I learned the hard way. Up to the BWCA last weekend and mosquitoes were of moderate abundance so I thought I would fool them. I sprayed a little DEET(close to 100% DEET)on the vestibule by the door on my eureka timberline. Did it help keep the mosquitoes away. Yes I think it helped. But a hour later I looked at my tent and it was staying very wet and I could see thru the tent fabric a little and it was sticky on both sides. Well how could that be,its waterproof. Tried wiping it off and really couldn't do much. Got home the next day and washed that area and sun dried it.Got rid of much of the sticky feeling but now that area was not waterproof and very porous.I melted the waterproof coating off and not sure what it did to the nylon mesh. I used some camp dry and hoped that it is waterproof again and also hope I did not weaken that area. Did a little research and DEET WILL MELT SYNTHETICS so be careful. Could it spot or melt plastic lens in glasses? I don't know and don't want to find out. Yes I will still use DEET but watch where I apply it. Another source.

http://sectionhiker.com/deet-dissolves-breathable-fabrics-experimental-results/

DEET will attack any kind of plastics. I know I've messed up cheap watch crystals & eyeglasses with it when I was a kid. I don't know how many pair of socks have had the elastic blown out of them from applying Off while I was out disc golfing.

Sucks you had to find out the hard way on your tent.

i think there is a warning about that on the label.

It also is harmful to plastic. If you have a watch that has any plastic in it like a Timex Expedition and it gets sprayed with the stuff, time for a new watch. I take off my plastic glasses when I spray my head area.

Don't put it on your raingear!

I may have missed the warning,but did not see it on my bottle of spray.

100% DEET on your hands doesn't go well with a steering wheel either! We found that out the hard way about 5 years ago in the BW. The steering wheel is still sticky!

Pinetree - I'm happy to learn from you mistake. I'll think twice about where and how I apply spray.

I see some sites list it as a solvent

lovely. I'm using a solvent to keep the bugs away. just lovely.

quote northallen: "Pinetree - I'm happy to learn from you mistake. I'll think twice about where and how I apply spray."

Amen - I'm thankful to have read these very useful posts!

A few years ago I was fishing in the back of a friends brand new Crestliner Fish and Ski boat. Stable flys were biting my feet so I pump spayed them from the hip with DEET and missed. The DEET ate the paint right off the boat and the owner was heartbroken about it getting damaged so soon. Crap happens. The blistered paint is still there and we never talk about it.

They say it won't harm your liver though.

quote Kevlar: "Don't put it on your raingear!"

Unfortunately, I did, a few years back. I now have a rain jacket with an interesting design :)

The Chicago Tribune had these 2 articals on line today

DEET repels bugs, worries consumers
DEET is the go-to bug repellent, but it does have its drawbacks

All I gotta say about the stuff is...

Also, this and other greasy stuff will smudge your waterproof maps. I have a couple with slight smudges on them due to DEET lotion still on my fingers.

AHA! That's what happened to my glasses. I got a wierd bubble in my glasses last year. Must have got OFF on the lens.

That stuff can be dangerous. The screen on my step-fathers depthfinder was ruined a few years back after getting Deet on it. I use this as an alternative for direct contact with skin.

Repel Eucalyptus

Still use Deet sometimes, just sparingly. Never on bare skin.

quote jjjds1999: "100% DEET on your hands doesn't go well with a steering wheel either! We found that out the hard way about 5 years ago in the BW. The steering wheel is still sticky!"

Doesn't do much for the plastic trim on the interior door handle either.

old post-just a reminder deet has its purpose and I use it often. Just tried in the wrong places at times. Like the plastic on my watch cover and melting waterproofing on my tent. It devours plastic.

Savage Voyageur: "It also is harmful to plastic. If you have a watch that has any plastic in it like a Timex Expedition and it gets sprayed with the stuff, time for a new watch. I take off my plastic glasses when I spray my head area. "

Been there and done that on that type of watch. Still useable, just a little cloudy.

Pinetree: "old post-just a reminder deet has its purpose and I use it often. Just tried in the wrong places at times. Like the plastic on my watch cover and melting waterproofing on my tent. It devours plastic."

I keep a tiny bottle of Ben's capped and in a bag in case of emergency, but Thermacell and permethrin has all I have ever needed. Deet is nasty stuff. Scares me to think how much money I could spend having to replace gear that it destroys should it leak or be sprayed on something it shouldn't by a fellow camp member. Which is why I never take it out of the bag for others to see.

30 percent DEET is the maximum needed to repel the buggers. It doesn't stink like 100 percent and it is a lot less damaging to plastic surfaces. Using 100 percent DEET is like putting high octane gas in your family sedan - it doesn't add any power and costs a lot more. Thus ends the righteous homily for the day.