Case Study: The most appropriate Water Repellent Coating Product

for use and application on Radio Antenna Surface

(GX4000 Series Antenna)

Prepared by: Abd Hamid Bin Jimin

Date: 9 December 2015

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Table of Contents

Page

Table of Contents......................................................................................................... ii

1.0 TOPIC OF CASE STUDY...................................................................................1

2.0 AVAILABLE PRODUCTS IN THE MARKET ....................................................1

3.0 FEASIBILITY STUDIES ......................................................................................2

3.1 Hirec 1100 ............................................................................................................3

3.2 DryWired SHC .....................................................................................................4

3.3 Hydrobead ...........................................................................................................6

3.4 NeverWet OEM ...................................................................................................6

4.0 FINAL CRITERIA IN CHOOSING RIGHT WATER REPELLENT

PRODUCT .....................................................................................................................7

5.0 SPRAY-ON COATING PROCESS ....................................................................8

6.0 MAKE YOUR CHOICE .......................................................................................8

7.0 RECOMMENDED PRODUCT ...........................................................................9

8.0 CONCLUSION ................................................................................................... 10

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1.0 TOPIC OF CASE STUDY

The topic of case study was titled as “The most appropriate Water Repellent Coating

Product for use and application on Radio Antenna Surface (GX4000 Series Antenna)”.

What does water repellent means? The definition of water repellent is something that, when

it exposed to liquid (water from rainfall for an example), it reacts with the water to cause it to

move away instead of to be penetrated or soaked in.

There are water repellent watches, mobile phones and such where the casing and the

display are made of water repellent material or coated with a water repellent. However, there

is a limit to the extent the water can be repelled and the water repellent objects let water

come into the object making it wet after some time.

An example of water repellent is a handy aerosol-type coating that you can spray it on an

antenna surface to keep it from soaking in water and beginning to rot or warp during rainfall.

Based on the study done by radio antenna producer to Radio Frequency and Water Film

Attenuation on Radio Antenna, it gives the following results;

a) Water film attenuation increases with thicker water film and higher radio frequency.

b) Attenuation is over 5dB at water film thickness of 0.15mm and radio frequency of

12GHz.

c) Antenna surface may be deteriorated during long term outdoor usage, which causes

thicker water film on its surface. This may increase the film attenuation even with the

same rainfall intensity.

d) A common rainfall of 10mm/h intensity may form a 0.16mm thick water film on a radio

antenna. The common rainfall may cause up to 5dB water film attenuation in radio

transmission. The water film attenuation in radio reception will often occur more so in

the countries like Malaysia where rain is expected to fall throughout of the year.

In order to prevent water film on the antenna surface and/or reduce water film attenuation

during a rainfall, water repellent coating products are used as an effective countermeasure

against rainfall.

2.0 AVAILABLE PRODUCTS IN THE MARKET

As far as the water repellent product is concerned, we in Fujitsu Telecoms Asia neither have

no history of purchase nor experience of water repellent product application on radio

antenna in the past.

With the absence of buying experience and the water repellent product application on radio

antenna in the past, to get the right product from existing suppliers and even more so at a

cheap price for GX4000 application is expected to be difficult. However, a survey by the

internet search shows that there are several companies that produce water repellent

products but most of these companies are companies which are based in countries like the

US, Japan and Germany.

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Through an internet search, we have identified a number of water repellent products, but we

are not sure about the suitability of these products to be applied on to radio antenna (of

GX4000 Series).

However we will make further feasibility studies to the products which have been identified

based on information provided (information on the internet), and ultimately determine the

most appropriate water repellent product for radio antenna applications.

Among the names of water repellent products which we have been identified for further

feasibility studies are as shown in Table 1 below.

No Product Name Product Origin URL:

1 Hirec 1100 Japan http://www.hirecpaint.com/product_hirec1100.html

2 Drywired USA https://drywired.com/product/superhydrophobic-coating

3 Hydrobead USA http://www.hydrobead.com/#!shop--cart/c2jl 4 NeverWet USA http://www.neverwet.com/anti-wetting.php or

https://www.rustoleum.com/product-catalog/industrial-brands/neverwet-oem

Table 1: Available Water Repellent Products in the Market

3.0 FEASIBILITY STUDIES

The feasibility studies for selected water repellent products are based on the technical info

that we could find directly on the internet. Based on this technical info, comparison in terms

of their suitability for application on the radio antenna such as performance, effectiveness

and availability in the market will be defined.

Among other things that should be considered in feasibility studies to ensure we get the right

products also include the followings;

Grade of water repellent product (industrial, OEM, etc.)

