IPS WELD-ON 80100 Soft Seal Stain-Free Plumber's Putty - Lead-Free, Non-Corrosive, and Waterproof,14 oz

What it is and who it’s for

The Soft Seal plumber’s putty from IPS is a straightforward, dependable sealant for creating watertight joints around sink drains, faucet bases, and similar hardware. It’s a non-hardening, lead-free, non-corrosive putty that stays pliable after installation. That combination makes it especially useful for anyone who routinely assembles and services fixtures—DIYers setting a new sink basket or pros who want an easy-to-remove seal on parts that might need attention later.

I’ve kept a 14 oz tub of this on the bench for a few months and used it on several kitchen and bath jobs, plus a couple of oddball tasks around the house. It’s become the default “grab it and go” putty when I want a reliable seal that I can re-open without a fight.

Formulation and handling

Right out of the tub, the putty is soft and ready to work—no warming or oiling required in my experience. It kneads cleanly without sticking to your fingers, and it rolls into consistent ropes with little effort. That matters more than it sounds; a putty that’s too stiff creates gaps, and one that’s too sticky can pull apart as you set the fixture. This one strikes a comfortable middle ground.

The manufacturer calls it waterproof, non-corrosive, and lead-free. Those are table stakes for modern plumber’s putties, but worth noting if you’re sealing metal hardware or fixtures with delicate finishes. It’s labeled as stain-free, which is important for use around light-colored composites and natural materials. In my tests on stainless steel, porcelain, and a white composite sink, it didn’t leave a halo or oil shadow. If you’re working on natural stone, I still recommend checking the fixture and stone manufacturer’s guidance and testing a hidden spot first, as some stones can be finicky.

Odor is mild and not intrusive. Cleanup is simple: trim squeeze-out with a plastic scraper or thumbnail and then wipe with a dry rag. If you want a final polish, a damp rag or a touch of a mild cleaner takes care of any residue.

In use: drains and faucets

The classic use is a basket strainer install. I rolled a 3/8-inch rope, circled the sink opening, dropped the strainer, and tightened the locknut from below. As pressure built, I watched for uniform squeeze-out to confirm coverage. After trimming the excess, the seal looked tidy and even. I ran a full sink test immediately—no drips. I rechecked a week and a month later after plenty of hot/cold cycles: still dry, and the joint remained pliable when pressed from the edge, which tells me the putty didn’t shrink or crack.

Under a faucet base, the putty conformed nicely around the irregularities of the casting and deck. Because it stays soft, you can snug the nuts, check alignment, and adjust without fear of breaking a cured bond. That adjustability is a big advantage over silicone for bases and flanges where you might need to fine-tune orientation.

One practical tip: less is more. It’s tempting to overpack the ring, but a modest bead gives you a cleaner squeeze-out to trim and reduces cleanup time.

Beyond plumbing: handy as a draft stop

While this is a plumbing product, I’ve also used it to seal a small wall penetration behind a thermostat where wire holes were letting wall cavity air influence the temperature reading. A pea-sized amount pressed into the opening stopped the draft without hardening, so it can be removed later if I need to pull the wire. It’s not a replacement for fire-rated or expanding sealants where those are required, but for small, non-critical gaps, the always-pliable nature is handy.

Performance over time

The main promise here is that it won’t harden, shrink, crack, or crumble. After months in place on a kitchen basket strainer and a lavatory drain, that promise has held up. I’ve pulled hardware to inspect out of curiosity: the putty remained soft and could be re-compressed to re-seat the fixture without needing a new bead. That reusability isn’t infinite—if the bead is contaminated with grit or torn up during removal, I replace it—but it speaks to the formulation’s consistency.

Waterproofing is reliable, provided your joint is properly assembled and tightened. Remember that plumber’s putty is a sealant, not a structural adhesive. It fills micro-gaps between mating surfaces; it won’t compensate for warped flanges, misaligned parts, or overtightened plastic fittings that have deformed.

Where it shouldn’t be used

• Pressurized connections: Don’t use putty on threaded water supply lines, valves, or any pressurized joint. Use thread sealant or PTFE tape as specified.
• Manufacturer exceptions: Some sink and drain manufacturers specify silicone or a gasket. Follow their guidance to avoid warranty issues.
• Natural stone caution: Although labeled stain-free, always confirm compatibility with marble, granite, or other porous stones, and test first. Some installers prefer silicone on natural stone for absolute peace of mind.
• Moving joints or expansion gaps: For joints subject to significant movement, a flexible sealant like silicone is a better fit.

Color and finish

Expect a light gray/off-white rather than a bright white. Under metal flanges and sink rims, you won’t see it after cleanup, but if you’re counting on a pure white bead to remain visible, this isn’t that. I prefer the understated, neutral tone—it hides well under trims.

Storage and longevity

The 14 oz size is generous for homeowners and a reasonable shop stock for pros. Like any putty, it can firm up if the lid is left loose or it lives in a very dry environment. I keep the lid seated firmly and sometimes press a piece of plastic wrap onto the surface before closing the container, which helps maintain freshness. If it does feel a bit stiff, kneading it in warm hands usually brings it back. If a tub ever arrives truly dry or crumbly, that’s a storage/age issue, not typical behavior—get a fresh one.

Comparisons and alternatives

• Versus silicone: Silicone forms a permanent, flexible, water-tight bond and is often required by some fixture makers. It’s messier, harder to clean, and disassembly later is more work. I use silicone for undermount sinks, tub surrounds, and visible seams that move. I use this putty for basket strainers, faucet bases, and drains where serviceability is valuable.
• Versus wax or gaskets: Rubber gaskets and wax rings have specific use cases. If a fixture ships with a gasket that’s designed for the job, I’ll use it. Putty still earns a place when gasket surfaces are imperfect, or when I want the insurance of a conforming seal beneath a metal flange.

Small usability touches

• Workability: Easy rolling and placement, even in cool garages. It doesn’t slump off vertical flange edges as you set hardware.
• Cleanup: Fast, no haze, and forgiving if you need to lift and reseat before final tightening.
• Non-corrosive: No tarnish or surface etching around brass and stainless trim in my installs.
• Service-friendly: Because it never fully hardens, removing hardware months later is painless and leaves less residue than silicone.

The bottom line

The Soft Seal plumber’s putty does exactly what I want from a non-hardening sealant: it forms a reliable, waterproof seal around drains and faucet bases, stays workable for adjustments, cleans up easily, and remains soft over time so future service is straightforward. The consistency is user-friendly, the formulation plays nicely with common fixture materials, and the 14 oz tub is a practical size to keep on hand.

A couple of caveats apply. Don’t expect a bright white color; it’s a neutral gray/off-white. And while mine has stayed fresh in the tub, you’ll want to keep the lid sealed tightly to preserve that softness. As with any putty, respect the limitations—no pressurized joints, follow manufacturer instructions, and take care around natural stone.

Recommendation: I recommend it. If you need a dependable, non-staining, non-hardening putty for faucet bases, basket strainers, and similar fixtures, this one strikes an excellent balance of workability, clean finish, and long-term performance. It’s become my default choice for routine plumbing seals where serviceability matters.