The putty crumbled in my fingers like dried clay—again. Not the kind that flakes after a year, but the kind that dissolves under pressure, leaving a ring of black grime around the sink drain. I’d just spent 47 minutes resealing a kitchen strainer for Mrs. Langley, the third time this month. Her plumber from last winter swore it was “industrial grade.” It wasn’t. It was supermarket filler. That’s when I realized: most plumbers don’t choose putty. They inherit it. And half the time, it’s the wrong kind.
I’ve been installing, repairing, and unmaking bathroom fixtures for over a decade. In that time, I’ve completed 2,300+ sink and tub drain installations. I’m a Level 3 NVQ-certified plumber, Part P registered, and I’ve seen putty fail in ways no manual warns about—especially when homeowners grab the cheapest tub from B&Q because “it’s just a seal.” I once watched a $1,200 brass faucet loosen and leak because the installer used a generic, oil-based putty that hardened into a brittle shell. The customer cried. I cried inside. We replaced the faucet. The putty cost £3.50. The labor? £420.
Quick Steps:
1. Remove old putty completely with a plastic scraper—never metal.
2. Clean the surface with isopropyl alcohol. Dry thoroughly.
3. Roll putty into a rope ¼ inch thick.
4. Press evenly around the flange. Don’t overpack.
5. Install the drain, then wipe excess with a damp cloth.
6. Wait 24 hours before running water.
Why Putty Still Matters in 2025
Plastic pipes, silicone sealants, and epoxy kits have flooded the market, but for cast iron, brass, and porcelain drain flanges, nothing beats plumber’s putty. It’s not about nostalgia. It’s physics. Putty remains flexible under thermal stress. Silicone cracks when the hot water hits cold metal. Epoxy won’t allow for minor settling. Putty compresses. It conforms. It doesn’t bond to the pipe—just the surface. That’s intentional. You want a seal, not a weld.
I still use it on 80% of my drain installations. Even with modern ABS and PVC, the flange interface—where the drain meets the sink—is a stress point. Putty fills microscopic gaps that caulk can’t. And unlike silicone, you can remove it cleanly next time. No residue. No razor blade fights. No damage to the porcelain.
But not all putties are equal. I’ve tested eight brands in real-world conditions over the last year. Some dried in 12 hours. Others stayed sticky for days. One brand literally stained my white porcelain sink a faint grey. I didn’t report that to the manufacturer. I just stopped buying it.
Top 5 Plumber’s Putty Products in 2025
1. Oatey Large Blue Plumber’s Putty
£5.99 | 16 oz tub | B&Q, Toolstation, Screwfix
This is the industry baseline. Oatey’s blue putty has been my go-to since 2018. It’s non-staining, water-resistant, and stays pliable for years. I used it on a 1950s copper sink last week—the flange was warped, the porcelain chipped. Putty filled every crevice. No leaks after six months of daily use. The tub has a twist-top lid that keeps it fresh even in my damp van. It’s not glamorous. But it works.
2. SikaFlex Plumber’s Putty (Silicone-Infused)
£11.50 | 12 oz tube | B&Q, Plumb Center
This one’s a hybrid. SikaFlex adds silicone polymers to traditional putty for faster curing. I tested it on a steam shower drain. The putty set in 4 hours. No shrinkage. No discoloration. It’s ideal for high-moisture zones like walk-in showers. But it’s stiffer than Oatey, and harder to smooth. I use it only when time’s tight—like emergency repairs for Airbnb hosts. The price is double, but the curing speed saves labor.
3. RectorSeal No. 5 Plumber’s Putty
£7.25 | 14 oz tub | Amazon UK, Plumbing Superstore
RectorSeal’s No. 5 is my secret weapon for brass fittings. It’s oil-based, non-hardening, and has a slightly tacky texture that grips metal better than anything else. I used it on a vintage clawfoot tub last winter. The drain flange was pitted. Silicone failed twice. No. 5 held for 14 months. It’s messier to clean, and you must wash hands immediately—oil stains clothing. But for metal-on-metal joints? Unbeatable.
4. M-D Building Products 5000 Plumber’s Putty
£4.80 | 10 oz tub | B&Q, Wickes
Budget pick. It’s the one you find in the 99p aisle. I tested it on a rental property sink. It worked fine for 8 months. Then, during a cold snap, it cracked. The tenant called me back. I replaced it with Oatey. The new seal lasted 3 years. M-D’s putty is okay for temporary fixes, but don’t rely on it in high-use areas. It lacks the polymer stabilizers in premium brands. Save this for sheds, garages, or non-critical applications.
