Are there so many types of sealants? Teach you how to choose the right one in one minute!

There are many types of sealants, with different performances and prices. If you choose the wrong type, the effect may be poor at best, or it may completely fail or even damage the substrate. Only by understanding the core differences and “prescribing the right medicine” according to the application scenario can you spend your money wisely and ensure that the project will be worry-free for a long time.

Core skills: clarify needs, understand characteristics, and match substrates

Silicone Sealant:

Characteristics: Excellent elasticity (high displacement ability), optimal weather resistance (ultraviolet rays, high and low temperatures), long life, and excellent waterproofness. There are many types of subdivisions.

Common types and uses:

Acid glue (vinegar smell): General type, cheap. Good for bonding glass, ceramics, and metals. Corrosion of marble, cement, and metals (especially copper and iron)? Use with caution! Fast curing.

Neutral glue (odorless/alcohol): Most commonly used! Non-corrosive, suitable for a wide range of substrates (stone, concrete, aluminum plate, glass, most plastics, painted surfaces). There are deacetoxime type (alcohol smell), dealcohol type (slight odor or no odor), deamidation type, etc. It has good weather resistance and waterproofness, and is commonly used in kitchens and bathrooms.

Anti-mold glue: Add high-efficiency mildew inhibitors, a must for kitchens, bathrooms, and humid areas! Look for ASTM G21 or similar mildew resistance grades (0 is the best).

Structural adhesive: Ultra-high strength (bonding + body strength), used for curtain wall structure bonding and other load-bearing/wind pressure-resistant parts. Professional design and construction are required.

Disadvantages: Generally cannot be covered with paint; the surface is easy to absorb dust; the price is relatively high.

Polyurethane Sealant (PU):

Features: High elasticity, high strength, good wear resistance, and paintability (partially paintable). Good weather resistance, but long-term UV resistance is usually not as good as silicone. Non-corrosive.

Application: Building expansion joints, concrete joints, metal roofs, automobiles, carpentry (caulking and bonding). Especially suitable for occasions that need to withstand dynamic loads (such as vehicle rolling) or subsequent painting.

Disadvantages: Slow curing; resistance to moisture and heat aging may be slightly inferior; single component requires moisture curing (pay attention to deep seams); some products are prone to blistering; sensitive to moisture (storage, construction).

Modified silane glue (MS Polymer Sealant, also known as silane modified polyether glue):

Features: Environmentally friendly, non-toxic and odorless (extremely low VOC), non-corrosive. Excellent comprehensive performance: good elasticity, high strength, good weather resistance and aging resistance, and a wide range of bonding substrates (including difficult-to-bond plastics PP/PE, oily metal surfaces). Excellent paintability (easy to paint). Moderate curing speed.

Application: Widely used, especially suitable for occasions with high environmental protection requirements, complex substrates (such as automobiles, containers, prefabricated buildings), and the need to paint. It is an excellent substitute for silicone and polyurethane.

Disadvantages: The price is usually the highest.

Acrylic Sealant (latex type):

Features: Paintable (mainly water-based paint), solvent-free, more environmentally friendly, and inexpensive. Mainly used indoors.

Applications: Filling gaps between door and window frames and walls (indoor side), skirting, gypsum board joints (need to be used with joint tape), and filling small cracks. Not water-resistant, poor elasticity, easy to crack, not suitable for kitchens, bathrooms, and outdoors.

Disadvantages: Poor water resistance, low elastic displacement capacity, easy to crack and powder, and short outdoor life.

💡 Key points: There is no universal glue! Ask three questions before buying: 1. Where is it used? (Indoor/outdoor/kitchen/expansion joints…) 2. What to stick? (What is the material of the substrate? Compatibility?) 3. What do you want? (Elasticity? Strength? Weather resistance? Mildew resistance? Paintable?) Choose accurately based on the answers.