We don't follow. We innovate

We don't follow. We innovate

Thursday 31 October 2013

Correlation between LSPs to watermark stains and other stains.

Many new detailing enthusiasts are especially excited over any new LSPs aggresively and cleverly promoted on the Internet, and as usual, most websites only focus on the pros of these promoted LSPs.....and not the cons. It is not common to see any blogs talking about the "side-effects" of LSPs. 

Based on my own experimentation and long term observation, I am absolutely sure that certain types of natural waxes, synthetic waxes, synthetic sealants, coatings, and even detailing sprays can increase or decrease staining on a detailed automotive paintwork. 

When it comes to LSPs, detailing enthusiasts tend to rely mainly on the Internet to find out what's "hot" out there, and the classic topic of "water beading" is always the most popular marketing tool to attract consumers as its the only visible characteristic of the LSP that immediately stirs up consumer excitement. But with water-beading aside, Im more interested in stain-resistance or increased susceptibility to staining. 

NOTE:
Japanese LSPs (eg: synthetic waxes and sealants from Soft99, Willson, Taihokohzai)
I have access to loads of Japanese products imported directly from Japan, and based on my testing of the fantastic water-beading Japanese LSPs, all the products that I tested (more than 20) eventually led to serious staining on all types of paintwork on vehicles that are uncovered 24hrs and washed once a week. Important to note that before using these LSPs, these vehicles did not encounter such problems. 

Lately, I had 7 customers who participated in a new 3month test. Previously their vehicles were tested with all sorts of highly promoted coatings, sealants etc, and most ended up with serious and mild staining problems. This time, the LSPs were fully stripped, paintwork fully prepped and then applied with "old school" LSPs....such as Autoglym's classic SRP, Autoglym's EGP, Soft99's grossly outdated RainDrop, Swissvax's Mirage, the classic Klasse Twins, Zaino Z2Pro, and even Meg's old school Cleaner Wax. These are the Clint Eastwoods and Roger Moore of the detailing world. 

Each vehicle wax parked outside daily, and washed only once a week using Amway's car shampoo which doesn't have any wax. No spray detailers were used. 

After 1 month: 
1. None of these cars had any watermark issues. 
2. Even when very dirty, all stains were easily washed away, especially those dreaded black vertical lines on white cars. 

Shocking. 


 





  

Tuesday 15 October 2013

Serious Watermarks - possible connection to COATINGS

Pics below were taken by owner of a Passat CC that's meticulously cared for. The owner is a hardcore enthusiast who owns many luxury vehicles and each one is washed once every 5days. Historically, his vehicles were all detailed by my establishment using synthetic sealant as LSP (after intensive prepping), and undergo maintenance detailing every quarterly. Over 4years, none of his cars' paintwork had any problems. 

When the CC was purchased, the salesmen persuaded the owner to try the new "coating" (nice commission for the salesman) and that's where the problem started. I have tested these stuff a long long time ago and have always had reservations about them, and I have cautioned the CC's owner. 
The CC was sent by the salesman to a highly promoted and highly advertised establishment in Sunway. 

Approx 5weeks after the 4-figure "coating" was done,  the owner called me to his house to look at the car. 
It was the first time in his years of car ownership that he has encountered this "unusual problem" (his words). 
The pics below'll give you a good idea of what I'm talking about. 

All sorts of watermark-remover chemical were used. 
Vinegar, claying, full strength APC, all kinds of mild solvents etc......to no avail. 

Woolpad with Megs 105: hopeless. 
Osren's aggressive "jeans pad" + their most abrasive compound : very slow progress. 
Fianlly, the CC had to be wetsanded, and that removed the problem. 



I have heard from many experienced detailing suppliers and pro detailers in the industry lamenting that watermarks appear to be a "new problem" caused by many kinds of "coatings". No one knows the actual reason/s behind this. Many have tried applying carnauba wax or any other LSP on top of the coating to protect the coating and hopefully reduce the watermark problems. To me, this is lunacy. 
Paint protected by clearcoat
Clearcoat protected by coating
Coating gives problems. 
LSP on top of coating to hopefully prevent problems. LOL!

I have used loads of different coatings very selectively only on specific colours and strictly for certain types of customers only. In many cases, where the vehicle was very frequently washed and well maintained, I have observed the same watermark problem. 

So, my advice to my customers: 

Coating is not a perfect, magical armour that protects the paintwork from everything. 
Based on my experimentation, coatings are merely LSPs that remain on top of the clearcoat much longer than other LSPs such as waxes and sealants. But DURING that duration, depending on how its maintained, your paintwork might still become rough, stained and scratched. 

