To lube or not to lube O-rings?

[Akimbo]

I guess I'm more interested in "should I lube" versus the lube itself. If DGX says no, shouldn't I abide? Maybe I'm overthinking again.

For high pressure breathing gas applications NASA, the US Navy, and O-ring manufacturers disagree. The caveat is properly lubricated, meaning the right lubricant and a very light coating.

No lubrication can suck less than the wrong lube or too much, but it still sucks.

 

[herman]

IMO, The SPG spool is the one exception to the lightly lubed rule. Those spools are bad to corrode in place due to water getting in and it really can't be rinsed out. Once corroded in, you usually damage the hose and/or SPG trying to get it out. I put a good bit of lube in the area between the end of the SPG and the hose, this seals the area and keeps water from getting between the hose, spool and SPG.

 

[johndiver999]

IMO, The SPG spool is the one exception to the lightly lubed rule. Those spools are bad to corrode in place due to water getting in and it really can't be rinsed out. Once corroded in, you usually damage the hose and/or SPG trying to get it out. I put a good bit of lube in the area between the end of the SPG and the hose, this seals the area and keeps water from getting between the hose, spool and SPG.

I always gunk a bunch of lube on both sides of the spindle and a bunch on the threads of the connection as well.

When it gets tight and hard to spin, then I open it up and reapply lube. If it starts leaking (more than a little) it gets new orings or a new spindle. If you aren't generous with the lube on the threads it is harder to remove the spg and maintain it. For a lot of o-rings it is important that no water get past them.

For these orings, a tiny bit of high pressure air leaking out is not a big deal, so the grease potentially attracting grit doesn't seem that important. The orings only need to be pretty good in this application - not like an expensive camera is going to flood.

Plus, I would assume that if too much grease is applied, it is just going to be extruded over time by the 3000 psi pressure. Again, not a big deal.

 

[ScubaTexas]

Good discussion in this thread, which got me asking what's the thought on what to use to apply the lube to the o-ring? Finger tip or something like a silicone tip? I have always used a clean finger tip to put just a shine of lube on o-rings but recognize the approach introduces the possibility of errant grit, lint, or hair getting on surface. The possible contamination comes into play particularly for camera housings (had one flood 10 years ago from a small piece of hair - careless on my part). Wondering if there is a better application approach to consider using?

 

[Akimbo]

Finger tip or something like a silicone tip?

Depends on the size and application. Q-tips are a bad idea because the they leave loose fibers behind. I have been using disposable foam make-up swabs for cleaning O-ring grooves and apply thin films of lube. That said, fingers are often the only tool that works.