I tried silicone grease in a tube from AliExpress. I used it on a swimming pool chlorinator, which has a giant O-ring. It seemed to gum up and did not offer a lot of lubricity.
It was ok for flashlights, but I much prefer and now only use Danco 88693P. It is readily available in local hardware stores, Home Depot and Amazon sometimes has a great deal on it.
Thanks for the reply, my grease also seems to get dark as soon as I applied it. I used alcohol wipes to clean the threads beforehand, but still the grease turned grey after application.
I live outside the US, but will check my local hardware stores for Danco
Ah yes, plumbing grease. Saves you having to faucet.
Do you recommend Danco plumbing grease for flashlights?
Also outside of the USA don’t know of it. I use Superlube (I think the “synthetic grease” variety) its pretty cheap for a tube. Bought mine from Amazon or ebay in the UK.
The grease doesn’t know I’m putting it on a flashlight. It sees there are treads and thinks it is a piece of pipe.
vaseline - I’ve been using it on mtb suspension seals, o rings etc for years. I don’t bother with silicone grease anymore. I think it’s based on pure mineral oil (think unscented baby oil).
I had the same problem in Australia and ended up find Krytox grease (someone recommended it in another thread) on Ebay. It wasn’t cheap (about AUD$20 delivered) but that came via DHL from Germany! It’s only a very small tub but should last a long time. Here’s the link Krytox GPL 205 Grade 2 From Chemours 4270002821514 | eBay
All the Superlube varieties got very confusing as the part numbers/ names seemed to be different locally and it was also expensive (but admittedly you got more quantity.)
Industrial-grade greases like Krytox and Molykote (Dow-Corning) 111 aren’t cheap, and probably overkill for these applications.
I have some of the Xtar-branded grease, but also the Danco plumbing grease, which like Super Lube, is cheap and readily available in the U.S.
For those in the US: Mountain Electronics stocked silicon grease for flashlights. Ordered it along with some drivers and am quite pleased with it.
Hope they get it back.
[quote=poohduck]
vaseline - I’ve been using it on mtb suspension seals, o rings etc for years. I don’t bother with silicone grease anymore. I think it’s based on pure mineral oil (think unscented baby oil).[/quote
I was under the impression that Vaseline would make O rings swell because its petroleum based.
Nothing can beat the value of my 3 oz Motorcraft XG-12 (rebranded Nyogel 760G) which I bought from RockAuto for only $9 USD!
no, it’s safe. All suspension greases (or most of them) are petroleum based. Mineral oil (baby oil) is just mineral oil with no additives. It’s the additives in automotive oil and greases that are the problem. Suspension oils are also mostly petroleum based - some high end stuff is synthetic.
Vaseline will be no problem! Nitrile o-rings (the typical back rubber type) are designed to be used with hydraulic oil, amongst other things, which is petroleum based. In the hydraulics industry we often use white petroleum jelly to hold o-rings in awkward spots until the mating part can be assembled.
This is essentially SuperLube.
MTN states:
- Food Grade Grease
- High Dielectric Strength
- Excellent Heat Transfer Efficiency
- Thermally Stable
- Compatible with All Major Rubber and Plastic Compounds
- Fortified with PTFE
Which is the same as what SuperLube advertises: Super Lube Silicone Lubricating Grease with Syncolon (PTFE)
No, they are different. I’ve used the MTN silicone grease a lot and like it, and I’ve used the general SuperLube for over 20 years now. Not the same things at all. In the most recent grease thread I added a post at the end where I purchased some of the SuperLube silicone grease (marketed as o-ring grease) and it’s really nice, darn near the same thing as the MTN grease. Who knows what Richard was packaging, good stuff, though.
OP, I think the Xtar grease you have is probably just fine. Apply it sparingly to threads…too much will just make a mess but also shouldn’t really interfere with conductivity (most gets squished away from the pressure and shear force as the threads are tightened and mate together so there will always be enough metal-to-metal contact even in designs where tube shoulders are butting together before the threads can really be mashed tight). The grey color you’re seeing right away is just residue/oxidation/metal dust that was left over after you cleaned…if you wipe away the new grease really well and reapply, that grey should be less and it probably won’t get as “dirty” over time, just depends on the host aluminum and quality of machining really.
I find it hard to believe that the grease MTN sells is not SuperLube since they use almost identical descriptions. Maybe MTN sells the o-ring version, but that’s not compatible with silicone o-rings. Or perhaps MTN sells another version.
But I guess I/we can’t be sure one way or the other. Glad you like the MTN grease you got though! 
Richard would have to tell us what he buys. SuperLube as a company does not actually manufacture every item they sell, either, so it’s always possible that someone found a buyable-source further upstream. Anyway, they’re all fine (save for potential compatibilities as you mentioned). I hope he’s doing fine and the business is sustaining…kinda wondered from time to time.
It appears Mountain Electronics is still doing fine, but who knows for sure. I placed an order with them last month. Seems strange that they still don’t sell the incredible 519As yet! I sure would miss them if they went away.
Thanks for the reply. The metal to metal contact makes sense. The host I applied it to was indeed a cheaper flashlight with low quality anodizing. Ill wipe the grease off and try with a new layer.