After all, I cannot believe that coatings manufacturers are much "cleverer" than established automotive clearcoat manufacturers who spend millions on R&D and have been in the market for decades or even generations. 

If a product works well in Japan or the UK, it doesn't mean it'll produce the same results here in our hot humid climate with our unique rainwater composition, and different types of contaminants. 





Monday 5 August 2013

"Dynamat" might NOT improve your door speaker's sound

Answer:   Not necessarily so.

Look at home hi-fi speakers, where lots of effort is spent to stiffen and strengthen the speaker enclosure (speaker box).  Using logic, if you want maximum solidity, you can mount the speaker onto a concrete or cement box, and it'll be stiff as hell. But that won't necessarily give you great sound. It's not that simple. Stiffness does lead to reduced resonances, buzzing and vibration. But stiffness has nothing to do with tonality or the characteristics of the reproduced sound.

Similarly, if you want a great handling car, you can easily seam-weld the entire body, and strengthen it to the max like a race car or rally car. But doing this on a daily-driven car on normal asphalt roads, will result in atrocious comfort.

Any vibration damping material applied to the door can certainly dampen any vibrations by adding mass to the sheet metal. It makes the speaker sound more "solid" and "tighter".  But the actual tonality and "liveness" might be worse than before. It's not so simple as "more Dynamat is better".

Too much damping material on your doors could lead to a "dead" sounding tonality where there's no character or liveness to the sound. If its SPL, you could have a point. But if its SQ (Sound Quality), I do not agree with the perception of "more Dynamat is better"

If you want your door speaker to perform at its best, never just mount them on the factory locations and hope for magical results.

1. Take measures to strengthen the mounting location.
2. Angle the mid-basses. Huge difference.
3. Speaker should not be too deeply recessed behind the grille. Minimise obstructions.
4. Do not use the original restrictive grill. You'l be surprised how much sound it obstructs.
5. From my experience and experimentation, use at least 80W RMS on each door mounted mid-bass driver.


How To Reduce Tire Noise/Road Noise (continued...Step 5)

Step 5

Doors.
Road noise penetrates the door's thin metal skin and reverberate within the door cavity. This booming noise exit the door cavity via those big holes in the door's metal panel, penetrate through the plastic door card into the car's interior,

Remove plastic door panel, and look at the big holes in your metal door panel (inner panel).  Look through the holes at the OUTER metal panel. That's the panel where most "enthusiasts" will cover every sq ft with vibration damping sheets. From my experimentation and experience on more than 500 vehicles, that's a waste of money and adding unnecessary weight to the door unless you're a serious car audio enthusiast.
Use small strips/pieces of vibration-damping sheets to do "spot damping" on that panel. Since it won't block or absorb any noise...so go easy with it. If you see a side-impact protection bar, look at the tiny gap between bar and the metal panel. Slide some thin closed-cell foam into that gap. Or use a small piece of damping material. The idea is to add a separation layer between bar and panel. This will tremendously improve the sound of your door closing (which somehow appeals to many car owners).

Then, look at the INNER panel with all those holes (depending type and make of vehicle). Any hole of any size must be covered up. Simplest would be using Dynamat or equivalent. Best would be any "noise barrier" material such as Mass-Loaded-Vinyl which might or might be common in your country. If your vehicle is not a high-end audio vehicle, it's not necessary to cover every inch of that metal panel. It's sufficient to merely cover up those holes.

After performing the above, any residual noise will penetrate the plastic/vinyl door panel. At the underside of the plastic door panel, you can add a thin layer of material to either absorb or block noise. It can't be too thick, or plastic door panel might not re-fasten easily onto the metal door panel.
Experiment and use the thickest possible material.

If you're on a very low-budget, you can use any kind of felt or carpet underlayment or jute.
This can be found under the carpet of most cars. Alternatively, you can use closed-cell nitrile rubber such as Ensolite (USA), or Insulflex or Superlon. If your budget is ample, my favourite method is:
a. Few small pieces of vibration-damping material evenly spaced out.
b. Any "sound barrier" material such as MLV (Mass Loaded Vinyl).
Accumat has a product that features MLV (AMT250) and this MLV is sandwiched between foam. Dynamat's equivalent is Dynapad. But pls note...these kinds of multi-layered sound barriers are usually expensive but highly effective.
c. Follow up with a layer of 3M Thinsulate to absorb and dissipate any residual noise.


