The 5 Best Flexible Seam sealers (2023 reviews)

Not everyone likes to purchase sealer for their daily usage, but the 3m flexible seam sealer would be an anomoly. The M Flexiclear body seam sealer creates strong, airtight seals on exterior and interior joints & seams. This product adheres to the metal & remains slightly flexible after it dries (like an elastomeric caulk) so it won’t crack away from the metal as the vehicle heats & cools in the sun or flexes as it’s driven.

This is a low modular sealer, a formulation which offers more elasticity for applications where flexibility is required. It takes a while to dry but works good. This stuff dries pretty hard and with no flex. It is easy to spread with gloves or a paint brush. It is great for replacing the old dried up sealer.

Why We Like This:

Fully cures in a few days to a flexible tan coating
Low modular sealer stays flexible once cured
Wash surface with soap and water to remove water soluble contaminants

Best For seams: 3M Seam Sealer

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The 3m seam sealer should be able to handle its purpose and duties with ease. Whether you're protecting your hardwood floors from paint splatter or going all out with a decorative mural, rely on scotch delicate surface painter's tape for a professional look that's easy on your surfaces. The 3M Urethane Seam Sealer, 08368 can be sanded, however sanding this will not leave you with a fine finish such as body filler. It is designed to be used over epoxy or urethane based primers, and the sealer comes in several colors to enable color matching. It can be smoothed to a featheredge or brushed.

It comes with two tips and also comes with one nozzle. It is easy to apply, dried quickly, and very firm once dry. It adheres well to both painted or primed or bare metal however adhesion is reduced if adhering to a self etching primed surface.

Why We Like This:

Super easy flowing, urethan based sealer
Perfect consistency for filling in gaps in body panels
Cleaned up easily with mineral spirits
Must be clean unpainted surface for proper bonding to take place

Best For Plastic: custom shop Flexible Seam Sealer

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The custom shop flexible seam sealer should be able to handle its purpose and duties with ease. If you want it to look smooth apply with a small brush once you get the seam covered with rubber gloves and put some thinner on your finger rub sealer lightly one way. It is fast drying and designed exclusively for automotive uses. It provides excellent adhesion, seals cracks, crevices, body seams and is ideal for use on all lap and flange seams and joints. It is easily applied with a brush and holds a perfect brush mark to match that o.e.m.

It is easy to apply and clean up on unwanted areas. The package is completely unharmed and even has padding inside to prevent damage. It is easy to apply with a flexible putty knife.

Why We Like This:

Seals up the metal seams very well
Fast drying, use a puddy knife, or plastic spreader
Easy to handle, works well, and paintable

Best For Fiberglass: Evercoat Flexible Seam Sealer

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Next on the list, we've got yet another sealer that manages to win our hearts. It's the evercoat flexible seam sealer and it's widely considered as one of the best convenient sealer you can buy. The Caulking Tube Seam sealer is easier to work with. It spreads easy and is much smoother to work with than Eastwood or SEM. If you are putting it between overlapping metal, it dries pretty solid. It is great to brush on metal auto body joints and paints out great. It is also for sealing metal body seams. If you use it straight out of the can it sets up really good in 8to 10 hours and is paintable close to the factory sealer. It is the perfect consistency. It is easy to work with, dry in a couple of minutes.

Why We Like This:

Spreads easy with a stiff brush
Hardened quickly and there were no problems painting over the sealer
Excellent product but requires acetone to clean brushes
Works just great for sealing up where you have welded at

Best Quality Sealer: SEM Flexible Seam Sealer

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The sem flexible seam sealer is capable of outshining several other sealer featured in this list in overall features for the price point. The Sem 29382, beige seam sealer is a flexible, non sag seam sealer for interior and exterior seams, joints, and voids that will not shrink, crack, chip or discolor. It works well and paints over nicely. It can be smoothed a f tooled for some time which is nice.

It fits a standard size caulking gun. It is very difficult to remove and has to be cut off with a knife, so excellent adhesion. The Sem seam sealer requires no cure time before painting or priming. It goes on like regular RTV or Caulk but dries to a hard rubbery consistency.

Why We Like This:

Delivers what they promise
Good investment for long term