10%;  the woven screen,  by less than 5%. The woven screen is almost transparent viewing from a distant of more than 2 feet away.  




 2. Wouldn't mosquito still get in through the doors?


Mosquito will like to rest on dark surfaces,  especially when the doors are colored dark. When one opens the door,  it is very likely for mosquito to be "blown" into the house by the "wind" of the door.  One way to prevent this is to have light colored doors;  the alternative is to place mosquito repellents near the door way and renew the repellents every now and then when they expire. 

3. Would the screens trap dust?

Yes.  Some dust will accumulate over time but vacuum cleaning will keep them clean again.

4.  I bought the woven type with velcro from ebay.  How do I hide the ugly edges?

The screens come with a 5 mm velcro strip which can be an eye sore when the screen's edges are untidy.  One good way to hide the ugly edges is to cut another velcro strip and press it onto the original velcro;  the alternative is to buy small 20 mm x 10 mm or smaller trunkings meant for electrical wiring to cover up the edges.  Fortunately,  only the windows at the corridor are exposed and need the edges to be covered up.


5.  Must we ensure that all openings are protected? Some are difficult

All openings in the house must be protected,  even the openings leading to open yards and door ways.  It will be useless to protect all windows and leave the doors open.  Install door closing device if needed be to ensure the doors will be closed at all time and also double quick.  There will always be a way to seal the openings.  Discuss this over with your carpenter or home builder

6.  Why do we need stiffeners for the sliding door screen?

The sliding door made from 12 mm square aluminium box section will be very unstable for a screen door of about 2.2 metre tall and 1.5 metre wide.   Stiffeners and angle plates plus cross bars will need to be added to ensure the screen door would not wobble.

7.  How to Prevent Sliding Door Screen from Swinging?

The sliding door screens made from aluminum frame are quite light and will swing if there are strong wind.   To hold down the frame,  one would need a floor track for the door.  The author used a long piece of 3/4" width telephone trunking as the floor track and 2 Nos of 5 mm stainless steel ball bearings as door slider at each end of the door screen as shown


Cut 2 short piece of aluminum channels and drill 2 holes on each piece.  The hole shall be made just slightly smaller than the diameter of the ball so that it will hold the ball in between the channel and the door frame.  After ensuring the ball bearing is free to move,  fit the aluminum channels and ball bearing to the screen frame using rivets.  (Tip: One can start drilling the hole one size smaller than ball diameter and use hole reamer tool or round needle file to enlarge the hole)


Monday, June 24, 2013

Monitoring Haze

24 June 2013
 

Introduction

Haze is here to stay as long as there are plantations in Sumatra of  Indonesia where fire is often used to clear the lands for agricultural purposes.   The haze will linger over Singaporein the middle of the year until October or November when North West Monsoon begins to blow from North towards Sumatra.

Is Haze Dangerous?


Haze is harmful to human's respiration system;  prolonged inhaling of haze particles will cause sickness and those with acute respiration or heart problems  may find it life threatening.  During the hazy days with PSI (Air Pollution Index) going above 100,  many will have to cancel outdoor activities and will be advised to stay indoors or wear N95 face masks outdoors.   

How to Monitor?

 
Using particle counters that can measure air particulates as small as 2.5 micron in diameters;  however, these counters involves laser technology and they are not cheap.  A cheap one will cost around SGD$300-400 and professional ones may be as high as SGD$30,000/=.  These counters are out of reach of most households.  Fortunately,  Singapore's NEA (National Environmental Agency) and Malaysia's DOE (Department of Environment) maintain websites during the period where one could get latest readings of the pollution indexes. The Singapore website provides 3 hourly as well as 24 hour readings whereas the Malaysian website updates the data once every 4 hours. 

The Singapore's NEA website can be found here.

The Malaysia's DOE website is here 
(Note:  this website is always in heavy usage;  accessible easily off peak)

How About Forecasting? 


The Singapore's NEA provides daily forecast in its website and the forecast is updated once a day.  However,  the forecasts are not often accurate for some reasons;  for example,  NEA forecasted that the PSI  will reach 300  on 23 Jun 2013 whereas the day's actual  maximum was around 110 and staying below 100 most of the day.
 
 

How Can We Confirm the Forecast?


Fortunately,  there are very comprehensive free weather forecasting website available for Singapore;  they are:-
 



One can use their wind direction predictions together with the regional haze map  to check and confirm the forecast.

How?