Step 6
Front Kickpanel Areas - (eg: behind your throttle pedal)
This is the area where the most tire noise penetrates greatly into vehicle interior as it's extremely close to the tires. For max results, 1 layer damping + 1 layer barrier (eg: Accumat 250, Dynapad etc) + 3M Thinsulate.

In totality, if Step 1-6 are performed, I'm highly certain you'll experience a hugely noticeable significant reduction in road noise/tire noise levels. However, if you still want to go further, the most practical further step is to change to quieter brand new tires.












Thursday 25 July 2013

Soundproofing - How good is Insulflex ?

INSULFLEX was designed as a heat/cold insulating material (thermal insulation)...and NEVER for acoustic control/soundproofing purposes. It's mostly used in the air-conditioning and other similar industries that require thermal insulation. In the US, Ensolite is also similar to Insulfex and its primarily a thermal insulating material.

In Malaysia, certain parties had easy access to this material a long time ago, and started promoting it to car audio shops as being a suitable "soundproofing material". Being "foam like", relatively light, inexpensive and appearing quite dense, it has led most car audio retailers (in the older days) to believe that it can be profitably used for "soundproofing" applications.  In current times, where consumers are highly image-conscious and love idolizing high-end brands, other purpose-made, premium priced soundproofing materials are heavily promoted on the Internet. Meanwhile, for car enthusiasts with budget constraints, their favourite websites and forums have also heavily promoted Insulflex as an alternative "soundproofing material"...relatively cheap and easily available.

Insulflex is a closed-cell nitrile foam rubber for thermal insulation.
Being closed-cell and not a few inches thick, it is not an effective sound absorber, especially the low-frequencies. The manufacturer has specified its NRC (Noise Reduction Coefficient - related to absorption) as a merely 0.14.  The max is 1.0

And since Insulfex is not a heavy material, it does not possess the mass necessary to function as an effective noise barrier material (to block noise)..especially the low-frequency portion of that droning, rumbling tire/road noise. Effective sound barrier materials are minimally 1lb per sq foot (such as Mass Loaded Vinyl).

Nevertheless, Insulfex is still capable of noticeably muffling and reducing the amplitude of higher frequencies of tire and engine noise. If you're on a very strict budget and cannot tolerate heavy soundproofing materials in your vehicle, Insulflex one of the low-budget methods to produce noticeable results. 

My suggestion for low-budget soundproofing with Insulflex:
Use small pieces of damping sheets (eg Dynamat etc) to spot-damp your doors, firewall, fender hump etc, and then lay the maximum thickness of Insulflex on top that allows carpet to be re-secured.

On most Jap cars, my main targets to be Insulfex-ed in a low-budget job that can be done in stages (ranked according to importance)
1. Underside the hood.
2. All doors (ensure all holes are covered by damping sheets first)
3. Front kickpanel area x 2
4. Rear wheel hump x 2

Once you've done the above, and assuming your tires are not badly worn and your wheel bearings are OK, you'll definitely hear a noticeable improvement.

Tip: 
If your vehicle is externally parked for long periods in hot weather, Insulflex within your headliner is an excellent way to enjoy a cooler interior. Works great.  







Monday 22 July 2013

How To Reduce Tire Noise/Road Noise

Road noise/Tire noise: This droning and rumbling noise is mostly produced by the tire tread's interaction with the road surface, and the noise is mostly low-frequency in nature. Your typical damping sheet (Dynamat etc) will never block or absorb such low-freq noise. It was never designed for these purposes. Neither will any closed-cell or open celled foam. For effective absorption of low-freq noises, you'll need at least a few inches thick of fluffy materials (such as jute, rockwool, fiberglass etc).

This common complaint (tire noise) should be your 1st target to attack in most modern vehicles. The strategy below gives the best Bang for the Buck results.

 Step 1: Wheel arches 
This area is the closest to the tire...the source of this noise. The shape of the wheel arch's interior and the air space within will amplify certain frequencies, and these will easily penetrate the metal into your interior. Spray each wheel arch with few layers of rubberized undercoating (3M,Bondo, Duplicolour, Sikagard etc). You can also use the brush-on type from many soundproofing materials manufacturers (eg StP's Mastic, Secondskin etc). Get this coating as thick as possible. Treat your wheel arch liners with the same product, attach a damping sheet to the underside of the liner, and stick a piece of 3M Thinsulate on top).

