By on November 25, 2009

(courtesy: Dennis Forbes/Flickr)

TTAC Commentator Riz writes:

I’ve just got my first “commuter” car – 2009 Civic DX-G and I’ve been surprised at the amount of dew on all the windows most mornings and how much ‘crud’ dries on after rain. Compared to any of the cars/minivans we’ve owned or our current family driver (’06 Mazda 5) it’s really annoying. And it’s not just the front / back (although the lack of rear wiper is lamentable) – side windows are also an issue. So what’s the ideal product – RainX or another brand? And any concerns for application (like don’t get any on the non painted side mirror covers or that sort of thing)? And how long does it last? Note – this product needs to also deal with frost and snow as I live in Calgary.

Also – is this common on Honda’s? We’re looking at a new minivan next year, and if the Odyssey is more likely to do this than the Sienna then I’d like to plan for it.

Sajeev answers:

For those without a garage or carport, dew ( is something you simply put up with. I’ve used three products to minimize the effects of condensation on your morning drive to work: glass cleaner, automotive wax, and sandpaper. Rain X (or equivalent) is always a good idea for the windscreen, but check out my additional ideas.

Glass cleaner: clean the inside of your car regularly, using a cleaner designed for automotive applications for the best results. Temperature differentials cause fogging on the inside face of glass, which really sticks to the thin film of grease, oil and smoke residue (if you smoke) already on there. Remove the contaminants and you’ll have a far better driving experience as your HVAC’s defroster works its magic.

Wax: Oh, I’m gonna take some flack for this: whenever you wax, apply it to the side and rear windows (not the windshield, that makes the wipers streak) using the same procedure used with painted surfaces. Not only does wax leave a slick finish to keep water and “crud” off the glass, it keeps you from needing another product that collects dust in the tool shed.

Sandpaper: take a piece (about the size of your thumbprint) of 800-ish grit sandpaper and fold it in half. Place the folded paper over the rubber portion of your wiper blade, then hold it between your thumb and index finger. Move your fingers up and down the blade several times and then wash it with soap and water to remove the old rubber. Congratulations, you’ve now fixed a streaky wiper. And effectively doubled or tripled its lifespan.

Granted, your vehicles (the Aerostar-looking Civic and your Minivans) mean you have a lot of real estate to cover, but that’s the price you pay for your love of Hondas and your need to carry a family. Hopefully this will help manage your condensation problem, and makes your morning commute less irritating.

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22 Comments on “Piston Slap: Do The Dew?...”

  • avatar

    I simply use paper towels on the wiper blades in the manner you describe. Or newspaper. It works great.
    Streaks often result from little bits of stuff (pieces of leaves mostly, where I live, but in spring, seeds or maybe pollen) sticking to the windshield wiper blade.
    I do not notice excessive dew with my Honda, which is parked outside in Massachusetts (not nearly as cold, probably not as dry as Calgary.

    • 0 avatar

      I’ve also found that cleaning the inside and outside of the windows with newspaper works like a charm.  And the harsh paper towels that most gas stations provide near their pumps do a nice job on the wiper blades in a pinch.

      And, yes, in my experience, Honda’s do seem to have more issues with condensation (inside) and dew (outside) than other brands I’ve owned.  No idea why, though.  I used to hate getting in my Civic and my CRX during upstate NY winters and finding the condensation frozen to the windshield.  You shouldn’t have to use an ice scrapper inside your car…

  • avatar

    IMO, just get a bottle of this and go nuts on all your glass on your car:
    I’ve used that stuff for years, and it can be applied to all surfaces on your car.  Of course you do have to buff off the excess, but you can put it on your windshield as well with fantastic results.  I haven’t changed my wipers in 40,000 miles because water just won’t sit on the front windshield when the car is moving.
    Also, just get one of these things and squeege your car windshield in the moring.  It takes 15 seconds.

  • avatar

    YMMV but I hate RainX.  Just seems to smear in light rain.

    • 0 avatar

      I found that Aquapel works better than Rain-X, and lasts a lot longer. I used to have to buy it large bulk packages, sold to detailers or auto glass shops, but now Aquapel has a consumer package for their product.
      If you search on line, you’ll find several enthusiast detail supply houses, like Autogeek, that carry it. Be advised this is not a bottled product, like Rain-X. It’s an single applicator based product, and all the glass needs to be preped first with proper cleaning. Once the applicator is activated, you have right there and then to apply it, or the applicator will dry out. There is no way to save the applicator for later if you make a mistake.
      That said, it works far better than Rain-x (no smearing) and lasts three times or more longer.

  • avatar
    bumpy ii

    I just hit it with one of those squeegee/ice scraper things in the morning while the car warms up.

  • avatar

    Sajeev’s suggestion to thoroughly clean your interior windows is spot-on… or would that be spot-off?  Dew and water vapor forms much more readily on dirt, oils and other residue than it does to clean glass.  And the more water is there, the longer it will take your defroster to dry it off.
    Even if you keep your car in spotless condition and don’t smoke, you’d be surprised how much crud gets adhered to your interior glass.  My guess is that off-gassing interior components are responsible for a lot of it.  I once owned a Toyota that was absolutely miserable in this respect, I had to clean oily gunk off of the inside of the windshield every few weeks.
    Another tip: Don’t wipe dew off of windows with your bare hands!  Easy to say when you can’t see and need to get where you’re going, but you’ll coat your windows with oils and compound the problem tenfold, even if your hands are clean.  I carry a terry cloth towel under my seat for when I need to dry off my windows in a hurry, but usually I avoid using even that and let the defroster do its work.  Every time I’ve used my hands, I’ve ended up regretting it.  Keep yer mitts off the glass!
    I’d also suggest using several paper towels as you clean.  I usually make one pass with my first towel, then grab a clean one for a second pass.  This helps to avoid spreading the gunk and oils around and prevents streaking.
    One more thing: if you regularly get lots of water vapor forming on the inside of your windows, I would do a thorough check for leaks.  A wet trunk, waterlogged carpet or puddle on the floor will can really cause a lot of problems in this respect… the water has to come from somewhere before it collects on the window.

