Rain x v Aquapel

[Neil H]

Hi all,
Not sure if anybody else uses the windscreen waterproofing products mentioned but if you do, I'd be keen to know your thoughts.

I used to use Aquapel when it was sold in Costco (£20 for 6) and I tended to treat my SAAB screen 3 times a year with it. It stood up well to wipers and the elements and was amazing in heavy rain.
I bought some Rainx a few weeks ago and I have to say for me at least, it's been a huge letdown. It's harder to apply, seems to last for maybe 10 days max and is nowhere as effective as Aquapel as far as I can see.

So are there and happy Rain x customers out there? Am I applying it wrong?

 

[drmw]

I've used RainX in the past - and other similar products.

Brilliant in the rain during the day.

Nigh on dangerous in the rain at night

 

[Neil H]

I've used RainX in the past - and other similar products.

Brilliant in the rain during the day.

Nigh on dangerous in the rain at night

Was that because it didn't clear quickly enough? I don't recall any issues at night but it is 3 years ago? The Rain x product just doesn't work as well from my perspective.

 

[drmw]

Was that because it didn't clear quickly enough? I don't recall any issues at night but it is 3 years ago? The Rain x product just doesn't work as well from my perspective.

No (and was the same in my opinion with several products) - rain+wiper+dark+headlights coming the other way = dreadful smearing effect

 

[television]

Do not forget that products like rain X atomize the water too fine for the rain sensor to recognize.

 

[Neil H]

Yes Malc, I noticed that too. From memory, I have used Aquapel on the CLS once and the auto wipers tended to struggle. That said, at motorway speeds I didn't use my wipers at all as the product cleared the screen as if not more effectively.
On balance, I think Aquapel was worthwhile, Rain x doesn't seem to do the job it seems.

 

[C350Carl]

Do not forget that products like rain X atomize the water too fine for the rain sensor to recognize.

I'm not aware of any coating that will atomize or break up the atoms in water. The only way that happens with rain is from the impact of it hitting the screen.

They produce a surface that water can't grip too. Similar to a lotus leaf effect. So the water runs off and doesn't get broken up. That's how a hydrophobic coating works. You can also get hydrophilic coatings but I wouldn't ever recommend that on a car windscreen. Hydrophilic causes the water to rapidly spread and thus evaporates quicker. There were a few trials done a couple of years ago for automotive hydrophilic coatings. But they never caught on as they cause the residue to be left behind. Whereas a hydrophobic coating makes the water stay intact around the minerals it is formed and thus reduces the dirt left behind. This is partly why it is easier to clean a properly detailed car than one that isn't.

I've put screen sealant on loads of cars. I've never had anyone complain about the rain sensor not working properly.

I've had auto wipers on my last four cars over the past few years. I always use screen sealant of one form or another and never ever had an issue with a rain sensor.

I'm not aware of any rain sensor that doesn't work on anything other than light. In that it detects the rain by the light rapidly changing due to water running over it. Hence you can check its function by pouring water over it. But if you pour water anywhere else on the screen the wipers won't work. That's not to say there isn't another way it's detected. I just don't know of any.

Here is a image from GTechniq that shows how the coatings work.

 

[daveenty]

I use THIS STUFF, originally on the advice of one or two detailing forums.

It suits my needs and hardly ever need to use the wipers now. I've certainly not noticed any streaking at nights/low light conditions with it, though I did apply it exactly as per the instructions.

Even used it on the Jeep in the hope that it would prevent freezing up but no luck there unfortunately.

 

[C350Carl]

To the OP you are probably applying it wrong. Or there is something on the screen that is causing it to fail. The screen needs to be immaculately clean to get it to bond properly. When I detail someone's car if they can't tell me the history of the screen it takes me about 2hrs to prepare the screen to have a sealant applied. This involves using wire wool, clay a rayon pad on a rotary and cerium oxide polish. The screen is then cleaned thoroughly with a product called Eraser which removes polishing oils and then a 2 pass clean with neat IPA. Only then do I apply the sealant.

Rain X should last around 3-4 weeks when applied and cured properly.

I see a lot of people complain about performance. The other thing to bear in mind is the rake of the windscreen and the drag coefficient of the car. Apply a sealant to a RangeRover and it will perform really well due to having a near upright screen. Apply the same sealant to a CLS and it will perform differently due to the rake of the screen and drag coefficient being better. So it will appear to be less affective.

They are also subject to the wiper use so if you do a lot of round town driving you may feel it's not great. But get up to motorway speeds and you will hardly need to use your wipers. But using wipers will eventually wear the coatings off.