Step 2: Undercarriage 
Do the same thing as per your 4 wheel arches. The above Wheel Arch and Undercarriage treatment should always be your 1st soundproofing activity as you are addressing the areas closest to the NOISE SOURCE. The above will give you a significantly noticeable result without stripping any of your interior bits. Once you have done the above, and if you feel you want to improve it further, and you're on a tight budget... 

Step 3: Door hinge area
Open your front doors and look at the top and bottom door hinges. Look at the area between the 2 hinges and BEHIND them...there's usually a gap that leads into the front fender. This is a critical area, and hence, many car mftrs (especially VW) pay special attention to this gap. Squeeze any closed-cell, non-water absorbent material to totally seal this gap. Makes a huge difference in tire noise intrusion into cabin. VW uses foam blocks and even then, there's still some small gaps around these foam blocks. You can use silicone etc to ensure a good seal as lots of noise easily penetrates through the smallest hole.  Remember...we're on a tight budget and addressing the main critical areas pertaining to irritating road/tire noise.

Step 4: A, B and C pillars. 
Tire noise comes from the lowest part of the car, enters the hollow door sill, penetrates into the pillar's bottom and the noise shoots upwards to the interior roof. Hence, certain vehicle's A, B and C pillars are fully foamed or partially foamed at the assembly plant or have some kind of fluffy materials stuffed into them. Foaming the pillars is often recommended by retailers who're heavily into offering foaming services. The foam cannot block all frequencies and because its closed-cell nature, it can't absorb most low frequencies well either. Foaming can produce respectable results but bearing in mind the cost of foaming, you can stuff the A, B and C pillars with fluffy polyfill (used to stuff speaker enclosures) or even the new 3M Thinsulate which is light, highly sound absorbent and hydroscopic). Treating your pillars, especially the A pillar makes a significant difference in lowering tire and engine noise. Why? Engine noise easily penetrates your hood, and the oncoming wind carries this blanket of noise, and slamming it onto your windscreen (which transfers the sound vibrations onto the A pillars), and the external noises also penetrates the pillars and amplified by the hollow space within the pillars.

 The above 4 steps are the first few things you must do when addressing tire noise, and once done, anything else will be really labour intensive and could start getting expensive cos you might end up following the others who're doing the wrong things and using materials in the wrong manner. I will get elaborate on Step 5 a while later as its late now...Yawnnnn!

Truth About Soundproofing Your Car

Most information you obtained on vehicle soundproofing are MAINLY derived from the Internet....from articles and websites created by suppliers of soundproofing materials and car audio retailers who perform sound proofing jobs.

 As per usual marketing sense, their marketing objective is to:
1. Promote their brands
2. Increase usage quantity and usage of a wide variety of their materials.

Hence, you still see the outdated, old-school approach created by the early leaders in this industry where the entire car flooring and firewall are covered by shiny damping materials. Just imagine the weight increase and tremendous cost without any guaranteed results!.

The noise that envelopes you in the car interior are a combination of engine noise, tire noise, wind noise and external traffic noise. These MUST be kept in balance. Eg: Aggresively reducing 1 type of noise could make the other noises more apparent/louder. Even a Lexus is not 100% quiet, as a perfectly quiet car makes you feel uncomfortable, just like staying late at office with the air-conditioning and other stuff switched off. It gives that eerie sensation if you're not used to it. Complete silence can be deafening.

Due to excitement generated by the media, many car enthusiasts jump into "soundproofing" their vehicles using these "classic" methods and approaches such as using loads of costly and heavy asphalt and/or butyl-based damping materials (eg Dynamat,GSI etc), and slathering these materials all over the car. Many have convinced themselves that there's an improvement while others have been quietly disappointed. Many have even used materials for home roofing (Peel and Seal) simply due to its lower price, and believing that these are equivalent to damping sheets meant specifically for automotive sound damping without considering its effect in the longer term and adhesive quality.

Many car owners have their own approaches such as heavily doing up the 4 doors with damping sheets without even knowing IS the problem mainly contributed by the doors themselves!. Others will vigorously attack the floor. The above is the main reason why many car owners are experiencing the "high-end hi-fi syndrome" when it comes to vehicle soundproofing...a never ending, expensive pursuit to chase after different elusive targets. A never-ending game. In short, most owners have never investigated: 1. What is the main type of noise that annoys them? 2. Where is this noise mostly emanating from? 3. What's the most cost-effective method to give the most "bang for the buck" results? On modern vehicles, the No1 noise problem is mostly tire noise/road noise, and my next blog deals with this issue.

