The Old Tradesman

Bench note No. 3

Grease the O-Rings

Which grease goes on faucet O-rings, how much of it, and what never to use.

  1. The Old Tradesman squints at a small black rubber O-ring held between his thumb and forefinger

    Panel 1. The Old Tradesman says: Look at it before it goes in. Cracked or worn? It gets replaced, not greased.

  2. The Old Tradesman pushes a wide jar away across his workbench with a flat hand

    Panel 2. The Old Tradesman says: Not this. Anything with petroleum in it goes after the rubber.

  3. The Old Tradesman squeezes a small dab of silicone grease from a tube onto his fingertip

    Panel 3. The Old Tradesman says: Silicone grease. A small dab. If you can see a gob of it, that is too much.

  4. The Old Tradesman rubs silicone grease around a black O-ring on a slim faucet cartridge with a brass stem

    Panel 4. The Old Tradesman says: A thin film on every O-ring. Round and round until it shines.

  5. The Old Tradesman lifts the lever handle of a kitchen faucet with one finger and gives a thumbs up

    Panel 5. The Old Tradesman says: One finger. That is how a handle should move.

The note

Rubber against brass with nothing between them is a fight, and the rubber loses. So before an O-ring goes in, it gets grease. The right grease. And before the faucet comes apart, the water goes off and the handle gets opened.

The right grease is silicone-based. Moen says to lubricate its 1225 cartridge inside and out with a silicone-based grease. It rules out plumber’s grade faucet grease, silicone sprays and any lubricant that may contain petroleum, because petroleum-based lubricants may react with the rubber seals. Kohler is blunter: petroleum-based lubricants will harm the O-rings, seals and plastic components. So the jar from the medicine cabinet stays in the medicine cabinet.

This water is headed for a glass, so use a grease made for that. Danco says its silicone faucet grease is NSF 61 approved, and Oatey calls silicone grease the go-to for parts that touch potable water.

How much? This Old House says a small dab around the O-rings, and gives the reason: less friction, so the O-rings last longer. Some makers want more than the rings done. Danco’s sheet for one of its cartridges says to grease about an inch inside the valve body as well. Some kits come with the grease in the box, and Kohler’s seal kit is one. Makers differ, so the sheet for your faucet wins. Read it.

Grease is not a repair. A cracked O-ring gets cut off and replaced. A worn one gets replaced, or the whole cartridge does. Grease a bad ring and all you have is a slippery leak.

References

  1. Moen, Handle is difficult to operate
  2. Kohler, Installation and Care Guide 1110626-2
  3. Danco, 0.5 oz. Silicone Faucet Grease
  4. Oatey, The Ultimate Guide to Choosing and Using Plumbing Grease
  5. This Old House, How To Fix a Leaky Faucet
  6. Danco, Replacement Cartridge for Delta Monitor Single Lever Faucets
  7. Kohler, Replace Seals on a Single-Control Kitchen Faucet
  8. This Old House, How to Repair a Dripping Single-Handled Faucet
  9. Family Handyman, How to Fix a Leaky Faucet

The technique in this note comes from these sources. He is the voice. They are the authority. The panels are cartoons, not photographs.