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Quick answer from a licensed plumber: They seal different things. Teflon (PTFE) tape and pipe dope seal threaded pipe joints (tape for most home jobs, dope for larger/metal or gas-rated work). Plumber’s putty seals under fixtures like sink drains and faucet bases. Silicone is a permanent waterproof caulk for seams and gaps. Using the wrong one is the #1 cause of leaks I get called to fix.
Which Sealant for Which Job
| Product | Use it for | Don’t use on |
|---|---|---|
| Teflon tape | Threaded pipe connections | Compression fittings, drain bodies |
| Pipe dope | Metal/large threaded joints, gas (rated type) | Plastic threads it can attack |
| Plumber’s putty | Under sink drains, faucet/strainer bases | Plastic that cracks, pressure joints |
| Silicone | Permanent waterproof seams, gaps | Threaded pressure joints |
Teflon Tape vs Pipe Dope
For threaded joints, Teflon tape (3–5 wraps, clockwise) handles nearly every household connection. Pipe dope is preferred on larger metal threads and is required in a gas-rated version for gas lines. Many pros use both on critical joints.
Ready to buy the paste side? The two cans worth owning are in the pipe dope guide.
Plumber’s Putty vs Silicone
Plumber’s putty stays pliable and is perfect under a sink drain or faucet base because it’s removable for future service. Silicone sealant cures hard and permanent — great for a backsplash or shower seam, wrong for anything you’ll need to take apart.
The Plumber’s Verdict
Keep all four on the shelf — they’re cheap and each solves a different leak. Tape/dope for threads, putty for fixture bases, silicone for permanent waterproofing.
Where to Buy
Check current prices on Amazon: Oatey 31199 white PTFE thread seal tape · Pipe joint compound (Oatey Great Blue) · Oatey 31177 plumber’s putty · GE Advanced Silicone kitchen & bath sealant.
Full write-ups on each: the tape guide, pipe dope guide, putty guide and silicone guide.
Related: sealant only belongs on tapered male threads — decoding which is which: MIP, FIP and NPT explained.
#ad Buying for a shop? Amazon Business (opens in a new tab) accounts are free to create, with business-only prices and bulk quantity discounts.
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FAQ
Can I use Teflon tape instead of plumber’s putty?
No — they do different jobs. Tape seals threaded joints; putty seals under fixtures like sink drains. They’re not interchangeable.
Which way do I wrap Teflon tape?
Clockwise (the direction the fitting threads on), 3–5 wraps, so it tightens rather than unravels.
Is plumber’s putty or silicone better for a sink drain?
Plumber’s putty for most metal sink drains (removable later). Use silicone for some plastic fixtures or where the manufacturer specifies it.
The Rule That Prevents Most Leaks: Threads or Surfaces?
Almost every sealant mistake comes from mixing up two completely different jobs. Tape and pipe dope seal tapered pipe threads — metal or plastic threads that wedge tighter as you turn them. Putty and silicone seal a flange against a flat surface, like a sink drain body sitting on the bottom of a basin. Get that pair straight and the rest is detail.
Where You Should Use None of Them
This is the part that costs people a second trip to the store. Several connections are designed to seal without any sealant at all, and adding some can actively stop them sealing:
- Compression fittings (the angle stops under your sink). The brass ferrule deforms against the tube — that is the seal. Dope on the threads is at best a lubricant and never the fix for a weeping compression joint; a fresh ferrule is.
- Slip-joint nuts on a P-trap. The nylon washer seals. Tape or putty in there can hold the washer off its seat and cause the leak you were trying to prevent.
- Flare fittings. Metal-to-metal on the flare face. Nothing goes on the face.
- Hose-thread connections — washing machine hoses, garden hoses, supply lines with a built-in gasket. Straight threads plus a rubber washer. If it drips, replace the washer.
Match the Tape to the Job
PTFE tape is color-coded, and the colors are not decoration:
| Color | What it’s for |
|---|---|
| White | General water lines. The everyday roll — Oatey lists its 31199 white at 3 mils. |
| Yellow | Fuel gas. Rated for gas piping — use this, not white, on a gas connection. |
| Pink | Water lines. Not a thicker tape — Oatey lists its 31402D pink at the same 3 mils as its white. |
| Green | Oxygen service — grease-free. Not something a homeowner will need. |
| Grey | Stainless steel, to resist galling on the threads. |
Wrap it clockwise as you look at the open end of the male thread, three to five turns, snug into the threads. Wrapped the other way it unwinds as the fitting screws on. On tapered threads you can use dope over tape — that is normal practice, not belt-and-braces.
Two rolls cover a house: Oatey 31199 white PTFE tape for water threads, and Harvey yellow gas-line PTFE tape — the maker recommends that one for lines carrying natural gas, propane and butane — for anything on the gas side.
Two Things Worth Knowing About Putty
- Standard putty can stain stone. On granite, marble or any porous countertop, use a putty labelled non-staining — Oatey 31177 plumber’s putty is sold as a non-staining formula the maker lists as safe on granite, marble, quartz and other porous surfaces. The regular oil-based stuff can leave a dark halo you cannot get back out.
- Putty is not glue and not for pressure. It seals a flange under compression and stays serviceable, which is exactly why plumbers like it on drain bodies. It has no business on a pressurised joint. Silicone bonds and waterproofs instead — better grip, harder to take apart in five years when you need to. The tube for that job: GE Advanced Silicone kitchen & bath sealant.
For the plumbers reading this
Most of this site is written for homeowners — this page clearly isn’t. If you’re in the trade and want the occasional straight-shooting note when I publish something like this (fittings comparisons, tool tests, code changes), drop your email. No spam, no course funnel, written by a licensed GA journeyman.
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