Monday 18 February 2013

Is that $500 or above Carnauba Wax any good?

Any Carnauba Wax or basically any final layer that you apply is merely a form of protective cosmetic.
It does not correct your paintwork's flaws.

As to whether a $500 and above Carnauba Wax is any good, it fully depends on the quality of your paintwork, and the extent+quality of surface prep work (aka compounding and polishing) that has been done on that paintwork.

On a brand new Mazda (example) imported from Japan, if only a mild polishing is done, and topped with super premium Carnauba Wax, you won't be impressed. On the contrary, on a new VW or BMW, you'll see a much more impressive result.

The lesson here is:  Your wax or final layer contributes the LEAST to the final results.
It's all in your surface-prep (eg: sanding, compounding, polishing etc)
It's 100% identical skincare.
Your surface prep is "skin treatment/skin correction". Once your skin is looking at its best, then its time to progress to using the best "cosmetics" (waxes, sealants etc) you can afford. Get your "skin" right first.

If the paintwork quality is average or above average, and extensive prep work has been done, you've already achieved close to 90% of the final looks, and any quality waxes or sealants will provide that last 10% in terms of richness, gloss and optical depth. No wax, no sealants and no coatings can serve as a "magical last layer" that'll turn an average quality paintwork (+ simple polishing) into a show car look that'll turn heads. 90% of the final looks will be determined the extent of the surface prep and how your surface prep were done.

Most synthetic waxes (eg Meguiars NXT) and natural carnauba waxes (eg Swissvax, Zymol etc) tends to darken the colour, which enhances the ILLUSION of vibrancy, depth and gloss. This is especially great on dark colours and black.

 However, IMO, on silver, white and other light colours, I don't want any waxes or LSPs that has a "darkening/richening" effect, as they tend to make these colours appear less bright and appear dull, without the bright "popping" effect. I never use Carnaubas on light coloured cars or pearl finishes. On such whites, silvers and light colours, you could try an average of 3 layers of a great synthetic sealant that doesn't change the colour at all (eg: Zaino Z2Pro, Jeff's Werkstatt, Klasse Twins, Duragloss 105, hundreds of Jap synthetic sealants, Turtle's ICE etc).

 Certain synthetic waxes such as Collinite 845 is also superb on whites, light colours....and especially silver. The above approach makes the silver and white look as "bright" as possible with no darkening effect. These colours will look vibrant and reflective, giving the car a sharp look.

Premium priced tyre shine - necessary?

I have tested more than 25 different tyre shine products over a 10yr period and my conclusion is: 1. The more expensive ones will usually remain on the tire sidewall longer than the cheapo ones. Note that I said REMAINED. The product might be chemically present on your tyre sidewall for 1month, but it does not mean your tyres will be super black with a wet look for 1 month with/without washing. The mere presence of the chemical on your sidewall has nothing to do with how fantastically glossy your sidewall looks like. 2. Any tyre shine product is affected by heat. It might look nice and glossy upon application, but drive at 60mph for 30mins, and you'll that the initial wet look has died down to a more "satin shine" finish. 3. Any tyre shine's gloss level is hugely affected by the sidewall's material (type, texture etc). Most ultra low profile tyres tend to exhibit a much higher gloss level when you use even a cheapie tyre shine. When you review tyre shine products, always test it on the same brand and same size of tyre for an accurate impression. 4. The best results are obtained on 100% clean sidewalls. Don't waste car shampoo on your sidewalls. Wear gloves and brush your sidewalls using powdered laundry detergent or Bon Ami (or other powdered detergents) or dishwashing liquid or full strength multi-purpose cleaner. Scrub until the suds are no longer dark grey/black. Dry the sidewalls completely, and apply your tyre dressing.

Expensive Car Shampoos - necessary?

Car shampoos are the highest volume sellers in the detailing products market, and naturally, mftrs have CREATED a need for premium-priced shampoos to entice car enthusiasts. Premium-priced shampoos with glitzy packaging and hyped with "marketing fluff" aren't gonna make your car any cleaner than a normal car shampoo. If you know how to wash your car properly,spend the proper time to do it correctly, and wash often, any ph-balanced car shampoo from any reputable mftr will the job equally well. If you want your layer of wax or sealant to last as long as possible, MINIMISE contact with any car shampoo or any detergent. Wash with your mitt and rinse immediately. There is no benefit in leaving the shampoo suds on a surface that you've already agitated with your wash mitt unless that surface is extremely stained and thus, require extra dwell-time to loosen the stains. If you do a blind test on 2 identical cars, with each being properly washed with different shampoos, no one can tell the difference. Can you tell which brand of shower gel I used last night? NO.

