Silicone grease recommendation

Which brand is best suited for flashlight O rings? Those that is least corrosive to rubber. Can I just use any silicone grease purchase from any DIY stores? I read that some grease contains compuound that degrade rubber and not suited for O rings.

Hoya,
Never crossed my mind. I just bought whatever silicone grease the store had, and used that. So far, no problems with it (I used it on my PM6, my SFs still don't look like they need greasing).

-Omega

I've been using rat shak brand w/no problems

something wrong with vasoline. It is a petroleum product, but most o-rings are good for that I would think. Could be wrong -- any Chem-E's out there?

Another source is your local dive shop or restaurant supply house. You're looking for "food grade" silicone grease; divers use it on regulator O-rings, and restaurants use it to lube food slicers, etc.

We use it in the radio control model helicopter hobby to lube flapping dampers in rotor heads.

I would avoid ANY petroleum-based grease, to include Vaseline.

Anything wrong with general automotive grease? Like high-temp bearing grease?

I got a small tub from a dive shop more than a year ago I think, and I still have about 3/4 left... Dive shops first, else Radio shack carries a brand, I forget the name... not like they have Radio Shacks here anyway!! /ubbthreads/images/graemlins/grin.gif

I bought some at an auto parts store. VersaChem. "100% Pure Silicone Grease" called Silicone Brake Grease, about $4.00.

Be careful of hardware and auto store silicone grease. Many of them are not 100%. Read lables carefully. Dive shop is probably the safest, but most expensive, bet. Fortunately a very little goes a very long way!

Don't use any petroleum based lube on o-rings, it'll degrade the silicon.

Don't use a silicone based lube on silicone O-rings where an electrical connection is present (i.e. Surerfire tailcap O-rings). A chemical reaction occurs over time, causing a film to develop where the metal meets. This film will cause a voltage drop and possible other corrosion problems.

I lube my rings with a non-silicone based lube, sometimes called "switch grease." It's available at most R/C hobby stores.

--dan

Castle Brake Life.

Comes in a pressurized dispensing can. Use it to lube brake pads, sliders, swaybar bushings, and of course flashlight o-rings. One tube will probably last you many many years.

If you don't know of a local dealer, here's their site:

http://www.castleproductsonline.com/brake_lubricant.html

Mark

[ QUOTE ]
dano said:
Don't use any petroleum based lube on o-rings, it'll degrade the silicon.

Don't use a silicone based lube on silicone O-rings where an electrical connection is present (i.e. Surerfire tailcap O-rings). A chemical reaction occurs over time, causing a film to develop where the metal meets. This film will cause a voltage drop and possible other corrosion problems.

I lube my rings with a non-silicone based lube, sometimes called "switch grease." It's available at most R/C hobby stores.

--dan

[/ QUOTE ]

dano, can you elaborate more on this, is this chemical reaction something you can provide a link to that more fully explains it? Just curious, I have a local O-ring wholesale company in town that supplies industrial customers with orders that go into the millions, that I could speak to about those issues. This film, can any grease at all form a film from such a chemical reaction; and if so, how long does it take, or would it happen eventually even with the RC 'switch grease'?

Switch grease is specifically designed for what properties, surely not with any chemical reaction between o-rings?

'Where an electrical connection is present'...uh, are there not electrical connections present in all flashlights by virtue of having to power up a light engine? Seems that all flashlights, not just SF, have electrical connections present.

Since O-rings are available for many flashlights at a relatively low cost, I make it a preventative maintenance procedure to replace O-rings every other year, or more often. Reason being is that under compression, the O-rings flatten out and do not provide as good a seal as newer ones. I should think most divers change out 0-rings and other seals on their equipment regularly. But then again I know nothing, but I sure am more anal than most about maintaining a light at 'new' operating conditions.

Know anything about the additive Krytox from Dupont? I use a waterproof grease made by Finish Line Technologies, Inc (popular supplier of lubricants for bicyclists, among other things), that is stated for use with O-rings, in chemical environments, with instructions that "monthly re-application will ensure maximum performance & protection". I'll assume the RC 'switch grease' has the same advisement on routine maintenance/re-application?

I had been using petroleum jelly on o-rings for years, after all, Mag recommended it, and I even emailed them expressing my comcerns about it degrading the o-rings. They said it would be fine. I haven't has any problems, but have recently switched over to automotive dielectric tune-up grease. It doesn't feel quite as "lubed" or as smooth moving between the parts, but I'll give it a while to see the long-term results. After all, if it ruins an o-ring or 2, they're cheap and abundant at most good hardware stores, or from the flashlight manufacturers.

I tend to use only the 759G

On the few occasions I've needed some lubing, I grab the silicone grease that came with my trailer hook-up connectors. It's that little clear plastic "tube". Any reason I shouldn't be using this stuff? I keep forgetting to look for something else when I'm out-and-about.

Mark

I got mine from Lowes in the plumbing section for about $3.00
a small plastic tub of it on a card. Make sure and look on the label to see if it contains any petroleum by products or lists it as 100% silicone grease.