The 10 Best Gasket Sealers of 2021

Jerry Wilson
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Finding the best gasket sealer for your needs can be surprisingly difficult, but it’s not impossible!

Here’s a quick rundown of the top 10 best gasket sealers available on the market today, and a link to an in-depth product review for each one. Use this guide if you’re evaluating sealer for a specific application.

Clearly, there are plenty of options. Feel free to skip around.

Not sure what gasket sealers are? Be sure to read the gasket sealer definition first.

NameCategoryProduct
Gasgacinch 440-A Gasket Sealer and Belt DressingBest OverallGasgacinch 440-A Gasket Sealer and Belt Dressing
Permatex 81160 High-Temp Red RTV Silicone GasketBudget PickPermatex 81160 High-Temp Red RTV Silicone Gasket
Steel Seal Blown Head Gasket Fix Repair SealerUpgrade PickSteel Seal Blown Head Gasket Fix Repair Sealer

1. Gasgacinch 440-A Gasket Sealer and Belt Dressing

Our rating: 9 / 10

Gasgacinch 440-A Gasket Sealer and Belt Dressing

Check Price on Amazon

Pros:

  • Highly effective
  • Value package
  • Great for cleaning and sealing vinyl seats

(Pack of 2)

Gasgacinch 440-A gasket sealer and belt dressing differs from the slew of other automotive chassis lubricants on the market with its thickness and tacky texture. It’s designed to bond with rubber, vinyl, and silicone gaskets. This product builds-up a sealing layer that’s extremely resistant to extreme heat or cold, making it a great option for use in cold-climate environments that are susceptible to freezing.

The highly effective chassis dressing and sealer also prevents wind, water, and debris from seeping through tightly sealed areas that are prone to wear. The 440-A formula works well on vinyl seats as it rejuvenates the vinyl and protects it from dirt and spills. A nice bonus are all the verbal compliments you’ll receive about how great your car’s interior looks.

2. Permatex 81160 High-Temp Red RTV Silicone Gasket

Our rating: 9 / 10

Permatex 81160 High-Temp Red RTV Silicone Gasket

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Pros:

  • Been around for years
  • FDA approved
  • One of the most popular RV gasket sealers out there
  • Heat resistant
  • Comes in a 3oz tube, requires a tiny amount to create a seal

Permatex is one of those brands that I always buy, whether I’m fixing a leak on a car or tightening gaskets on my RV.

The heat resistant formula that Permatex uses in their gasket sealers makes them an excellent choice for sealing around the pipes of your RV. RV pipes tend to be exposed to direct sunlight for long hours, making the pipe walls hot sometimes, and this is where Permatex adds value.

This silicone gasket sealant has been around for a while and is one of the most popular products used by RV owners to seal around the pipes. The 3oz tube is supposed to be enough for many applications.

3. Permatex 80062 High Tack Gasket Sealant

Our rating: 9 / 10

Permatex 80062 High Tack Gasket Sealant

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Pros:

  • High tack sealant
  • Remains flexible
  • Leak-proof

In case you’re wondering how to permanently seal brake fluid reservoirs, oil coolers, radiator bleeder valves, and similar applications, you might want to check out Permatex 80062 High Tack Gasket Sealant. 50 years of actual testing and production have gone into making this one of the best gasket sealants that you will ever find.

Just like its name says, this caulking is very high-tacking, which means that it will quickly seal up any leaks and you won’t have to worry about them for a long time. In addition, thanks to the properties of Permatex 80062, this caulking will retain its flexibility even as it is exposed to temperatures as low as -46 degrees Fahrenheit.

Another great thing about this caulk is that it remains moisture-resistant, so the risk of rust forming within the gasket should be considerably smaller. Once this sealant is applied properly, it will keep leaks away, and you will be able to enjoy a secure seal for a very long time.

4. Edelbrock 9300 Gasgacinch Gasket Sealer

Our rating: 9 / 10

Edelbrock 9300 Gasgacinch Gasket Sealer

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Pros:

  • No hardening over time
  • Easy to clean residue
  • Versatile
  • Affordable
  • Easy to apply/remove without residue build-up
  • Durable

Cons:

  • Can’t be used on rubber seals
  • Some original positive reviews were caught on counterfeit websites

The Edelbrock 9300 is the best gasket sealer we could find. While there are "gasket goop" alternatives that can be used to fix engine leaks such as Vaseline, SAE50, or a beeswax and petroleum jelly mixture, they have a tendency to harden over time. This gasket sealer is made on a non-hardening basis, so there are no problems if you happen to wait a few days before working on your engine.

Edelbrok’s 9300 formula is made using butyl, which is flexible even in freezing temperatures. The gasket sealer is a common choice amongst engine builders because of its versatile application, but there are many opportunities for using it outside of the engine.

5. 3M High Temp Black Silicone Gasket

Our rating: 8 / 10

3M High Temp Black Silicone Gasket

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Pros:

  • Good price point
  • Good for motorized vehicles
  • Fits: gas and diesel vehicles, jet skis, outboard motors, and similar watercraft
  • Clearance item

Buyers of this gasket sealant said that their purchase came in a timely fashion with good packaging.

They were able to use this product successfully for simple vent sealing and flange gasket replacement.

It is NOT a PVC based sealer. Read instructions and be sure to use in a well ventilated area.

