How do I prevent windshield fogging?

[matthewmiller01]

As I was cruising the other week (at ~7:30 in the morning) to get the boat hauled out for a trim sender replacement, the windshield fogged up (it was in the 40s out). The obvious question is how do I prevent it from doing so (I haven't tried Rain-X anti-fog yet)? Does anyone have any tips, once it has fogged up, on how I can clear it, sans wiping it with a towel or using a hair dryer? I don't have any ventilation in the cockpit to be able to redirect toward the windshield.

What do you guys do or use? I did have the heat on in the cabin with the door open, hoping that would prevent it, but that obviously didn't work.

 

[mwph]

Any chance having the heat on in order to prevent it actually caused it?

Ive always operated under the guides that a difference (between inside & outside) in temp and or humidity causes fogging.

 

[northern]

We have upper and lower helms. Upper helm is fully enclosed. We have heat ducted to the windshields on both helms and it keeps them fog free even in cold 50F rain. Not sure of type but got 40000BTU for each helm that get heat out of engine anti freeze. Looked up heaters and Heater Craft came up Looks similar to what I have. I got some one to put them in as it looked like a lot of crawling and reaching and fitting. Upper helm has 3 ducts lower helm has 4. I put one on the dash the others through out the cabin. All duct outlets have flappers on them so you can turn them off or direct the air. You can turn all but the one to windshield off to increase air flow. If I was to doit again I would put 2 ducts th the windshield area.
http://www.heatercraft.com/polaris-ranger-xp-800cc-heater-defroster-kit-2009-2010/
PM me if you need details on how it all goes in. The Heater Craft unit has to go below the highest point of the heat exchangers on your engine.

 

[Lucky's]

The cheap, easy solution is the rain x anti fog. I have used it and it works fairly well. Certainly an improvement over nothing.


Shaun
Sent from my iPhone

 

[Bob & Sue]

Heater Craft is what we have in our boat with 2 outlets in the helm one for defogging one at my feet two in the cabin they are fairly easy to install never have a problem with fogging even on rainy fog days.

http://www.fisheriessupply.com/heater-craft

 

[rcknecht]

My 300 DA had a built in Defoger and cockpit heat, that work well. What I do now is us a towel... I found that Rainex doesn't work well for the fog and condensation inside the cockpit... A towell works well...

 

[Lazy Daze]

I have a small, 12v fan that has a suction cup mount. It's one of those cageless, soft-bladed thing-a-ma-bobs that is advertised as "finger safe". It hurts a tiny bit, but my 8-year old boy thinks it's the funniest thing in the world when he sticks his finger (and sometimes his tongue) in it...... over and over and over again. Reminds me of that saying -- "You can't fix stupid".