Some coatings claim up to a 2yr life. But not on a daily driver they won't. I currently use Nanolex Ultra which claims up to 18months. The most I have had is 10mths before it started to fail and was completely gone after 12mths.

If you are near to Folkestone I can teach you how to apply the coatings properly regardless of which you decide to use.

 

[Neil H]

Hi Carl,
From memory the droplets do seem to break down on contact from the usual raindrop size to lots of tiny droplets, I think that is what Malc means though I'm not sure atomised is the right term, that said, I knew instantly what he was talking about.
I also find that the windscreen wipers don't cut in on automatic as quickly as usual, it's not an issue over 40 but at low speed, perhaps the effect I described doesn't cut in to the light sensor.
In any case, I've found a source and got some on order. I don't think I've ever been so well prepared for winter so we can expect no snow!

 

[C350Carl]

I use THIS STUFF, originally on the advice of one or two detailing forums.



It suits my needs and hardly ever need to use the wipers now. I've certainly not noticed any streaking at nights/low light conditions with it, though I did apply it exactly as per the instructions.



Even used it on the Jeep in the hope that it would prevent freezing up but no luck there unfortunately.

Carlack is very good and I used to use it.

My current favourite though is Nanolex Ultra. But I do a lot of motorway miles.

 

[television]

I'm not aware of any coating that will atomize or break up the atoms in water. The only way that happens with rain is from the impact of it hitting the screen.

They produce a surface that water can't grip too. Similar to a lotus leaf effect. So the water runs off and doesn't get broken up. That's how a hydrophobic coating works. You can also get hydrophilic coatings but I wouldn't ever recommend that on a car windscreen. Hydrophilic causes the water to rapidly spread and thus evaporates quicker. There were a few trials done a couple of years ago for automotive hydrophilic coatings. But they never caught on as they cause the residue to be left behind. Whereas a hydrophobic coating makes the water stay intact around the minerals it is formed and thus reduces the dirt left behind. This is partly why it is easier to clean a properly detailed car than one that isn't.

I've put screen sealant on loads of cars. I've never had anyone complain about the rain sensor not working properly.

I've had auto wipers on my last four cars over the past few years. I always use screen sealant of one form or another and never ever had an issue with a rain sensor.

I'm not aware of any rain sensor that doesn't work on anything other than light. In that it detects the rain by the light rapidly changing due to water running over it. Hence you can check its function by pouring water over it. But if you pour water anywhere else on the screen the wipers won't work. That's not to say there isn't another way it's detected. I just don't know of any.

Here is a image from GTechniq that shows how the coatings work.

Mercedes have this warning in WIS and possibly some hand books.

Works on light is not really correct, it works on a beam sent through a prism, when the screen is dry the the sensor receiving the beam is operating normally, if a large enough rain drop falls in the prism area, then the received beam goes out of focus, and the current in that circuit drops, it is this action that starts the wipers. I would imagine that over the years since it was first introduced this system could be more refined. It was first used on the S class about 1996 onwards.

 

[C350Carl]

Hi Carl,
From memory the droplets do seem to break down on contact from the usual raindrop size to lots of tiny droplets, I think that is what Malc means though I'm not sure atomised is the right term, that said, I knew instantly what he was talking about.
I also find that the windscreen wipers don't cut in on automatic as quickly as usual, it's not an issue over 40 but at low speed, perhaps the effect I described doesn't cut in to the light sensor.
In any case, I've found a source and got some on order. I don't think I've ever been so well prepared for winter so we can expect no snow!í*½í¸‰

The water isn't behaving any different to what it normally does. All that is happening now is the coating is stopping the water from spreading and the impact is causing the water to break up around different minerals contained inside it.

You're the first person I've ever heard say their rain sensor is now less effective. Please don't take that as me saying you're lying or wrong as I'm not. I've been detailing cars for a few years now and have just never heard of it.

Is the screen clean? I know that none of the coatings work very well on fine mist etc if the car has a good raked screen. I would get some glass cleaner (autoglym fast glass is ok and can be bought in Halfrauds) and a proper glass cleaning cloth. Normal microfibre cloths don't work as well as proper glass cloths. Give the screen a good clean with those and see how you get on.

Like I said if you're near Folkestone give me a shout and I'll help you out if I can .

 

[Neil H]

Perhaps the screen isn't that clean. I'll follow your advice on the cleaning routine. Maybe the break up is an optical illusion but I definitely have that impression and Malcs description was bang on.
Sadly I'm 300 miles away from you so I can't bring it in but defer to your knowledge as you obviously know a heck of a lot more than me.
Thanks for the tip!

