I have read many times that Vasoline (petroleum jelly) isn't good to use as a sealant/lubricant for flashlights because it deteriorates the rubber o rings. Is that true, or is it just another myth?I've done it with my Mag Lights when working over the years and have never had a problem with deteriorated o rings, but then just because it hasn't happened to me doesn't mean that it won't happen.Def
I use NyoGel 759G because it is one of the lubes that SureFire use. I got a 1lb pot of it a couple years ago. I've still got about 1/3 left."This gel type grease is mildly thixotropic i.e. it becomes semi-fluid on agitation, improving lubrication of the seal surfaces, but it returns to the gelled state when agitation ceases. The grease has excellent stay-in-place characteristics so it steadily provides free motion & water resistance."[I had this description on file without a source, sorry]
if your lubing surefire lights, Surefire doesnt recommend the use of any petroleum based lubricants as it causes the o-rings to swell
Hi, I struggled with this question about a year ago. Vaseline gums and sticks after a while and is said to degrade rubber seals. Liquid lubricants tend to collect dirt and migrate into flashlight internals.The manual for my Princeton Tecs said "use silicone-based grease and no other." After a bit of digging on the Web, I discovered that polydimethylsiloxane is the stuff you need.After poking around a bit, I discovered this it's available at any automotive store under the name "dielectric tune-up grease." It seems to work fine for "above water" flashlights, and it doesn't gum up over time. Got a lifetime supply at Cdn. Tire for under ten bucks.A caution, though: I don't know the purity of this stuff. If I was relying on a diving light for life-and-limb, I'd pay the boutique price from the dive shop.
I don't think that natural rubber o-rings have been made in many years - they have all been made of synthetic rubbers for many years.Don't worry about the lube damaging the o-ring - use whatever lubricant gives the 'feel' you prefer. BTW, silicone greases tend to creep forever and attract dust like crazy, without actually being good lubricants.I find that a light grease works nicely and minimizes the amount that gets into the works, unlike an oil which can migrate around the inside of the light.