    • 0 avatar

      To your comments on the second paragraph: I’ve heard that leather interiors are even worse about this.  The natural oils (or the finishing stuff on top of the leather) tends to gas up and cake on windows when exposed to sunlight.  I don’t have any proof of that, just throwing it out there.

    • 0 avatar

      My 1960 220S sedan was particularly bad for this. I suspect some product used by a previous owner, as my old 230SL didn’t have the problem nor did other 60’s Mercedes cars whose owners I talked to.

    • 0 avatar

      Sajeev, you may be on to something. My current truck is nearly identical to my old one (2002 and 2008 Chevy TrailBlazers FYI) with the exception that the new one has leather. The interior glass rarely fogged up in the old one, while the new one seems to do it with the slightest dip in temperature or increase in humidity. I also have no science to back this up, but it makes sense to me anyway.

  • avatar

    Living just north of you in Edmonton, we experience the same morning condensation between May and October (the months when it doesn’t freeze into frost). It happens because night temperatures are low enough to hit the dew point, and metal and glass are the first to lose their latent heat.
    Try changing where you park. The closer you are to a building or tree, the less likely your car will radiant it’s heat away at night. You’ll notice that when it’s cold enough for frost, the side of the car facing a building is frost free.

  • avatar

    I’ve noticed that the more horizontal the window is (like a late model Honda Civic), the worse the dew and frost formation is.  This is because dew and frost can form above the vehicle and then fall on to it.  Trade it for a Ford Model A or get a squeegee.

  • avatar

    RainX is a fine product for rainy or snowy conditions, but seems to have little effect on the overnight dew phenomenon. I second the squeegee suggestion. However, if any of your condensation issues are on the inside surfaces: do NOT use FogX. Worst stuff ever – more like FogXXL. Took half a can of Stoner to make it go away.

  • avatar

    Thanks all for the comments – I was hoping to avoid getting a squeegee and just coat it with something (I’ve been toweling it off so far to minimize streaking).  Knowing what to avoid (like FogX) is critical.  Inside condensation hasn’t been an issue so far, just the dew.

  • avatar

    PPG Aquapel.  Not sure how it works with dew, but with rain it is the best.

  • avatar

    I live two blocks from the ocean in San Diego, and have the same problem with morning fog in Spring and Fall. The entire car is soaked, but I use a squeegee on all the windows. The windshield and back window quickly fog up again, but I can at least use the wipers to clear the windshield.
    I’ve tried everything on the back window, and found only a half solution: a bar of hard Ivory Soap. When the glass is clean and dry, I smear the hard soap over it and spread it evenly with a dry cloth.  The glass will be wet and not exactly clear, but the view is better than a fogged up back window.  I got the idea when I left a dab of soap on the bathroom mirror, and the spot didn’t fog up after  a shower. The Ivory lasts up to a week if it doesn’t rain.

  • avatar

    Another solution:  A remote car starter.  I commute to the railroad station, and the extra time used to wait for the windows to clear come right out of my sleep time if I am going to make my train.  I leave the HVAC system on defrost and start the car 15 minutes before I leave.  To get the rear window defroster to work (mine has a momentary contact switch to engage the defroster) took some clever but simple engineering.  Most remote starters have a relay block with extra relays.  This is what turns the parking lights on and beeps the horn.  I had no use for beeping the horn, but the momentary contact for the remote starter horn relay was just the ticket for emulating the input from the rear defrost switch.  I just tapped into the wire that closes the factory rear defrost relay and let the momentary horn relay provide the “engage” signal to turn on the rear defroster grid.  I have no problem with morning vision!!  Yes there is extra gas used but what price for sleep?  Car seems no worse from whatever added wear that may occur, and the car (Sable) turns 18 one month from now.   All that is left to do is set up some kind of cell phone connection so I can start the car from my cell when I am on the train.  There have been times in the winter where ice has frozen the doors on dozens of cars during the day…

  • avatar
    Daniel J. Stern

    My car wouldn’t accept a remote starter even if I believed in them, which I do not. I’m keen to try out the company’s anti-fog film for glass. Their main marketing emphasis is towards grocery store see-thru freezer doors, but several times it’s mentioned that it’s optically clear and suitable for auto glass. One annoyance when driving an older car in spring, winter, or autumn is the tendency of the defogger not to be able to cope with the amount of fog that forms on the glass. Looks like any good window tinting shop ought to be able to install this stuff. It’s on my list, but the list is longer than the wallet is fat, alas…

  • avatar

    Hey Alberta folks. I keep my Scooby very clean and wax. None of these problems arise for me. Then again all we do up here in McMurray is scrape the outside glass to get the frost off. Keeping the glass clean on the inside must help cause I have never had a problem with dew or frost on the inside.

  • avatar

    I just lower the window and then raise it. The rubber weather strip does the rest.

  • avatar

    golden2husky: I think the iPhone has an app for that. I remeber seeing something about it online.

  • avatar

    This was more for the outside, so film isn’t all that useful.  And rolling down the window doesn’t work for the back glass.  Oddly enough the stripping on either side window doesn’t provide enough contact to wipe down the window – tried that first day.  I’ll check into the Aquapel stuff, though.

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