Replacing Hose / o-rings: when to use lubricant?

[BobbyWombat]

OK,

So I've been reading some threads since I need to change out my LP inflator hose for my new BC. Looks pretty easy, but one question I have is what o-rings should get some lubricant, and which ones don't need it?

It seems from what I have read that static o-rings don't need lubricant. You screw it on and leave it. O-rings that seal against something moving or are loaded/unloaded often like on a camera housing ("dynamic o-rings") need to be lubricated.

If using air and only air, silicon lube is OK. If using or could use Nitrox, you need to use christolube.

Does that sound right????

[in_cavediver]

Originally Posted by BobbyWombat

OK,

So I've been reading some threads since I need to change out my LP inflator hose for my new BC. Looks pretty easy, but one question I have is what o-rings should get some lubricant, and which ones don't need it?

It seems from what I have read that static o-rings don't need lubricant. You screw it on and leave it. O-rings that seal against something moving or are loaded/unloaded often like on a camera housing ("dynamic o-rings") need to be lubricated.

If using air and only air, silicon lube is OK. If using or could use Nitrox, you need to use christolube.

Does that sound right????

Yep. That pretty much covers it. Two minor differences. Even if its static, sometimes I'll add a bit of lube. Thinking tank o-rings here. Just makes it easier to get together and apart. Small stuff like Reg hoses i keep dry.

Also, I am lazy. I only use 02 compatible lubricant on everything. For a single diver, its not cost prohibitive. I'm on the same 'tub' for the last 6 years and I rebuild regs, BC inflater's and VIP tanks.

[PsychDiver]

When putting on silicone grease use a very small amount and rub it between the tips of your thumb and index finger. Then coat the o-ring without causing any build up by rubbing the o-ring between your thumb and index finger. Make sure you use a O2 o-ring and silicone approved for O2 if your are using the o-ring on a device that will be used with nitrox or other mixure.

[robjoubert]

This thread has made me realize that I need an inflator hose - especially as I have just bought a new first & second stage, octo abd dive computer form ST!!

Are the inflator hoses standard for all BC's - or is the hose I need dependant on the BC I have and use?

[texdiveguy]

I never lube the static o-ring at the cylinder valve to cylinder connection as it greatly increases the chance of a ring 'bulge' out...I have seen it happen with other divers.....leave this ring dry IMO.

[No Misses]

Inflator hoses do come in different legths. The most common is 22". I think that mine is 15". I'm not positive, but I can check when I get home.

[in_cavediver]

Originally Posted by texdiveguy

I never lube the static o-ring at the cylinder valve to cylinder connection as it greatly increases the chance of a ring 'bulge' out...I have seen it happen with other divers.....leave this ring dry IMO.

Actually, your right. Thinking about it, I lube the threads, not the o-ring on the tank..

[BobbyWombat]

Originally Posted by robjoubert

This thread has made me realize that I need an inflator hose - especially as I have just bought a new first & second stage, octo abd dive computer form ST!!

Are the inflator hoses standard for all BC's - or is the hose I need dependant on the BC I have and use?

When you buy a BC, it should come with an appropriate length hose. I *think* the quick disconnect is pretty standard among different brands, but you may want a different length hose depending on your BC setup.

I had a "generic" BC inflator hose that was long enough for a typical jacket style BC. When I bought my BP/W, it came with a shorter hose, more appropriate for that style of BCD. (a longer hose would loop out instead of staying streamlined over your shoulder).

--------
All - thanks for the great input.

[BobbyWombat]

OK,

Next question: hose protectors.

Any tips/tricks for getting them on and off yourself??

[WaScubaDude]

Originally Posted by robjoubert

This thread has made me realize that I need an inflator hose - especially as I have just bought a new first & second stage, octo abd dive computer form ST!!

Are the inflator hoses standard for all BC's - or is the hose I need dependant on the BC I have and use?

Some are propritary. I think there are about 3 different types of fittings, not including those for an integrated octo/inflater. There is one that is fairly standard and common. Just let ST or your lds know what brand of BC/inflator you are using and they can hook you up.