For plumbing fixtures, use 100% silicone, not painter’s caulk. GE Sealants GE5070 Kitchen & Bath Silicone is the pick for most sinks, tubs and toilet bases: it is 100% waterproof, water-ready in about 30 minutes, and mold resistant. DAP Kwik Seal Plus is the easier one to tool if you want a paintable finish.
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Silicone sealant is the finishing touch on almost every plumbing installation — around tub and shower surrounds, at sink bases, around toilet bases, and anywhere water could work its way behind a fixture. Using the wrong sealant or applying it incorrectly leads to mold, water damage, and failed seals within months. Here’s what actually holds up.
| Product | Best For | Price tier |
|---|---|---|
| GE Sealants GE5070 Kitchen & Bath Silicone | Best Overall | Mid |
| DAP 18401 Kwik Seal Plus | Best for Tubs & Showers | Lowest |
| Gorilla 100% Silicone Sealant | Best Heavy Duty | Highest |
Best OverallEditor’s Choice
GE Sealants GE5070 Kitchen & Bath Silicone
100% silicone · 100% waterproof · water-ready in 30 min, full cure 24 hr · 10-year mold-free product protection · not paintable · white
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GE’s kitchen and bath silicone is 100% silicone — not silicone-latex hybrid — which means it doesn’t shrink, doesn’t crack in temperature changes, and holds its seal indefinitely in wet environments. It’s mold and mildew resistant, and because it is 100% silicone it will not take paint — the color you buy is the color you keep. I use GE or equivalent 100% silicone on professional jobs and it’s what I recommend to homeowners.
- ✅ 100% silicone — no shrinking or cracking
- ✅ Mold and mildew resistant
- ✅ Water-ready in 30 minutes
- ✅ Adheres to tile, porcelain, glass, metal
- ❌ Takes 24 hours to fully cure
- It is 100% silicone and 100% waterproof, so it holds up in showers, around sinks, and other constantly wet areas.
- It is water-ready in about 30 minutes and fully cures in 24 hours, which keeps small repairs moving fast.
- It carries 10-year mold-free product protection and stays permanently flexible without cracking.
- It is not paintable, so it only works where the silicone color is the final look.
- Its maximum gap fill is 3/8 in., so it is not for wide joints.
- Tooling and cleanup require a solvent like mineral spirits rather than just water.
Verdict: Best for wet, high-use kitchen and bath joints where a durable, waterproof, mold-resistant seal matters more than paintability.
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Best for Tubs & Showers
DAP Kwik Seal Plus
siliconized acrylic (latex) caulk · Microban antimicrobial protection · 100% waterproof & crackproof · paintable · soap-and-water cleanup · white/clear
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DAP’s Kwik Seal Plus is specifically formulated for the high-humidity, frequently wet environment of tubs and showers. The siliconized acrylic formula is easier to tool (shape with a wet finger) than pure silicone, and it remains flexible long-term. Strong mold resistance, and it skins over fast: DAP’s data sheet gives a 15-minute tack-free time. Full cure is much slower, and the clear version dries clear over 7 to 14 days.
- ✅ Easier to apply and tool than pure silicone
- ✅ Fast touch-dry time
- ✅ Strong mold resistance
- ✅ Good for caulking around tub deck and shower pan
- ❌ Not as durable as 100% silicone long-term
- It is paintable and cleans up with just water, making it forgiving for DIY tub and shower work.
- It includes Microban protection that fights stain- and odor-causing bacteria, mold, and mildew on the caulk.
- It adheres to ceramic, porcelain, glass, fiberglass, and most plastics.
- It is a siliconized acrylic caulk, not 100% silicone, so it is generally less durable in constantly submerged areas.
- DAP advises waiting about 18 hours before water exposure, longer than pure-silicone options.
- Its one-year warranty is shorter than the multi-year guarantees on premium silicones.
Verdict: Best for tub and shower joints where paintability, easy water cleanup, and built-in antimicrobial protection matter.
