A Driving Instructor's Blog

Cleaning The Windscreen – Inside

Have you noticed a whitish film on the inside of your windscreen – visible especially when the sun shines on it at certain angles? No matter what you do, it won’t come off? It is apparently due to a build up of hydrocarbons from the aircon and plastic components in the car (this is what I’ve been told). Personally, I think that cigarette smoke, vaping residues, kids, and pets have a lot to do with it as well, not to mention when people use the back of their hand or a dirty rag to wipe morning condensation off. Certainly, it will build up again over several months if you get it off. But how do you remove it in the first place?

Use a 5% solution of sodium lauryl sulphate (SLS), wipe thoroughly, then clean again using Autoglym Fast Glass.

Alternatively, I think I have found the ultimate solution in Traffic Film Remover – as detailed in this article. Sugar soap, also mentioned in that article, is also very good.

Autoglym Fast Glass is also ideal for removing greasy fingerprints and general smears on all the inside windows. It’s the only product I’ve found which genuinely doesn’t leave streaks or residues when it dries. You can get it from Halfords .


Cleaning The Windscreen – Outside

If you take your car to a drive-thru carwash your windscreen gets coated with wax which smears when the wipers operate. Also, over time you get greasy patches on the outside which only become apparent when it rains. And don’t get me started on bugs and their superglue blood

There are several ways of dealing with these:

    • Astonish Tar & Insect Remover – it gets bug guts off instantly. It also removes wax and grease
    • Clearalex is another option – add this to your wash bottle to prevent grease build up in the first place. The only problem is it leaves streaks if you let it run and then dry
    • Use a 1% solution of sodium lauryl sulphate (SLS) in your wash bottle
    • Use a 5% solution of SLS in a spray bottle to remove bug guts
    • If you live in a hard water area, try using boiled and filtered rain water to prevents trails of lime deposit on your windscreen.

Astonish products can be bought from most car accessory stores, as can Clearalex . Clearalex is also available through sellers on eBay at much better prices. If I’m buying windscreen detergent then I use Carplan concentrate. However, I’ve started to make my own these days (see below).

As an update to this, I have discovered “sugar soap”, which is used in the building and decorating trades for degreasing surfaces prior to painting. You can buy it from most DIY stores and it is very cheap (around £2 for 430g). I think it has a similar composition to Clearalex. It will get even the most stubborn crud off your windscreen. And as a further update, I have discovered Traffic Film Remover – as detailed in this article.


Homemade Wash Bottle Detergent

Commercial products contain a powerful surfactant and an antifreeze agent. One of the most powerful surfactants is called sodium lauryl sulphate (SLS), and ethanol is an excellent antifreeze.

To make 5 litres of screenwash good down to -4°C you need the following:

  • 500g ethanol
  • 20g of 70% SLS
  • Boiled rain water to make 5L

To make the same quantity good down to -15°C you need:

  • 1.5kg ethanol
  • 20g of 70% SLS
  • Boiled rain water to make 5L

You can go halfway with the ethanol for a -10°C screenwash solution.

Both SLS and ethanol can be purchased online. Ethanol costs about £2.40 per litre from various retailers. I buy SLS from Mistral Chemicals in Northern Ireland (5kg of the 70% stuff costs about £30, but it will last you for years).

As an update, I have discovered Traffic Film Remover – as detailed in this article – which I also add to the above recipes at 1-2% instead of SLS.


Homemade Bug Remover

To make 750mls of a powerful bug remover and general degreaser you need:

  • 15g of 70% SLS
  • Boiled rain water to make 750mls

I put this in a spray bottle. In all the above recipes it’s a good idea to heat the water a little to help dissolve the SLS.

As an update, I have discovered Traffic Film Remover – as detailed in this article – which is pretty much the ultimate bug remover.


Tar Or Paint on Bodywork/Alloys

Last year I noticed that I had got a lot of black paint splashes on my alloys on one side of the car. It was also on the side panels and doors. If someone hadn’t thrown paint at the car (and there was too little for me to suspect this), then I must have run over something with paint in it and it had burst, splashing the car.

Astonish Tar & Insect Remover is good for tar, but it won’t touch paint. The solution is to use good old Brasso metal polish. This contains solvents and a mild abrasive and it took the paint on my car off with ease.

Brasso is also good for removing surface scratches.

As an update, I have discovered Traffic Film Remover – as detailed in this article – which seems to remove almost anything.


Frozen Washers

If the water in your washer reservoir freezes it’s because you haven’t got a high enough concentration of detergent/antifreeze in it (if you’ve only got water in then it serves you right!)

Try to avoid the situation first of all by using a high enough concentration of screenwash based on what the label says (or use the recipes above), and listen to what the weathermen are forecasting. I tend to use a summer mix until the first sign of frost, then I go to a winter mix irrespective of what the weather is actually doing.

If you do get caught out, add 500mls of methylated spirits, available from any hardware or decorating store (DON’T use turpentine or turpentine substitute) in the washer reservoir if there’s enough head space. Around 800mls of meths would protect you down to around -9ºC or so, even if you had just water in there. It will gradually defrost any ice which has formed.

Sometimes, it isn’t your reservoir or pipes but the nozzles which have frozen (rain and moisture gets in and freezes, even if you have a good winter mix in the reservoir). In this case you can pour warm water on them (NOT on the windscreen – it could crack) and then quickly try the pump. On the rear one, I often get it working just by holding my thumb on it for about 30 seconds to warm it.


Washer Jets Changing Direction

A build up of limescale or other deposits from the washer reservoir can lead to your washer jets squirting all over the place. It used to drive me mad until I realised the jets weren’t actually moving – it hit me when one time I could hardly find the hole to get the pin in to adjust them (although the car I have now has non-adjustable jets which spray in a wider pattern)!

Use Cillit Bang Lime & Grime. Just a few drops on the nozzles, and after a few minutes your jets will be squirting at full power where they are supposed to.

A longer term solution is to use rain water or the condense from a dehumidifier instead of tap water (if you live in a hard water area). That way, there’s no lime to build up in the first place. Make sure you boil it and filter out any crap first.

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