Enhancing An O-Ring Seal?

Silicone *lube* is what is typically used on O rings for PVC unions and such.

Silicone grease. You can get it at your local SCUBA shop since it's used on O-rings in UW camera gear, lights, etc.

I've been using Vaseline on all my in-ground pool piping's O-rings for years. It has never attacked the o-rings and I've never had to replace any of them. The pool was installed in 1986.

PS. I take apart the pool filter every Autumn and store it inside for the Winter, then reinstall it in the late Spring.

Some kind of grease is the answer, the issue is that vaseline might be perfectly safe for some kinds of rubber and not others, the same may be true of silicone grease (likely one or the other will work though.)

nate

Pete:

Your best bet would be to get a set of dental picks so that you can take the old O-ring out, and then just put a new O-ring, or one size larger O-ring in for a better seal.

Here, I wrote up a blurb about O-rings while I was posting on a board before I came here. Lemme find that write-up.

The classic and well proven thing to use for such applications is silicone grease. It is inorganic (obviously) and won't attack rubber.

That is what I use for all of my sealing needs of this sort. Dow 111 It will also hold PVC pipe joints together under low pressure operation without leaking. (40" of water or so)

PC-

Most of the comments thus far have helpful.

I would suggest avoiding the use of vaseline & stick with the silicone lubes, valve stem lube, etc (compatible with rubber O-rings).

Depending on the exact design of the camera & O-ring sealing means.... moisture could be getting in through a different route. Another thing to consider...sometimes over tightening can reduce sealing effectiveness.

cheers Bob

Per nestork:

In the interest of brevity, I lied a little about the o-ring. It's a custom shape to accommodate a few screw holes.

I think I'm going to go the silicone grease route. If that fails, I'll just remove the o-ring, set the joint in marine silicone sealer, and hope I don't need to disassemble it too often.

Can you use a plumbing sealer like teflon tape there? Plumber's putty? Plumber's putty that isn't too too old is easy to remove with a Q-tip dipped in mineral spirits.

silicone grease - won't attack the rubber, won't glue it together, and seals against moisture intrusion. Can't remermber the brand I use

- but it is a food-grade grease used in food production lines.

I looked at the diagram for the pool pump you posted. In my experience, that large and small O-ring together shouldn't cost any more than $2 or $3 in nitrile at any shop that sells O-rings. The manufacturer will charge you $25 for those two O-rings as a repair "kit", but only people that are scared to buy anything but OEM repair parts would ever pay that much. Maybe just take your old O-rings down to any place that specializes in pneumatic and hydraulic seals, and they'll size the O-rings for you. EVERY O-ring meant for plumbing applications I've ever come across has been 70 durometer hardness, and so if you buy 70 durometer nitrile rubber O-rings to replace what you have, they should work fine for you.

The "o-ring" on an underwater camera case is not a round o-ring you can readilly get a replacement for - it is generally a pretty long o-ring formed to fit the perimeter of the case.. And no dental pick required to remove it.

The silicone grease WILL do the job unless the o-ring is badly deteriorated.

I wouldn't go close to my camera case with plumbers putty!!. You can do what you like with yours. Silicone Grease has been the standard solution for this problem with divers and photographers for almost 30 years (possibly even longer) - because it works and does not cause other problems. It is very easy to purchase, use, and remove.

Per snipped-for-privacy@snyder.on.ca:

I'm going to Home Depot today.

Hit the local hardware store, and could not find anything explicitly "Grease". A lot of "Silicone Compound" stuff - and I even have a tube of that already..... but I'm guessing there is some significant diff with "Compound" vs "Grease". In fact, the stuff I have looks more like lubricating gel that grease.

Use a silicon grease made for sealing against liquids. Fountain pen owners use it to seal ink reservoirs. You can buy it in small amounts that won't break the bank:

Inspect the oring with a minimum 5X magnifier for excess or negative casting flash. Make sure the oring is does not have cuts or defects. Inspect the oring grooves for scratches or dings. You can smooth 'em out with some 400 grit wet/dry sandpaper. If all is well, grease 'er up and reassemble.

nb

For most o-ring situations, the preferred lube is "high-vacuum silicone grease". But it is expensive. Plumber's silicone grease is a good substitute.

But before you goop things up, keep in mind that the elegant o-ring is dependent on clean, smooth, scratch-free surfaces. And the o-ring has to be pristine. Never use metal tools to dig an o-ring out its home. A strong hand lens and strong lighting are essential for inspecting o-rings and o-ring-groove sealing surfaces. The slightest scratch across the surface, or the slightest nick in the o-ring itself can be un-fixable with lube. An eyelash can cause a serious leak!