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Best Heavy Duty
Gorilla 100% Silicone Sealant
100% silicone · 100% waterproof · water-ready in 30 min, full cure 24 hr · mold & mildew resistant · won’t yellow, shrink or crack · meets ASTM C-920 · clear/white
Check the Gorilla 100% Silicone Sealant price on Amazon →
Gorilla’s silicone is their strongest formulation — waterproof, rated to ASTM C-920 Class 35 for movement, and excellent adhesion to virtually any material. Ideal for joints that move or where you need a permanent bond.
- ✅ Meets ASTM C-920, Class 35
- ✅ Permanent bond — very difficult to remove
- ✅ Works on any material
- ❌ Clear and white only — no other color options
- It is 100% silicone and 100% waterproof, ready for water exposure in as little as 30 minutes.
- It meets the ASTM C-920 standard and stays flexible without yellowing, shrinking, or cracking.
- It is mold and mildew resistant and works across kitchen, bath, window, door, plumbing, and marine uses.
- It is not paintable, so it must be applied where the silicone color is acceptable as-is.
- The cured surface still needs regular soap-and-water cleaning to prevent surface mold growth.
- Full cure takes 24 hours and slows further in cold, humid, or large-bead conditions.
Verdict: Best for heavy-duty, high-movement seals that need maximum waterproofing and flexibility across indoor and outdoor jobs.
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Silicone is one of four sealants a homeowner runs into. For where each belongs, see tape vs pipe dope vs putty — it covers the joints silicone should never touch.
What Silicone Sealant Is Best for Plumbing Fixtures?
Around fixtures — sink bases, tub and shower surrounds, toilet bases — the right product is 100% silicone. It does not shrink or crack with temperature swings and it holds its seal in constantly wet places. GE5070 is the one to reach for; a siliconized acrylic like DAP Kwik Seal Plus trades some of that durability for paintability and water cleanup.
Silicone or Plumber’s Putty Around a Sink Drain?
Under a metal sink drain or basket strainer, plumber’s putty is the usual choice: it is a non-hardening, non-adhesive bedding compound, so the strainer comes back out cleanly years later. Reach for 100% silicone instead on natural stone and most plastics, where oil-based putty can stain or craze. Our plumber’s putty guide covers that side.
How to Apply Silicone Sealant Correctly
- Remove all old sealant completely — use a utility knife and silicone remover. New sealant won’t bond over old.
- Clean the surface with rubbing alcohol and let it dry completely.
- Apply painter’s tape on both sides of the joint for a clean line.
- Cut the caulk tube nozzle at a 45-degree angle — small opening for thin joints, larger for wide gaps.
- Apply in one smooth continuous bead.
- Wet your finger with soapy water and smooth the bead in one pass.
- Remove the tape immediately before the sealant skins.
- Allow to cure fully before exposing to water.
Plumber’s tip: The most common mistake is applying new sealant over old. It won’t stick and it’ll fail within months. Remove everything first, even if it takes an hour.
The tool that makes step 1 bearable: a dedicated caulk tool scrapes cured sealant out of a corner and tools the new bead to an even profile, so the removing and the finishing happen with one thing in your hand. The ALLWAY CT31 3-in-1 caulk tool has a stainless-steel blade for the removal and a rotatable silicone tip for the bead. A utility knife and a wet finger do the same job for nothing, so skip it if you are resealing one joint — it earns its place when you are stripping a whole tub surround and your thumb gives out halfway along.
FAQ
What’s the difference between caulk and silicone?
“Caulk” is a general term for gap-filling sealants. Silicone is a specific type of caulk — the most water-resistant and durable for plumbing applications. Never use standard painter’s caulk in wet areas.
How long does silicone sealant last?
Properly applied 100% silicone lasts 10–20 years. The sealant around a tub or shower should be inspected annually and replaced at the first sign of cracks, separation, or discoloration.
Can I apply silicone over existing silicone?
No. New silicone will not bond to cured silicone. Remove all existing sealant before applying new.
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Bottom Line
GE5070 100% Silicone is the professional standard and the right choice for most applications. DAP Kwik Seal Plus is easier to work with if you’re doing a tub surround and need a clean finish. Either way — clean the surface completely before applying, and don’t rush the cure time.
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