Best Automotive Seam Sealer: Keep Your Vehicle Free of Rust and Drafts

This brushable product is ideal for adding anti-corrosion protection to your auto’s body if you want to target a large surface area. In less than 60 minutes, it’s completely dry, allowing you to paint on top to cover its gray finish.

Thanks to its waterproof and insulating features, this makes a great option for preventing cold air and rain from entering your vehicle. Plus, it prevents rust and corrosion from forming on your car in the first place.

Due to this type of product, you’ll need to purchase a brush separately, as it doesn’t come with tools. Plus, it dries a gray color, so you’ll need to paint over the result to match your auto’s body.

The 3M Dynatron heavy-duty product is permanently elastic and non-staining, making it ideal if you don’t plan to paint over the surfaces afterward. Apply it to gaps and voids in your vehicle—including the interior and exterior. It’ll reduce the chances of mildew and mold growth.

Its thick consistency makes this a great product to apply as it doesn’t produce any drips. Not all sealers are thick, which can make the application complex. It’s also reasonably priced. 

However, you should consider that the 3M Dynatron product doesn’t come with instructions or a long nozzle, which isn’t ideal for beginners or targeting hard-to-reach areas.

This ACDelco seam filler provides an excellent solution for sealing cracks, while providing a non-staining result that won’t crack. You can also paint over the finished surface just 60 minutes after you’ve applied the product.

It’s quick-drying and has a thick consistency, helping you to apply the solution without it pouring everywhere. Plus, it’s trust-worthy enough to use on panels that have been involved in a collision.

However, avoid using this seam filler near high-temperature objects, as it’s unsafe. Some customer reviews also report that it doesn’t dry as hard as competitor products.

This brushable seam sealer is fast-drying and designed for exclusive use on automobiles. You’ll like how this sealant remains flexible and won’t harden. This flexibility prevents cracking, sinking, and sagging. 

What’s nice about this 30.4 fluid ounce can is that it gives you excellent adhesion to the body while also filling seams, crevices, cracks, and joints. This sealant is waterproof and has insulating qualities. The color of this sealant is grey, and you can paint it in 30 to 60 minutes after application. 

Unfortunately, the consistency of this sealant is thick, requiring you to use a putty knife to apply it instead of an actual brush. The potentially messy application process and quick drying time make this sealant not first-timer friendly.

This one quart can of brushable seam sealer gives you plenty of sealant to work with. You can use it to spot-weld rivets, bolts, and joints. It will permanently adhere to painted and bare surfaces. What’s nice about this sealant is that it matches the OEM grey appearance and color for a clean finished product. 

It will skin over in 10 to 15 minutes and become a flexible and durable bond. After an hour, it will be dry enough to paint over. A nice-to-have quality is that this sealer is made to comply with strict standards for safety and efficiency. 

One downside of this seam sealer is that it comes in a quart can similar to a paint can. This can make it messy to use. You also don’t want to leave the can open for too long, or it will begin to skin over in the can.