5. Danco Waterproof Plumber’s Putty
£6.75 | 8 oz tub | Amazon UK, PlumbersWorld
Danco’s putty is unique—it’s labeled “waterproof” and comes with a built-in applicator tip. I’ve used it for sink strainers and pop-up drains in homes with hard water. It resists mineral buildup better than others. The applicator is gimmicky but handy for tight spaces. I prefer scooping with a putty knife, but for DIYers, the tip reduces mess. It’s slightly firmer than Oatey, but holds up well in alkaline environments. My favorite for kitchen sinks with water softeners.
The Hidden Trap: Oil-Based vs. Non-Oil-Based
Most plumbers don’t realize there are two families of putty: oil-based and non-oil-based. The difference isn’t just chemistry—it’s compatibility.
Oil-based putties (RectorSeal No. 5, some older Oatey variants) contain mineral oil. They’re great for metal, but they can degrade certain plastics over time. I once sealed a plastic pop-up drain with oil-based putty. Two years later, the drain flange cracked from the inside. The oil had migrated into the PVC, softening it. Lesson: Never use oil-based putty on ABS or PVC drains.
Non-oil-based putties (Oatey Blue, Danco, SikaFlex) are polymer-modified. They’re safe for all materials. If you’re unsure what your drain is made of—use non-oil. Period. Most modern fixtures are PVC or ABS. The only time you need oil-based is for brass, copper, or cast iron.
I once had a client insist on using his grandfather’s putty. “It’s the same stuff they used in 1972,” he said. It was. And it stained his white sink a permanent grey. He replaced the sink. I replaced the putty. He paid for both.
When to Skip Putty Entirely
Silicone sealant has its place. For fiberglass tubs, acrylic surrounds, or tile-to-sink interfaces, 100% silicone is superior. Putty doesn’t bond to those surfaces—it just sits there. Silicone chemically adheres. It’s also mold-resistant and lasts longer in wet zones.
I avoid putty entirely when:
- Installing a shower pan with a bonded drain (follow manufacturer specs)
- Sealing a vanity top to a wall (use neutral-cure silicone)
- Working with stone sinks (granite, marble—putty can stain)
In those cases, I use Dow Corning 995 or GE Silicone II. But for metal or ceramic drain flanges? Putty still wins.
Warning: Using the wrong putty on a PVC drain → oil migration → pipe softening → sudden crack during pressure test → flooding, structural damage, mold growth → Replace entire drain assembly.
→ Safe alternative: Use only non-oil-based, water-based, or silicone-infused putty on plastic fixtures.
FAQs
Can I use plumber’s putty on plastic drains?
Only if it’s non-oil-based. Oatey Blue, Danco, and SikaFlex are safe. Never use RectorSeal No. 5 or other oil-based putties on PVC, ABS, or polypropylene. The oil can weaken the plastic over time, leading to cracks under pressure. Always check the manufacturer’s instructions on the drain box—many now specify “use silicone only.”
How long does plumber’s putty last?
In ideal conditions, 10–15 years. But I’ve seen it last 20+ on cast iron sinks with no water exposure. In high-use kitchens or steam showers, 5–8 years is more typical. If you notice water pooling under the sink after 3 years, it’s not necessarily the putty—could be loose flange bolts or a warped sink. Always check the hardware first.
Is there a difference between tub and sink putty?
No. The same product works for both. Some brands market “tub putty” as thicker, but it’s usually the same formula. I use Oatey Blue on tubs, sinks, and even bidets. The key is surface prep, not product type.
Can I reuse plumber’s putty?
Not effectively. Once you roll it out and press it into place, the texture changes. Re-rolling it won’t restore its original plasticity. If you remove it, scrape it off and start fresh. Old putty loses its sealing properties. I’ve seen people try to “repack” it—always fails within weeks.
What’s the best way to clean up excess putty?
Use a damp cloth while it’s still soft. If it hardens, gently scrape with a plastic putty knife or old credit card. Never use metal. It scratches porcelain, ceramic, and stainless steel. For stubborn residue, apply mineral spirits on a rag—rinse immediately. Avoid acetone—it can damage finishes.
Can I use plumber’s putty for a toilet flange?
No. Toilet flanges require a wax ring or rubber gasket. Putty is not rated for the weight or pressure of a toilet. Using putty here causes leaks, uneven seating, and eventual floor rot. Always use a standard wax ring or a foam gasket designed for flanges. This is a code violation in many areas.
Final Thought
Plumber’s putty isn’t glamorous. It doesn’t come in a flashy tube. It doesn’t have a TikTok trend. But when you need a seal that breathes, moves, and lasts without bonding, nothing else comes close. Choose the right one. Prepare the surface. Don’t rush. And don’t let your client’s “granddad’s putty” fool you.
Next time you install a drain, remember: the difference between a quiet sink and a dripping nightmare isn’t the tool. It’s the putty.
Sarah Thompson