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KWIK SUMMARY
Black silicone sealant is a 100% silicone, aquarium-safe adhesive used to bond glass panels on aquariums 55 gallons and larger, giving tanks a clean, uniform look while creating a watertight, fish-safe seal. It resists weathering, temperature extremes, and prolonged submersion, and it's the go-to choice for tanks with black trim or dark backgrounds.
The typical aquarium is carefully constructed to withstand practically any use. These aquariums include black-trim aesthetics and a variety of sizes. The one-piece center-braced frames of large aquariums prevent glass bowing. Black silicone sealants are available for aquariums 55 gallons and more.
The manufacture of freshwater and saltwater aquariums has been the focus of the formulation of Black aquarium Silicon. Without the need for primers, this high-modulus component RTV Silicone Sealant creates solid cohesive connections to glass. The bindings are unaffected by prolonged submersion in water, and once fully cured, they are fish-safe. The non-slump Aquarium safe Silicone Sealant can be used on vertical surfaces without flowing or sagging.
- Low Modulus
- Outstanding tensile strength
- Great primerless glass adherence
- The bond is not damaged by prolonged submersion in water.
- Outstanding clarity
ASI Aquarium Sealant provides great resistance to weathering, including ozone, ultraviolet radiation, and airborne pollutants because it is a 100% silicone sealant.
After curing, ASI Aquarium Silicone Sealant can endure constant operation temperatures of -57°C to +233°C (-70° F to 450°F) and can be applied to surfaces with temperatures ranging from -18°C to +50°C (0°F to +120°F).
Please get in touch with us if you're a manufacturer and would want to see data on the ASI Aquarium Sealant to compare during independent testing. We may send bulk supplies to C of Cs or C of As as well.
What Is Black Silicone Used For?
Beyond aquariums, black silicone sealant is a general-purpose 100% silicone adhesive used anywhere you need a flexible, waterproof, weather-resistant bond that also looks clean and dark.
Technical Characteristics Of Black Silicone Sealant
- Amount: 80 ml
- Size of packaging (L/H/W): 41/183/71 mm Volume of packaging: 0.5 l
- consistency: steady and pasty
- Temperature resistance: -40 to 180 degrees Celsius
- The time needed for skin to form: roughly 10 minutes
- Shore A hardness: approximately 25 (DIN 53.505)
- 1.02 g/cm3 for density
- Curing rate: around 2-3mm/24 hours
- About 1.40N/mm2 for tensile strength (DIN53504)
- About 0.5N/mm2 is the modulus of elasticity at 100% (DIN 53504).
- Break elongation (DIN 53504): approximately 575%
Read More : 5 Easy Fish Aquarium Kit & Water Testing Tips for Summer Care
Completion Of Materials
The glass needs to be free of all dust, debris, and grease for bonding to be successful. The formation of the bond may be hampered by the presence of certain pollutants. Thus, the glass must be cleaned using appropriate and compatible cleaners such as no-ionic solvents, diluted acetic acid solutions, or extremely hot water. The freshly cleaned glass needs to be dried as soon as possible with a clean, lint-free cloth or dried with hot, oil-free air.
The glass should NOT be cleaned with soap and water mixtures. The failure of adhesion might be caused by soap residue acting as a releasing agent.
Clean and dry surfaces should be present on every surface. Before applying a sealer, let the surface completely dry. Avoid using alcohols or oil-containing solvents like Varsol while solvent wiping.
When using ASI Aquarium Silicone Sealant on nonporous surfaces, priming is typically not necessary. It is simple to verify unprimed adhesion by using a small test bead and waiting seven days for maximal adherence to happen. Contact ASI if the primer is required.
Read More : How Long Can Fish Go Without Food?
When Should You Choose Black Silicone Over Clear Silicone?
Both clear and black silicone cure to the same fish-safe, watertight bond. So, the choice usually comes down to looks and where the seal sits on the tank.
Reach for black silicone on a fish tank when:
- The tank has a black trim, black background, or black stand/canopy. Also, use this if you want the seams to blend in rather than draw the eye.
- You're resealing an older aquarium that was originally built with black silicone.
- You're building or repairing a large-format display tank (55 gallons and up), where a clean, uniform black seam reads as more "finished" and professional than a visible clear line against a dark backdrop.
- You want the internal bracing, corner seams, or bottom seal to be less visually distracting once the tank is stocked and lit.
Clear silicone tends to be the better call when the tank has a clear or lightly tinted background, when you're doing a small spot repair and want the patch to be as invisible as possible, or when the surrounding trim and stand are light-colored.
As a rule of thumb: match the sealant color to the tank's existing seams and trim rather than picking one because it's "stronger" chemically; black silicone for aquarium use and clear aquarium-safe silicone perform the same job once fully cured.
Common Mistakes When Applying Black Silicone Sealant
Even a high-quality black silicone on fish tank will fail early if it's applied incorrectly. The most frequent issues are:
- Skipping the cleaning step : Any residue of dust, grease, old silicone, or especially soap will weaken adhesion. Soap film in particular acts as a release agent, so wash with hot water or a diluted acetic acid solution instead.
- Not fully removing old silicone : When resealing, leftover bits of the previous bead prevent the new silicone from bonding directly to glass. Old sealant should be cut and scraped away completely before applying fresh black silicone.
- Applying over damp or wet glass : The surface needs to be completely dry before the bead goes on, or you risk trapped moisture weakening the cure.
- Using the wrong cleaning solvent : Alcohols and oil-based solvents can leave behind residue that interferes with bonding. So, stick to non-ionic solvents or diluted acetic acid.
- Disturbing the seam too early : A skin forms in around 10 minutes, but that's not the same as a full cure. Filling the tank or handling the seam before the silicone has properly cured (allow the full recommended cure time, checking with a small test bead if unsure) can compromise the bond.
- Uneven or inconsistent beads : Rushing the application can leave gaps, air pockets, or thin spots along the seam, which become weak points under water pressure.
- Skipping the adhesion test : On nonporous surfaces, a primer usually isn't needed, but it's still worth running a small test bead and waiting about seven days to confirm adhesion before committing to a full rebuild or reseal.
How Long Does Black Silicone Sealant Last?
Now that you know “what is black silicone sealant used for”, you might be wondering how long it lasts. A properly applied bead of black silicone for aquarium use, on clean glass with no shortcuts taken, can last well over a decade. Many well-built tanks go 10-20 years before a reseal is needed. That said, longevity depends on a few real-world factors:
- Application quality : Bonds made on properly cleaned, dry, grease-free glass last far longer than rushed or contaminated applications.
- Cure time : Full cure (not just the ~10-minute skin) needs to be reached before the tank is filled and put under water pressure.
- Tank size and water load : Larger tanks put more constant stress on seams, so very large aquariums are sometimes resealed proactively even before visible problems appear.
- Environmental exposure : ASI-type sealants resist UV, ozone, and airborne pollutants well, but tanks in direct sunlight or harsh environments may show wear sooner.
- Physical disturbance : Moving a fully set-up tank, impacts, or flexing the frame can shorten the effective life of a seam even if the silicone itself hasn't degraded.
Conclusion
Black silicone sealant does one job exceptionally well : Bonding aquarium glass into a watertight, fish-safe seal that also looks clean against dark trim and backgrounds. Clean and dry your glass thoroughly, and apply an even bead. Also, give it the full cure time before filling the tank. Done right, that seam can outlast a decade of use. However, check corners periodically, and reseal at the first sign of cracking or seepage.
