Need help with condensation issue. My Ultrafire 502B and Uniquefire UF-T20 both form condensation under the lens after a short period of use.
Why does this happen and is there a remedy? These are both new lights.
Thanks
It sounds like the lights were assembled in a humid location, I’m assuming its pretty cold where you are right now?
I’d strip them inside, somewhere warm, let everything warm up to room temperature then reassemble.
I’ve read of people having the same issue in England as we have a damp climate.
True, but I assume most in the states have air con? Air con should remove most of the humidity from the air so the light should dry out.
I find it still happens on lights over 3 watts with a 30mm+ lense even if you do it in humidity of around 40%. It only shows in cold weather though, more so if there’s airflow onto the lense e.g. when running. It’s pretty hard to stop.
The only relative success I’ve had is with removable bezels. I loosen it, turn it on until it’s hot to touch, lift the lense a mm or two, count to 20 and close it up again. That normally helps.
I think it was you I was thinking of red tbh.
install one of those do not eat packets
I dont have these problems. My lights run very hot. :D
I will disassemble both lights and let them dry out for a day or two before I reassemble. Thanks for the good advice. 
I know this is totally over the top, but I assemble most of my lights at work under the nitrogen hood on the selective-solder machine Nitrogen carries no humidity, so there is no such thing as condensation
PPtk
doesn’t the nitrogen disappear as soon as you open the tailcap to replace the battery?
Put some uncooked rice in the battery compartment and leave it in the sun a couple of hours.
Yep, and if I’ve changed the battery recently, then the next time I’m at work, I just re nitrogenize it
Funny how i can’t get nitrogen for my tires to lengthen rubber life yet you use it for something none of the rest of us would consider.
Hm, interesting, didn’t knew that. I would recommend take whole flashlight apart and use hair dryer. That will dry all parts in just few minutes.
Rise and that silicon stuff could work as well. BTW, when that silicon “do not eat” stuff is “full” and will not suck more moisure? How can you distinguish a new from used?
Most of my lights fog up when I get them during the winter. After being hauled around in freezing trailers, cold postal trucks and an equally cold mailbox, entering a warm atmosphere just steams them Up. Usually their okay after being acclimatized, but if it seems like there is a lot of moisture I’ll take them apart and place the head bezel down on a warm radiator for a couple of days.
Attn. Scaru. The radiator trick is also great for torches that have gone through a wash cycle.
I would, but I ate all of mine. :party:
what the hell did you do that for, they are meant to be rationed for use when you are lost in the middle of the ocean with no water to drink
lol, quite sure he was kidding :bigsmile: … or not 
[quote=Bort]
I always carry a can of dehydrated water just in case that happens…
[quote=texaspyro]
you have to careful with those to avoid dihydrogen monoxide poisoning