Lube for Silicone O-rings

This is NOT a question about silicone lube.

It's about lube for: o-rings made from silicone.

I'm considering switching some o-rings from nitrile to silicone (long story why), and I'm fully aware that using silicone grease on silicone o-rings makes them swell and nasty and otherwise not keep water out.

The only real reference I've found is for Molykote FS1292, which McMaster has, at $46 per tube. Yeeks. Although at 5 oz. it will last for awhile....

So the question is, does anyone have extensive real-world experience using Christolube (MCG 111, I believe) on silicone o-rings? Does it work? Do the o-rings behave? It seems like it should work, being a fluorinated material, and I have plenty.

Thanks!

All the best, James

For silicone o-rings why not use good old spit. Water serves as a lubricant & it's a heck of a lot cheaper than the fancy stuff. No need to worry about a compatible chemical compound.

It's probably best to use the manufacturer specified lube on silicone o-rings.

(another option: replace silicone o-rings with black rubber o-rings and use Christolube)

Just out of curiosity, what are the advantages of silicone over nitrile o-rings?

(do they justify the switch?)

Take Care,

ChrisS

Water (or spit) works fine for static seals like the door, but not so well for sliding seals like the buttons and knobs. You really want lube on dynamic seals to reduce friction. That being said I use Christolube on the silicone o-rings in my Inon strobes and haven't seen any sign of swelling or degradation. Since it is less sticky that most o-ring greases it seems to pick up less dirt and fewer fibers.

I just HAVE to ask...

If Christolube is for good photographers, do us bad photographers have to use Satanolube, likely picking up more dirt?

Silicone o-rings are designed for a wide range of temperature applications, but have some poor mechanical properties. They serve no advantage over nitrile for housings in the water temps that we experience. They do make for easier maintenance (as in they don't need to be greased). All the small control o-rings on housings are typically nitrile.

From Parker O-Ring Handbook

2.2.17 Silicone Rubber (Q, MQ, VMQ, PVMQ)

The term silicone covers a large group of materials in which

vinyl-methyl-silicone (VMQ) is often the central ingredient.

Silicone elastomers as a group have relatively low

tensile strength, poor tear and wear resistance. However,

they have many useful properties as well. Silicones have

good heat resistance up to 232°C (450°F), good cold

flexibility down to -59°C (-75°F) and good ozone and

weather resistance as well as good insulating and physiologically

neutral properties.

As a side note I've found S&S blue o-rings to be dust magnets & have changed all of mine to nitrile. Life is much easier if everything uses the same o-ring compound. Just need a tube of good quality silicone grease.

Life is much easier if everything uses the same o-ring compound. Just need a tube of good quality silicone grease.

Forgive my ignorance, but does this mean I can use just one silicon grease (e.g. The Ikelite one) for my Ike housing and also on my Nikonos strobes?

If so, why do the different manufacturers all seem to have their own silicon for sale? Is it just a ploy to make more money?

Jim,

From whom did you order the S&S replacement o-rings?

Mark

Forgive my ignorance, but does this mean I can use just one silicon grease (e.g. The Ikelite one) for my Ike housing and also on my Nikonos strobes?

If so, why do the different manufacturers all seem to have their own silicon for sale? Is it just a ploy to make more money?

This is diverging from the orginal post about Si o-rings. But, just to ensure that you understand... It may be a nuisance, but I always use the lube supplied by the manufacture on their product. DO NOT use Ike lube on Nikonos camera o-rings or Nikonos lube on Ike, Inon, S&S, ....?? products. In days of old, when I purchased an Ikelite product, it came with a tube of lube. Now in the days of cost cutting, one gets a skimpy amount of lube gratis. Fortunately, I still have beaucoup tubes from the past; one from 1975 Wonder why my wife says I never throw anything away?

My general point was that the various manufacturers have made all this o-ring stuff rdiculously confusing at times. Its not rocket science. If they would use one o-ring compound like standard nitrile it would save a lot of confusion for many of us. Do we really know whats in all these little tubes? Some are silicone, some are "special" & a few may just be silicone with a slight color additive just so we think its different. If the o-ring is black I use my Home Depot tube of silicone grease (lasts for ever). If its colored I change it to black.

Mark - I got my S&S nitrile o-rings (battery cap & sync cord) from the Service Center in Calif.

http://www.subaquaticcamera.com/

My general point was that the various manufacturers have made all this o-ring stuff rdiculously confusing at times. Its not rocket science. If they would use one o-ring compound like standard nitrile it would save a lot of confusion for many of us. Do we really know whats in all these little tubes? Some are silicone, some are "special" & a few may just be silicone with a slight color additive just so we think its different. If the o-ring is black I use my Home Depot tube of silicone grease (lasts for ever). If its colored I change it to black.

 

Mark - I got my S&S nitrile o-rings (battery cap & sync cord) from the Service Center in Calif.

http://www.subaquaticcamera.com/

In the lab we use a mixture of silicone and fluorosilicone oil for lubing silicone o-rings. In the ocean, I use fluoro lube from my bike shop for silicone o-rings. Christo lube also works with no swelling. A lot depends on the exact formulation of the silicone in the o-ring, some swell at the thought of lube, some don't ever swell even after soaking in the lube.

On the other topic, most silicone greases are pretty much the same, we have looked at a bunch in the lab and at least to first approximation there ain't much difference

Bill

Thanks for the replies folks. Especially thanks Steve for a reply directly to the question - using Christolube on silicone O-Rings.

Yes, yes, I usually refer to the manufacturer's supplied lube. However, in this case, all the manufacturer does is make o-rings.

The source is McMaster-Carr; I am considering replacing the active, barrel o-ring on my X-Scooter (which is currently a ShoreA duro70 Nitrile 2-261) with a silicone one in the same durometer.

The reason is that the X-Scooter is black, and it is tough to see the black o-ring on it; we dive often at Lake Tahoe, or at sea level, both of which are significant altitude change; if we assemble the scooter at home, it will be impossible to open at altitude or sea level; driving to site with the scooter dissassembled is a PITA, as it takes up too much space; if we assemble the scooter with the barrel o-ring missing, it will not trap pressure; assembled thus, it is easy to pack and very protected, and the sealing surface has a lightweight face seal to protect it from impact damage; it is easy to be forgetful and reassemble it without the barrel o-ring replaced; silicone o-rings are orange, and less likely to be overlooked. See, I told you it was a long story!

I also see that fluorosilicone o-rings (usually blue) are tolerant of plain ol' silicone lube, but cost $14 each, vs silicone at $2 each, or nitrile at $0.42 each.

Anyway, I'll give Christolube a try, and if it swells or otherwise is not good I'll let you know.

All the best, James

I am not surprised to find most all silicone grease is the same.

Then why does Inon go to such length in the instructions to require using THEIR grease only?

Anyone know?

Dave

I don't know, but the Molykote 1292 lube works on everything: I've used it with Nikonos, Anthis and Subal nitrile, Inon and Sea & Sea silicone and compact housings. It's a bit viscous when cold, but a little goes a long way.

I believe that the principle is that lube suitable for fluorosilicone is compatible with everything, and there is advice on the Cameras Underwater website in the UK.

Tim

Well, that figures.

I used to work in Midland for Dow Corning and had Molykote tubes I used at home and could buy it cheap.

You save and save stuff and still tossed the molykote some yrs ago. Not certain if it was 1292 however.

Now I have to pay retail for it.