The acid watermark removal is never meant to be used on the wiper area of the front windscreen as there are scratches and stone chip. The acid will fill into the holes of the scratches and make it blurry. This is not the 1st time happened.

The remedy is to polish put the acid at the scratches by using heavy paint correction compound.
The pro will be using Meguair's m105 or Glass Compound such as Osren or CeriGlass

For Consumer - use the glass compound such as Soft 99 Glass Compound Z which is available at Brother's Kelana Jaya for about RM 30+. If that's too far, you may use Autosol Metal Polisher in toothpaste that is available in any hardware shop or hypermarket. It may cause micro (tiny) scratch, not naked eyes visible but against sun light as it is not meant for glass.

Be prepared to rub and rub (many rounds) to see improvement.

If left uncorrected, the blurriness will disappear after 1/2 year to 1 year time depending on the taken to dilute acid from the scratch. If you cant's wait and want a quick solution and willing to pay, is to sent to the pro detailing shop and the normal charges are between RM 150-RM 250.

Normally, the acid is only used when the glass is heavy stained . Acid is the fastest but not the safest way to clear watermark on windows.

The above are based on actual experience when used a similar acidic product brought at hypermarket.

This post has been edited by mot88: Feb 10 2016, 05:08 PM

Soft 99 is the best consumer product specifically formulated for glass compound and the price is cheap compared to professional product but still behind Autosol metal polisher in term of cutting ability.

If pro product (Carpro/Meguair's/Osren) = 100%, Soft 99 Glass Compound Z is 70% and Autosol is 75 to 80%. All glass compound will contain Cerium Oxide, suspect Soft 99 contain it as it is orange in color but unable to find the spec of it.

leeweixian88, I don't have any recommendation for car detailing shop.

This post has been edited by mot88: Feb 11 2016, 07:50 PM

leeweixian88, quite a number of ppl was like your predicament back years ago. I was digging up old posts where acid WM removal was the rave back then.

http://autoworld.com.my/forum/index.php?/t...ter-mark/page-4

Read through page 1 to page 3. The participants in this forum are individuals who are passionate with detailing
http://autoworld.com.my/forum/index.php?/t...dscreen-polish/

As elaborated, the blur/ white spot will clear in due time and just matter of time, in months , not years). Not sure what compound that the car saloon used but Meguiar's Professional line M105 (Meguair's Ultra Cut Compund) is one of the used and abrasive compound at that time. Now there is a new product M101 (Meguiar's Foam Cut Compund) which much more abrasive than M105. Professional line is usually used with machine, cannot unleash 100% of power if used by hand.

I m not sure if you are willing to spent more money to go to car saloon who use M105 or M101 for polish or seek the windscreen replacement route as discussed also in the above thread (2nd link).

If you choose to replace the windscreen, important point to, avoid driving the car if possible or else go slow on hump ,uneven surface during the glue curing process (up to 12 hours). Why? Coz, the windscreen is subject to vibration pending hardening of glue and any big impact will cause the siting of windscreen to shift a bit and gap.
If there is a gap, it you will hear a slight sound of wind coming in (when you off yr radio) when doing 110km/h and above.

I hope you would make a sound decision based on the above information.

Previously, some used Meguairs M105 and machine polish off the blurring due to acid. Can also try to use commercial alkaline based cleaner (such as EP Eco- Kleen sold at HomePro at tiles section) to neutralise the acid. The blurness will disappear after months, usually 6 to 12 months if nothing is done.

This post has been edited by mot88: Apr 4 2018, 11:47 AM