One will need the following tools:- 

a)  A regional haze map showing the geographicallocation of the haze(free from NEA);  for example
  

b)  The prediction of the wind directions given by the 3 free weather sites;  for example,

 

First check the haze map.  If Singapore is not in or near the haze cloud as is shown in the above haze map,  Singapore is likely to be free from haze for the day. This should be further confirmed by the wind directions. If the wind direction is not pointing East or North East  and is pointing North or North West like being shown,   most likely one would enjoy pollution free sky in Singapore and vice versa.

 

Planning for a Trip to Malaysia? 


Many planned to hide from the haze and go to Genting Highland for holidays;  some went to Penang. Is it safe?

The Regional Haze Map,  the DOE and wind direction predictions will show that it is not advisable to head to Kuala Lumpur,  Genting,  Pahang,  Muar or Melaka at the present moment.  The haze cloud and the wind directions are heading North and North West.  Penangat present is free from pollution but will soon be clouded with haze if the prevailing North West wind is strong.

Planning to Go Out?

One could check the sky condition and also the webcam picture from the following sites for conditions of the haze. 

a)  Webcam @ Admiralty Road

b)  Webcam @ Kent-Ridge

c)  Webcam @ Raffles Place





Thursday, June 20, 2013

How To Conceal Car Camera Wirings

20 June 2013
 

Introduction


Car camera is a plenty nowadays in the market.  They are cheap around SGD$50/=. It has quick to become an essential piece of equipment but unfortunately,  the camera must be retrofitted as it is a non-standard item for most cars.

What are the Installation Problems?


One problem is how to conceal the "long and black" cable that is getting electricity supply from the cigarette lighter.  Many have run the cable exposed as shown which is quite unsightly.
 
 

How to Conceal?


Fortunately,  most cars today are fitted with loose panels and ceiling board so that they can be easily removed or interiors accessed without having to tear them down.  This article will use 2011 Toyota Yaris Spirit as an example to illustrate how the wiring can be concealed.

 

Step by Step


1.  First,  remove the windscreen side panel

 

The side panel is held in place by two bottom clip and special clip on top as shown
 
 
To remove,  first use finger to pry open the side panel at the top to expose the special clip.
 
 
 
Then twist the base of the special clip so that the hook is in-lined with the slot of the side panel for the panel to be pulled out sideway. 
 

 
 
Remove the side panel, paying special attention not to damage the air bag assembly for the side windows
 
 

2.  Remove the instrument subcover

 
Remove the 2 screws and pull the cover down to release the 2 catch as shown.  This will expose the interior parts above the clutch and the brake panel
 

3. Thread wires through opening

 
Thread the wire through the opening as shown below.  Note that the author has a specially made cable and a box to house other electronics;  otherwise,  the stock cable can just be run through here to the cigarette lighter without mounting the box.
 
 

4.  Fixing wire to instrument sub cover

 
 The cable can be run across the instrument sub cover and fix in position by bluetac as shown. 
 
 

5. Running cable along the roof

 
The cable that run across the roof and can be hide inside the roof by prying open the edge of the ceiling board using just fingers. 
 

6.  Assembly back components

 
Reverse the dismantling process to reinstate all components back to their original position
 

7.  Completed Wiring

 
The completed wiring installation is as shown below.
 
 
 
 
 
 
 
 
 
 

DIY Air Filtering Face Mask

20 June 2013

Introduction

When the PSI reading goes above 200,  it will be good to wear a face mask even at home unless one has a proper and efficient air filtering system in the room. What happen if you and the stores run out of face mask?  It is happening now in Singapore.

DIY a Face Mask


For ladies,  they could have used their  bra but for most,  it is better to find other materials.  One of them is the non woven electrostatic fibre paper that has been used extensively for  floor cleaning. Tissue paper can be alternative source but they are too fragile to handle.






Whats Needed? 


1.                  A box of electrostatic fibre paper easily available from any convenience store @ SGD$1/=

2.                  Four rubber bands

How to Construct?


Take one sheet of fibre paper and fold it in halve.  Tie two rubber band together in a link and tie the rubber to the end of the paper.  Wear it with one end of the rubber band to the ear.

If needed be,  insert a trash bag tie and staple it to the top of the mask for closing up the gap between the paper and the nose.. 


Adjust the length of the rubber band to suit comfort wearing..  If one layer of paper is not sufficient,  use 2 layers.

Disclaimers:  These are not proper substitute for commercial face mask.  The method is untested.  It is intended only for emergency use when one runs of face mask in the stores.

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