Thursday 24 January 2013

Should I buy that NEW Peugeot?

It's tempting to get that stylish turbocharged new Pug model that's so attractively priced.

Before your purchase, pls be mindful of the following:

1. Never expect your Pug to be as reliable as your Jap car. It will never be.

2. Ask about the warranty...how much do you need to spend at each warranty service?
eg: The price of the automatic transmission fluid might blow many people away.

3. Do you have a spare car?
Again, don't expect a super fast service. Your Pug might need to be left at the service centre for more than a day.

4. Prices of rims.
On our atrocious roads, its common to damage our rims. On Jap cars...no worries, replacement rims are cheap and easily available. You can't just waltz into any tyre/rim shop and ask for some Peugeot rims cos they have a Frenchly-unique rim offset. So, if your Pug rim needs to be changed, you could be in trouble. New Pug rims (OEM-type) are extremely expensive.

5. Be careful of the common problems...such as the De-Pollution Warning Issue, caused by excessive carbon buildup on the inlet valves (yes..INLET). This is caused by the EGR system that re-routes a little of the exhaust gases into the inlet valves to be re-introduced into the combustion chamber. With anything less then RON100 fuel and always gently driven, carbon will buildup on the inlet valves and this could even lead to harmful knocking/detonation. Very common on all Pugs globally EXCEPT in Japan where RON 100 fuel is available.

Juddering Wiper Blades - Incorrect Wiper Arm Angle

Assuming your rubber blades are not worn out, and your windshield is 100% uncontaminated and smooth, the other cause could be your wiper arm's angle. This is most common on older cars. 

Imagine using your glass squeegee to clean your glass panel. 
As you pull the squeegee down, the tip of the rubber blade faces UP. 
This gives you a clean, smooth sweep downwards, and you have a dry and clean glass panel. 

Your wiper blades operate on the same principle. 
As the wiper arm goes upwards, the rubber blade's tip faces DOWN. If the tip faces upwards, that rubber blade won't go upwards smoothly, and it'll judder. 

When wiper blade reaches the top, the rubber blade should immediately and noiselessly change direction. 
On the downward stroke, the rubber blade's tip shd face UPWARDS as the wiper arm pulls the rubber blade downwards. 

If your metal wiper arm is bent, the above might not happen, and you'll have juddering issues. 

To check, look at your wiper blade at its resting position. 
Ideally, the wiper blade must be exactly perpendicular to the windshield, meaning its 90degree to the windshield. If it's not, then use pliers and twist the arm until the wiper blade is perfectly perpendicular to the glass. 

BMW and Mercedes even have specialized wiper arm-twisting/alignment kits for this purpose.  

Wednesday 23 January 2013

Juddering Wiper Blades - Causes and Solution

Juddering wiper blades is a common problem, and most car owners attribute it to the wiper blades. Very common for this problem to persist even after changing to new blades. Based on my testing, the most probable No1 culprit is your windscreen....contaminated. It can be contaminated by: Waxes, silicon oils from your car shampoos that contain waxes Airborne contaminants that have etched onto the glass Water-repellant products (eg: Rain X etc). These contaminants are very difficult to remove even by using solvents and strong chemicals. When water is sprayed onto windshield, the water beads up, and this indicates the presence of a layer of "something" that's on the windshield. Most often, its this layer that causes the wiper blade to judder. This layer of contaminant must be removed. After removal, water will remain as a continuous flat sheet on your windscreen. At this stage, a good-condition wiper blade will operate with minimal friction and hence, be quiet and smooth. It acts as a squeegee, and with just 1 pass...will clear the water and reveal a dry and clear surface. The easiest, fastes, safest method to 100% contamination is to use Cerium Oxide Powder. This is a brownish powder used by glass specialists to polish glass without scratching it. My personal favourite is a product from Soft99 called Glass Compound Z. Used as directed, it totally removes all contaminants from your windshield, including hard-water marks. Once your windshield is 100% clean, replace your contaminated wiper blades with new ones to ensure that BOTH wiper blades and windshield are now totally clean. Regularly clean windshield and rubber blades using ammonia-based glass cleaner to remove any wax deposited by your car shampoo.