Molykote 3451 vs. Tribolube 71

[DiverD 0]

I have a new Aquatica Housing for my Nikon D800, and I'm having a heck of a time removing the port covers (not due to any vacuum problem), and getting the extension ring off of the macro port. I spoke with Aquatica yesterday to see if there was any magic, and they suggested lubricating my O-rings. I'd already done this, of course, but the Aquatica supplied O-ring grease is of a different consistency than what I'm used to. It's kind of like a white paste. It's possible that the color is throwing me off, but it seems more tacky, and less slippery than the clear silicone grease I used to use with my Subal housing. Now I'm on a mission. I'm hoping to find an O-ring lubricant that can be used with both my Aquatica housing and my Inon strobes, that's slick and slippery. Has anyone compared the consistency of Dow Corning's Molykote 3451 to Tribolube 71? It sounds as though either of these can be safely used on any of my O-rings, but which ones would give me slicker, more slippery O-rings?

[diver dave1 23]

I have used Molykote 3451 for several yrs on Inon Z240 O-rings and Nexus housing O-rings. Works great and lubricates well. The Z-240 cap threads into place, as do Nexus ports/domes which benefits from the lubrication characteristics. Cannot compare it to Triolube as I have not used it. A few yrs ago, there were MANY thread regarding O-ring grease. You might do some searching here.

[ChrigelKarrer 52]

Well,
i suggest that you ask Aquatica what alternative grease you can use before a major desaster occures...

Thick and non slippery sounds like trio/christolube to me, but you better ask them again about what product it is.

 

Molykote 3451 = Fluorosilicone grease thickened with PTFE
Tribolube 71 = oxygen safe lubricant with PTFE (usually used on oxigen enriched scuba regulatros and valves)

Triolube 71 technical data states:
It is compatible with most elastomers and plastic seals,gaskets and O-rings.

Although this lubricant is very inert, newly exposed rubbing surfaces of aluminum and magnesium may react with the greases under certain conditions

Molikote 3451technical data sheet has a swelling diagram for various o-ring materials

Better ask than sorry!

Chris

Edited April 5, 2014 by ChrigelKarrer

[DiverD 0]

Thanks for the replies. I will check this out with Aquatica beforehand. Then, if both are safe, I may just buy them and see which feels more slippery.

[eyu 27]

I got tired of using separate greases for my different o-rings and have been using Triolube 71 as my o-ring grease for over 700 dives now.

I use Triolube 71 for Sea & Sea blue, Inon yellow, Olympus red and Subal black o-rings without any problems. It lubricates and prevents the Inon o-rings from binding when changing batteries and does not react with the different o-rings or my aluminum Subal housing.

 

Elmer

Edited April 7, 2014 by eyu

[DiverD 0]

Thanks for the information. Aquatica says Triolube 71 has their official blessing. They are not personally familiar with Molykote 3451, but feel that it's made by a reputable company, and should be safe for these purposes if Dow Corning says it is. I have ordered both, and will do the touch test when they are received.

[bvanant 195]

My understanding is that there is very little difference between the lubrication properties of Tribolube 71 and Molykote, but I will get some in our lab and see about sliding friction of the two. My guess is though that the differences will be tiny.

Bill

[DiverD 0]

That's awesome, Bill! Thank you!

[bvanant 195]

Well I wandered into the lab and made some measurements (usually they only let me in to get water for my coffee machine) and I was quite surprised by what I found. I used two aluminum (aluminium to those of you in the real world) blocks to measure the sliding coefficient of friction and a force gauge to measure the stiction between the two plates when the bottom plate is clamped down and I pull on the top plate.

 

To start I used Al/Al and measured f for this system at between 0.47 and 0.48 for 20 runs. Then I used a commercial MoS based grease and the f went down to about 0.06 or 0.07 (20 measurements with no control of the thickness of the grease). Then I used commercial silicone grease (triton tub) and found that the f value was about 0.33 to 0.34. This suggests that in this test at least, sliding friction was only reduced by about 30% (I was expecting a lot more). With the tribolube 77 and 66 the f values were about 0.09 to 0.10 and with the Molykote the f value was statistically the same. No differences in running friction at all.

 

For stiction, I pushed on a force gauge attached to the top block and calculated the force that it took to start the block moving. Again surprisingly the Trident actually increased the stiction a bit. Naked, clean Al vs. Al, required about 370 g to start sliding, the Trident grease took 450 to 460 g to start sliding. The Tribolube and Molykote samples took between 240 and 250 g.

 

Conclusion is that there is minimal difference between the two polyfluoro lubes, and both (from a slipperiness standpoint are better than Trident (thick grease).

 

Bill

[DiverD 0]

You're The Man, Bill! I think this qualifies you as the world's leading authority on lube! Thank you!