 

[C350Carl]

Mercedes have this warning in WIS and possibly some hand books.



Works on light is not really correct, it works on a beam sent through a prism, when the screen is dry the the sensor receiving the beam is operating normally, if a large enough rain drop falls in the prism area, then the received beam goes out of focus, and the current in that circuit drops, it is this action that starts the wipers. I would imagine that over the years since it was first introduced this system could be more refined. It was first used on the S class about 1996 onwards.

I've no doubt that there will be some warning somewhere about them. I suppose it's like anything if they're not used correctly then they could cause issues.

I've just never heard of anyone having an issue until Neil has just said it.

I've heard people complain one coating is worse than another etc. But a lot of time that is down to poor application, preparation or not understanding what the coatings do.

I knew the sensor was something to do with light. Never knew about the prism bit though. So thank you. I've learnt something new today. Everyday a school day as they say. That's a genuine comment by the way and not me being sarcastic.

 

[C350Carl]

Perhaps the screen isn't that clean. I'll follow your advice on the cleaning routine. Maybe the break up is an optical illusion but I definitely have that impression and Malcs description was bang on.
Sadly I'm 300 miles away from you so I can't bring it in but defer to your knowledge as you obviously know a heck of a lot more than me.
Thanks for the tip!

Send me a PM later this week to jog my memory as I'm in work but I can write you a little tutorial for cleaning and preparing the screen.

As long as you don't mind using a bit of elbow grease and little bit of expenditure then you can prepare and treat the screen.

If I get time later today I'll do it but I'm fairly busy this afternoon/evening.

 

[television]

I've no doubt that there will be some warning somewhere about them. I suppose it's like anything if they're not used correctly then they could cause issues.

I've just never heard of anyone having an issue until Neil has just said it.

I've heard people complain one coating is worse than another etc. But a lot of time that is down to poor application, preparation or not understanding what the coatings do.

I knew the sensor was something to do with light. Never knew about the prism bit though. So thank you. I've learnt something new today. Everyday a school day as they say. That's a genuine comment by the way and not me being sarcastic.

Thanks, it nice to pass on something when one can. the prism bit is the reason why the wipers if left in the auto mode will give one sweep when going round a corner or going into sun light.

I learn something as well here, do I try some of these newer clean screen products, the auto wiper on my old CL work 100 better than on my newer one.

Its just so nice to be able to discuss things in a nice polite way

Thank you.

 

[C350Carl]

Yup. Makes a change as some forums I've been on people start becoming Google experts and Keyboard warriors!

To be honest if you're happy with how everything works now I wouldn't change what you do.

I only constantly change so that I can find the "latest best" techniques so when a customer asks i can give them good advice. Rather than give them a companies "preferred" advice to make money from them.

The newer CL function could be due to a different rake in the screen. If the older CL has a more upright screen then water will move round on it more quickly than the newer one.

Have you owned the newer CL since it was new? Or are you the second owner? If so how long have you had it?

Reason I ask is if you are the second owner the previous one could have applied a coating that you aren't aware of and could be making it function incorrectly if Neil's post is anything to go by. But generally a clean with glass cleaner and a cloth will usually clear up any issues of dirt etc.

Is the sensor in the CL within the sweep of the wipers?

 

[drmw]

I tried something different to clean my screen last weekend to really good effect. I had a new conservatory roof fitted a few months back and the guys had a liquid that cleaned the PVC incredibly well (even removed old silicon sealant). I asked where to buy it - they left me a bottle.

It's some form of uPVC solvent and I've never seen anything so effective at removing grease, so after washing the car I used some of this on a paper towel and really scrubbed the windscreen.

I've always thought that conventional window cleaners leave a residue either by accident or design - the result with this is stunning - no residue and sparkling clear.

It's about £5/litre to Joe Public

 

[C350Carl]

I tried something different to clean my screen last weekend to really good effect. I had a new conservatory roof fitted a few months back and the guys had a liquid that cleaned the PVC incredibly well (even removed old silicon sealant). I asked where to buy it - they left me a bottle.



It's some form of uPVC solvent and I've never seen anything so effective at removing grease, so after washing the car I used some of this on a paper towel and really scrubbed the windscreen.



I've always thought that conventional window cleaners leave a residue either by accident or design - the result with this is stunning - no residue and sparkling clear.



It's about £5/litre to Joe Public

It will probably be an IPA solution.

I make my own glass cleaner with it. Buy a 5litre tub in bulk and then make up as required with distilled water into a spray bottle. 1 part IPA to 3 Parts water makes a decent cleaner. I increase the ratio to 50-50 for winter though to cut through road grime and salt a lot better.