Use PTFE Thread Sealing Tape on Flashlights?

I know there has been many threads of CPF discussing which silicone grease to use on the threads of the expensive flashlights. However, I have never heard anyone mention using plumber's thread sealing tape instead of silicone grease.

I currently use RyeMetal Hydroseal Thread Lube. It works great, however it does get messy over time because it is a paste. I got the idea the other day when I replaced the shower head in the bathroom, my dad told me to use Dorf PTFE Thread Sealing Tape on the threads to make it waterproof and easier to tighten the head.

I want to ask if anyone else uses any sort of plumber's thread tape on their flashlights and if it will ruin the threads on my aluminium (Inova X5t) or nitrolon (SF G2) flashlights.

Regards
Jeff

I used dry lube on a maglite once. In that case it was molybdenum sulfide. The aluminum parts (tail cap & body) ended up welded together. And I do mean welded, they had to be cut apart, the aluminum would tear before it would break loose. So don't use moly sulfide on aluminum. But I think you would be OK with teflon, especially the tape, it's supposed to be inert.

I mention this in case someone might try a dry lube with more than teflon as an ingrediant. I found a mini maglite in my Y2K bug out bag the other day, and it had frozen threads. Two pair of pliers got it apart fairly easily. It had had petroleum jelly on it, but I guess even that can't last 3-4 years. The lithium batteries were still good. I think I'll try the teflon tape myself, on a minimag, and see how it is after a year. -RussH

I've used it on lights. Not so much to lube, but to "tighten" loose threads a bit. It certainly will seal out water. Not messy too.

PTFE tape helps you make leak-proof threaded connections at least partially because it reduces the friction of the threads rubbing against one another so much that you can tighten the threads MORE, thereby jamming the threads against one another and sealing them. This process works pretty well with plumbing threads, because those are tapered threads.

Regular threads (nuts, bolts, flashlights, etc) generally have straight threads. In that case, PTFE tape will still reduce the thread friction and allow you to tighten those threads pretty tight.

Be CAREFUL if you use PTFE tape with plastic threads! You can usually tighten the pieces so much that you will break the plastic. /ubbthreads/images/graemlins/frown.gif

Properly machined parts with an o-ring seal don't need any PTFE tape to seal out liquids. A small amount of silicone grease on the threads to allow them to turn easily is usually all you need. /ubbthreads/images/graemlins/grin.gif

Will the PTFE tape hurt the threads? Nope, but you might by overtightening them. /ubbthreads/images/graemlins/icon15.gif

Be careful using PIFE tape...you could wind up electically isolating body parts that need a conductive connection. AA MiniMags come to mind...isolate the tne tail cap and you cut the negative path to the bulb!

I too have mostly used PTFE tape on lights, basically to stop head wobble and it's disasterous beam screwing!

I use the heck out of it in my line of work!

[ QUOTE ]
Roy said:
Be careful using PIFE tape...you could wind up electically isolating body parts that need a conductive connection. AA MiniMags come to mind...isolate the tne tail cap and you cut the negative path to the bulb!

[/ QUOTE ]
But with a MiniMag, if you have a clickie tail switch, you might want the head to be tight, so you don't have to keep focusing it, and it can be electrically insulated from the body. I didn't have any plumbing tape handy, so I used the plastic from a sandwich bag to screw the head on tight. That works quite well.

Hmmm... thanks for the replies.
All the flashlights I have (not many... yet) won't have the circuit broken by the tape, so I can use the tape on them.
MoonRise: You warned about damaging plastic threads by overtightening. By using the word "plastic", I assume you're talking about regular plastic, not quality indestructable nitrolon /ubbthreads/images/graemlins/smile.gif
After considering everyone's opinions, I've decided that it is safe to try PTFE or teflon tape on the threads.
Now I have to go to the hardware store to get a new roll of it.
I will post results if I remember.

Jeff

[ QUOTE ]
i7r7 said:

MoonRise: You warned about damaging plastic threads by overtightening. By using the word "plastic", I assume you're talking about regular plastic, not quality indestructable nitrolon /ubbthreads/images/graemlins/smile.gif ...
Jeff

[/ QUOTE ]

Indestructable?? Ha, -NOTHING- is indestructable. /ubbthreads/images/graemlins/naughty.gif

Bigger hammer, bigger wrench, cheater bar on the end of the wrench, power tools, torches (the ones with flames or electrodes or plasma), explosives, etc. Nothing is indestructable. /ubbthreads/images/graemlins/sssh.gif

Just be gentle when you tighten threaded parts if you have PTFE tape on the threads. The friction reduction can be drastic, so you torque the threads to where you are used to and suddenly parts break or jam. /ubbthreads/images/graemlins/ohgeez.gif

Hmmm... I just tried using the tape on both my SF G2 and Inova X5.
On the X5, after a few times tightening and removing the tailcap, the tape all got squashed at the end of the thread (near the O ring). I only put one layer of tape, however, it still seemed to be too thick to fit between the 2 sets of threads.

On the "not so indestructable" nitrolon, it worked pretty well for a while, until it started to tear where the tape was too thin, the it started to stick together in lumps.

In both cases, I had to remove the tape because it was making it hard for the tailcaps to turn.

I don't know about the rest of you, but the tape didn't work so well on frequently used threads. I guess it doesn't help that I'm using a roll of tape which is probably over 10 years old /ubbthreads/images/graemlins/ooo.gif

I changed everything back to the good old silicone grease... i noticed that after I removed the tape, it took all the old silcone grease with it.

Jeff

Yah, PTFE tape isn't meant for use on threads that are used. It's just meant for use on initial assembly. Repeated tightening and loosening of the threads makes the tape ball-up, etc.

The tape will tear and get stringy in between the threads in a normal installation. Hey, it's geting -cut- by the threads. The age of the tape doesn't really make a difference.

Use the silicon grease.