Interchangeable brands of silicone grease for o-rings?

To Tom's point, Parker makes some nice lubes , but they are not universal lubes, just silicone oil which can seriously swell silicone o-rings (they are good for nitrile).  Tribolube, Christolube, and any of the other per-fluoro ether materials are good for any kind of o-ring.

Bill

10 minutes ago, bvanant said:

To Tom's point, Parker makes some nice lubes , but they are not universal lubes, just silicone oil which can seriously swell silicone o-rings (they are good for nitrile).  Tribolube, Christolube, and any of the other per-fluoro ether materials are good for any kind of o-ring.

Bill

Correct. They also make this: https://ph.parker.com/us/en/general-purpose-barium-grease-lubricant-hydrocarbon-service-and-pneumatic-systems-under-200-psi-translucent-o-lube/olube-884-2

Barium lubes are used in cars. It may be cheaper too. It is NOT recommended for silicone. The older lube that I am using is supposed to be universal - it has a yellowish color.

I am pretty sure that the current Parker silicone grease (sorry a high viscosity silicone oil; I suspect that Parker calls an oil with filler a grease) will swell silicone o-rings. I wouldn't put barium grease near my housing. For universal o-ring lubes I think any of the  Christolube/Tribolube/Krytox greases will work.

Bill

20 minutes ago, bvanant said:

I am pretty sure that the current Parker silicone grease (sorry a high viscosity silicone oil; I suspect that Parker calls an oil with filler a grease) will swell silicone o-rings. I wouldn't put barium grease near my housing. For universal o-ring lubes I think any of the  Christolube/Tribolube/Krytox greases will work.

Bill

 

Correct, Parker does not recommend it either hence my capitalization. I am only familiar with using barium grease to lubricate car axle parts and have done so myself. Unfortunately the stuff I am using for my housings is apparently no longer for sale.

So when the silicone o-rings swell does it degrade the material? I ask because I would like the o-rings on my strobe arms to be a little thicker but haven't found any with the needed ID that have a slightly greater OD.

10 hours ago, rwe said:

So when the silicone o-rings swell does it degrade the material? I ask because I would like the o-rings on my strobe arms to be a little thicker but haven't found any with the needed ID that have a slightly greater OD.

Yes it degrades the material, what problem are you trying to solve with thicker o-rings?

The o-rings on most strobe arms are size 2-209. You might be able to get some metric ones that are a bit larger or smaller but I am too lazy to figure that out. What is more useful I suspect is to change the material of the o-rings. Durometer and chemistry will make  a big difference in terms of being able to tighten appropriately. 

Bill

On 11/20/2021 at 6:56 PM, rwe said:

So when the silicone o-rings swell does it degrade the material? I ask because I would like the o-rings on my strobe arms to be a little thicker but haven't found any with the needed ID that have a slightly greater OD.

There is no guarantee that they will swell or loose shape equivalently all through. One can't control this. And yes degradation is a definite possibility in time.

1 hour ago, diggy said:

There is no guarantee that they will swell or loose shape equivalently all through. One can't control this. And yes degradation is a definite possibility in time.

It will probably also soften and lessen the ability for the clamp to hold.

On 11/20/2021 at 5:26 AM, rwe said:

So when the silicone o-rings swell does it degrade the material? I ask because I would like the o-rings on my strobe arms to be a little thicker but haven't found any with the needed ID that have a slightly greater OD.

I think "swelling" is used in a more general term for o-rings degradation. Mine actually did not get thinker (from what I can tell) but got longer, and I only noticed when I could no longer close up the camera as the o-ring would bulge.

A lot depends on the material and the stuff you put on it. During manufacturing of some implantable medical gizmos we would routinely swell a silicone o-ring to get it large enough to slide over an actuator. We should use something volatile so that when it evaporated the o-ring was back to normal size. The math of the swelling is complex i.e., does the hole in the center get bigger or does the wall thickness get larger.  In any case swelling with silicone oil should be pretty irreversible, mostly that stuff stays on a surface forever.

Bill