Aerosol-based

Long lasting of the product when it is used

Material used (components to produce water repellent product)

Coating process (how the coating is applied on the radio antenna surface)

Negative effects (when selected water repellent product is being used)

Cost effective to purchase (where it was produced, local or overseas)

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Minimum order quantity, MOQ (if it is not a local item)

3.1 Hirec 1100

HIREC 1100 is produced by NTT-AT (NTT-Advanced Technology Corporation) and mainly

used to protect its critical telecommunications equipment from snow, ice, and rain

interference. NTT-AT is headquartered in Kawasaki-shi, Kanagawa, Japan. NTT-AT also

has office in Nierstein, Germany.

Hirec 1100

HIREC 1100 is industrial-grade product and a super hydrophobic water-repellent coating

material, provides hydrophobic coatings with a contact angle of 150° or more between an

object and water droplets, resulting in higher performance and durability. Conventional

water-repellent coatings, by contrast, can only provide a maximum contact angle of

approximately 100°.Hirec 1100 is a Super Hydrophobic Coating for Antenna, Radome and

Other Public Infrastructure.

Water Film Attenuation Calculation

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Water film attenuation of over 5dB in radio reception may occur at water film thickness of

0.15mm and radio frequency of 12GHz. Rainfall forms water film on antenna surfaces. The

water film may cause water film attenuation in radio reception. The water film attenuation is

calculated for radio frequency of 3 -25GHz and water film thickness of 0.05 - 0.20 mm.

Water Film Attenuation Calculation gives the following results;

Water film attenuation increases with thicker water film and higher radio frequency.

Attenuation is over 5dB at water film thickness of 0.15mm and radio frequency of

12GHz.

A common rainfall of 10 mm/h intensity may form a 0.16 mm thick water film on a

radome (*2). The common rainfall may cause up to 5dB water film attenuation in

radio transmission.

Antenna surface may be deteriorated during long term outdoor usage, which causes

thicker water film on its surface. This may increase the film attenuation even with the

same rainfall intensity.

Super water repellent compounds in Hirec 1100 prevent water film on antenna. Hirec

1100 is an effective countermeasure against heavy rainfall.

3.2 DryWired SHC

DryWired SHC (Super Hydrophobic Coating) is also an industrial-grade product and a

super hydrophobic aerosol coating formulated to repel rain, snow, and ice. Packaged

conveniently in an aerosol can, this easy-to-apply single-step spray dispenses solution that

forms a super hydrophobic film to repel the most harsh weather conditions like heavy rainfall.

DryWired SHC

Through the modification of chemical and physical surface properties, this formula is able to

achieve contact angles over 160 degrees. SHC is primarily designed for application to

satellite dishes and other outdoor communications fixtures to mitigate signal attenuation

caused by natural elements.

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However, it can be used for a variety of applications that can benefit from its unique ability to

repel rain, sleet, snow and greatly reduce ice build-up. Among the main uses of DryWired

SHC is on;

Radomes (greatly reduces signal attenuation on radomes for consumer, commercial,

and industrials applications).

Satellite dishes

Radars

Antenna Arrays

Windmills

Outer airplanes parts: nosecone, wing, rutters, horizontal stabilizers.

While the main characteristic on the DryWired and what makes it very effective when applied

are as listed below;

Super Hydrophobic (contact angle greater than 160 degrees)

Oleophobic or also known as lipophobic (it refers to the physical property of a

molecule that is repelled from oil). The most common lipophobic substance is water.

Single-step Application.

Spray and dries within minutes.

Adheres to a variety of substrates including plastic, metal, and painted surfaces.

White matte finish.

Intended for use on surfaces that will be left untouched and not exposed to abrasion.

Additional information on DryWired SHC can also be found at the following URL;

https://drywired.com/wp-content/uploads/2015/12/SHC-Aerosol_SDS.pdf

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3.3 Hydrobead

Hydrobead aerosol-type is an industrial-grade product and also a super hydrophobic

material, and water is actively repelled from a treated surface. Water-based liquids roll right

off a surface on contact and leave materials clean and dry.

Hydrobead

Super hydrophobic technology means super dry materials. Normal waterproof coatings

simply slide water off of a surface. With Hydrobead, water is actively beaded and repelled. It

practically never touches the surface! Hydrobead has a one-step application. Simply spray a

desired surface, let the coating dry, and you're good to go.

Hydrobead is an aerosol-based, single-spray application with extremely water repellent

properties, leaving your surfaces clean, completely dry, and damage-proof. The main

characteristic on the Hydrobead and what makes it very effective when applied are as listed

below;

Single-step application: spray a desired object and let dry. That's all there is to it. Dry

times vary but at least 20 minutes is recommended. Spray dries clear on some

materials and to a slight white mist on others.

Net weight 11 oz (312 g), covers 20 sq. ft. (1.9 sq. meters)

Coating can last multiple years; heavy exposure to rubbing, handling, and agitation

greatly reduces lifespan. Not meant for use with soaps or oils.

