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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 |
|---|---|---|
| GE Sealants GE5070 Kitchen & Bath Silicone | Best Overall | ~$8 |
| DAP 18401 Kwik Seal Plus | Best for Tubs & Showers | ~$7 |
| Gorilla 100% Silicone Sealant | Best Heavy Duty | ~$10 |
Best Overall: 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
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 paintable after curing. 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
- ✅ Paintable after cure
- ✅ 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.
- Silicone gives off a strong odor while curing and needs good ventilation.
- 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
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 fast cure time — touch-dry in 2–4 hours.
- ✅ 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
Gorilla’s silicone is their strongest formulation — waterproof, temperature-resistant from -65°F to 400°F, and excellent adhesion to virtually any material. Ideal for areas that get extreme temperature swings (around water heaters, near exterior walls) or where you need a permanent bond.
- ✅ Extreme temperature range
- ✅ Permanent bond — very difficult to remove
- ✅ Works on any material
- ❌ Clear only — limited 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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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.
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.
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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