10 Best Marine Sealant For Aluminum Boats of December 2025

• USE WHAT THE PROS USE – Extremely strong adhesive sealant retains strength above or below waterline
• BONDS PERMANENTLY – Ideal for sealing, bonding and attaching on the interiors of boats and RVs, or on exteriors below the waterline and where shielded from the sun
• LONG LASTING FORMULA – Tough polyurethane polymer resists weathering and salt water
• WON’T CRACK OR PEEL – Stays flexible, retaining strong bonds even during vibration, structural movement or shock
• EASY TO APPLY – Adhesive sealant requires no mixing, cures completely in 5-7 days

3M

• DEVELOPED SPECIFICALLY AS A MARINE SEALANT – Stays tough and flexible for a wide range of uses above the waterline
• VERY VERSATILE – Works on metal, glass, paint, fiberglass and more
• EASY TO USE – Applies right from the container with no mixing required
• HELPS KEEP WATERCRAFT LOOKING SHARP – Resists temperatures and mildew, and won’t turn yellow over time
• EASY TO USE – Requires no mixing and cures in as little as 24 hours so you can get back out on the water faster

3M

• Easy to use – just pour, stir and apply
• Tough – reinforced with Kevlar fibers for superior strength
• Practical – enables boats to glide smoothly over debris and rocks
• Fast drying – sets and dries completely in 10-12 hours , waterproof
• Seals small leaks and splits in a single coat
• 2 lb. kit covers approx. 20 square ft. depending on porosity of surface and thickness applied.
• Superior, waterproof epoxy sealer that will protect boat bottoms or truck beds
• Cures to a thick, smooth, black graphite coating
• Reinforced with Kevlar fibers for extra strength
• Bonds to aluminum, steel, fiberglass and wood

Amazing GOOP

• CURES FAST One-part adhesive sealant requires no mixing, typically cures in as little as 24 hours so you can get back on the water faster
• SEALS ABOVE AND BELOW WATERLINE – Ideal for joints, rub-rails, access plates and other areas shielded from the sun
• LONG LASTING FORMULA Tough polyurethane polymer resists weathering and salt water
• WON’T CRACK OR PEEL – Stays very flexible, retaining strong bonds even during vibration, structural movement or shock
• ALLOWS FOR DISASSEMBLY WITHOUT DAMAGE – Medium-strength, semi-permanent adhesive sealant allows for bonded parts to be removed after prolonged use

3M

• Permanent bonding – above and below the waterline
• Fastcure version of 3M Marine Adhesive Sealant 5200
• Tackfree in 12 hours and typically cures within 48 hours
• Tough and flexible polyurethane polymer forms strong bonds
• Capable of retaining strong bonds during vibration, swelling, shrinking or shock

3M

• Easy to apply – One-part adhesive sealant requires no mixing, cures completely in 5-7 days
• Use what the pros use – Extremely strong adhesive sealant retains strength above or below waterline
• Tough, flexible bonds – Stays flexible, retaining strong bonds even during vibration, structural movement, swelling, shrinking or shock
• Bonds permanently – Ideal for sealing, bonding and attaching on the interiors of boats or on exteriors where shielded from the sun
• Long lasting formula – Tough polyurethane polymer resists weathering and salt water

3M

• Gluvit barrier coat seals and protects hulls and decks
• Provides superior protection for fiberglass, wood, aluminum, and steel
• Seals leaky seams and rivets in aluminum hulls, and leaks around fiberglass cabins or decks
• Hard protective coating flexes with hull movements to bridge and seal hairline cracks
• Fills minor cracks and pinholes
• Note:Epoxy Sealer” is 1.8 pounds. and the Gluvit Catalyst” is .268 pounds.

Travaco

• CURES FAST – One-part adhesive sealant requires no mixing, typically cures within 48 hours so you can get back on the water faster
• USE WHAT THE PROS USE – Extremely strong adhesive sealant retains strength above or below waterline
• BONDS PERMANENTLY – Ideal for sealing, bonding and attaching on the interiors of boats and RVs, or on exteriors below the waterline and where shielded from the sun
• LONG LASTING FORMULA – Tough polyurethane polymer resists weathering and salt water
• WON’T CRACK OR PEEL – Stays flexible, retaining strong bonds even during vibration, structural movement or shock

3M

• USE WHAT THE PROS USE – Extremely strong adhesive sealant retains strength above or below waterline
• BONDS PERMANENTLY – Ideal for sealing, bonding and attaching on the interiors of boats and RVs, or on exteriors below the waterline and where shielded from the sun
• LONG LASTING FORMULA – Tough polyurethane polymer resists weathering and salt water
• WON’T CRACK OR PEEL – Stays flexible, retaining strong bonds even during vibration, structural movement or shock
• EASY TO APPLY – Adhesive sealant requires no mixing, cures completely in 5-7 days

3M

• Easy-to-use, two-part, flexible, waterproof epoxy sealer repairs leaking rivets and seams, and patches small holes on aluminum boats quickly and effectively.
• Long working time (75 minutes @ 72°F) ensures better penetration and a better seal. Absorbs stresses from contraction, vibration, shock, and expansion holding firmly to prevent leaks.
• Can be applied to properly prepared aluminum surfaces when the air and substrate temperature is as low as 40°F.
• Resin and hardener come in a single cartridge and are dispensed automatically at the proper ratio. No mixing. No mess to clean up.
• Available in a handy 250 ml. cartridge that conveniently fits standard caulking guns. Includes 2 static mixing tips.

TotalBoat