3.4 NeverWet OEM

NeverWet is a super hydrophobic treatment that dramatically repels water, oil,

grease, mud, ice and other liquids. Liquids form nearly perfect spheres which roll off

surfaces keeping items dry and clean, and suitable for antennas, satellite dishes,

metals, woods and more.

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NeverWet OEM

NeverWet® Multi-Purpose OEM above is a super hydrophobic treatment with a new

revolutionary of class of coatings causes’ water to form nearly perfect spheres which roll off

the surface keeping items dry and clean. NeverWet is a two part treatment consisting of a

base coat and top coat that work best on wood, metal, concrete and masonry. The multi-

purpose treatment dries to a flat, milky haze.

Efficiently coat large equipment

NeverWet OEM is more durable than NeverWet aerosols (and for aerosol type,

NeverWet do not have adequate distribution in Asia Pacific region).

Volatile Organic Compounds (VOC) compliant. The organic compounds are derived

from the petroleum distillation process and are used as solvents, drying agents and

cleaning agents in various printing processes.

After base coat is applied, wait 45 minutes and apply top coat. NeverWet will repel

water after 30 minutes. Wait 12 hours for optimal performance.

4.0 FINAL CRITERIA IN CHOOSING RIGHT WATER REPELLENT PRODUCT

The shortlisted water repellent products should at least fulfill the following criteria’s before

the best of best product is finally chosen. The very least, the product selected (final product

chosen) must have the following criteria;

Industrial-grade

Aerosol-based coating

Suitable for radio antenna application

Best Price

Shortest Lead Time

MOQ (if product is produced overseas)

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5.0 SPRAY-ON COATING PROCESS

To make the radio antenna surface is super hydrophobic; the water repellent spray-on

coating product shall be carefully applied on the target surface. The following step by step

processes shall be followed;

<Step 1> Clean the target surface and make sure it is dry and free from dirt or dust

Clean the surface of the radio antenna (GX4000 Series) is about to spray. This is to ensure

that the surface is dry and free of dirt, dust or debris. The water repellent coating product

work best when it sprays directly on dry and clean surface. Use paper towel, clean towel or

anything else to wipe the surface with while leaving it free of any chemical or moisture on

top.

<Step 2> Shake well to mix the water repellent liquid.

Particles may have fallen out of solution while the can was at rest. Shake vigorously for 1 or

2 minutes to ensure the content of the can is properly mixed again and ready for optimal

super hydrophobic coating.

<Step 3> Spray!

Position the aerosol-type can 8 to 12 inches away from the target surface and spray. Motion

up and down, and side to side until the surface area is covered. Make sure not to overdo for

a single coating while the water repellent liquid may pull-off.

Multiple layers of water repellent liquid can be applied atop each other for better

results. Before applying an additional layer of water repellent liquid, be sure that the previous

layer is completely dry.

<Step 4> Give some time for water repellent coating to dry

The water repellent coating liquid takes a little time to dry. It is recommended for leaving it

alone for about 15 to 20 minutes until the coating is dry of the touch. Water repellent coating

dries to a misty white haze on some materials, so be sure to test a small area first to ensure

satisfactory results.

6.0 MAKE YOUR CHOICE

Based on the criteria in choosing right water repellent coating product in clause 4.0 above,

the following Table 2 shows the Engineer choice and shortlisted water repellent coating

products that could be purchased.

Choice No. Product Name Advantages & Disadvantages of the Products

Price per can (in USD)

1 Hirec 1100 - In general Hirec 1100 is more expensive than the other two.

140.00

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- FTA can ask counterpart in Japan to buy and hand carry to Malaysia. MOQ is ignored.

- Appropriate for radio

antenna application.

2 Hydrobead - Hydrobead is cheaper than the other two.

- International shipping will be via Fedex or DHL Express International Air. International air shipping is very expensive since the coating is a flammable liquid.

- Longer lead time

- Appropriate for radio antenna application.

19.50

3 DryWired - DryWired is moderate in price compared to the other two.

- International shipping will be via Fedex or DHL Express International Air. International air shipping is very expensive since the coating is a flammable liquid.

- Longer lead time

- Appropriate for radio antenna application.

54.95

Table 2: shortlisted water repellent coating products

7.0 RECOMMENDED PRODUCT

In the present study, MOQ and lead time for Hydrobead are still not sure. This is because

FTA has never purchase similar products from the USA. After all, we expect a higher cost if

the product is purchased directly from the USA because shipping fee for flammable products

such as Hydrobead and DryWired will be very expensive (if they use the services like Fedex

or DHL Express International Air for delivery).

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Therefore, in my opinion, the main option is to select and purchase Hirec 1100 from NTT-AT

of Japan.

8.0 CONCLUSION

As the conclusion, the first choice (or option) is to purchase Hirec 1100. However, FTA still

have time to do more research, especially to get more information on product pricing, MOQ,

lead time and shipping cost from USA to Malaysia.