6. Bar's Leak HG-1 HEAD SEAL Blown Head Gasket Repair

Our rating: 7 / 10

Bar's Leak HG-1 HEAD SEAL Blown Head Gasket Repair

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Pros:

  • Fixes leaks and prevents blow-outs under pressure
  • Increases coolant flow
  • Compatible with conventional and synthetic oils
  • Pleasant strawberry scent

Cons:

  • Can cause sludge in your engine
  • Needs to be added to oil to work properly

The Bar’s Leak HG-1 is my top pick as it’s a highly-effective gasket sealant for blown head gasket repairs and blown head gasket prevention. It’s a petroleum-based product that’s available in syringes or bottles, but you’ll want to go with the HG-1 Head Seal blown head gasket repair kit if you’re going to seal your gaskets on the sidelines.

7. Bar's Leaks 1111 Block Seal Permanent Head Gasket Fix 24 oz.

Our rating: 7 / 10

Bar's Leaks 1111 Block Seal Permanent Head Gasket Fix 24 oz.

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Pros:

  • Permanent head gasket fix
  • Leak prevention
  • Easy to use
  • Ease of installation
  • Recommended by well-known mechanics
  • Leak protection

Cons:

  • Not recommended for use on flat repairs
  • Might require cleaning for big clogs

If you had to choose one tool to keep on hand to fight the never-ending battle of trying to avoid expensive towing costs and car breakdowns, this should be your first choice. The Bar’s Leaks Block Seal is a permanent head gasket sealer that is specially designed to make repair shops obsolete.

8. Steel Seal Blown Head Gasket Fix Repair Sealer

Our rating: 7 / 10

Steel Seal Blown Head Gasket Fix Repair Sealer

Check Price on Amazon

This is one of the best sealant for blown head gaskets of the year. I think it’s the best product. It’s a zinc based sealant that bonds and seals the blown head gasket. It’s pretty easy to use.

You’re supposed to apply it and let it set for 10 minutes. The cool thing is that you don’t have to remove the head or any of the engine parts. You can just run the engine to get some heat and pressure to apply the sealant.

Each bottle contains 16oz of product, so you will have some left over. The product works well and it’s easy to use, so that’s why I like it.

9. BlueDevil Head Gasket Sealer

Our rating: 7 / 10

BlueDevil Head Gasket Sealer

Check Price on Amazon

Pros:

  • Capable of sealing multiple parts
  • Easy to apply
  • Affordable
  • Convenient to apply for non-professionals
  • Reliable brand
  • No need for special tools or training

The BlueDevil head gasket sealer is a well-known brand that has proven its effectiveness in the automotive industry for many years. BlueDevil is one of the most commonly used adhesive sealers for head gaskets, which are a key component in car engines. This means that the BlueDevil brand already has significant credibility with automotive professionals.

Like other adhesive sealers, BlueDevil is a liquid and works by penetrating the surfaces it is applied to. It is very easy to puncture the can, which makes the application process a breeze. However, this sealer should be applied to a sufficiently clean surface. This sealer is incredibly sticky, so you will want to spend adequate time cleaning the area that you are going to seal before you coat it with this sealer.

BlueDevil also makes another sealer, the BlueDevil SuperSealer, which is designed to seal metal to rubber, instead of metal to metal. This sealer is a bit more viscous and takes longer to penetrate the surfaces that it comes into contact with, making it a little less convenient to apply.

10. K&W 401232 Permanent Head Gasket & Block Repair

Our rating: 7 / 10

K&W 401232 Permanent Head Gasket & Block Repair

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Pros:

  • Packaged in a sturdy plastic bottle
  • Versatile, effective, and compact
  • Works well on gas inserts, heater cores, oil pans, or on engines
  • Oil resistant, resists combustion pressure, and won’t damage seals

Cons:

  • May need to thin to get the right consistency for the job
  • Instructions are hard to understand and follow

K&W’s 401232 Permanent Head Gasket & Block Repair is a no-nonsense gasket solution that works on a myriad of tasks from repair to prevention and is truly a universal product. The consistency is a bit thick, so you may need to thin it with light oil. The other issue is that the instructions are confusing. If you can find a video by RWD K&W online, it is well worth watching to see the steps it takes to properly repair a head gasket.

The one gallon bottle is a bit pricey, but the product should last a long time and can be used on a number of items.

Frequently Asked Questions (FAQ)

What is the best gasket sealer?

If you're thinking about selling your home, one of the biggest home fix-it jobs is likely new door and window gaskets. You might be tempted to replace the old gasket with a quick-fix DIY job using duct tape or even an old sock. But doing so is extremely risky and could cost you thousands in damage.

A faulty door or window gasket can cost you big time in energy bills. When a house is properly sealed, it stays warmer in the winter and cooler in the summer. A study conducted by the Department of Energy in the early 1980's found that replacing gaskets can decrease heating and cooling costs by up to 35%.

Additionally, a faulty gasket can cause air leakages and moisture condensation to form, which can cause some serious damage over time. For example, the condensation can form a mold colony, causing serious health issues for you and your family.

What is the best head gasket sealant on the market?

The company claims that you can use Goop gasket maker on head gaskets, among other applications, which is what sold us on this product. We could tell right away that this was a great silicone sealant and that we were probably going to consider this the best head gasket sealant on the market.

We found that it had a great viscosity and was easy to use. We especially liked the texture and the ability to hold onto it. We could flip the tube upside down, squeeze out a bunch of the gasket goop, and then stick our finger on top to keep it from oozing out. This was especially helpful when we needed to keep the tube upside down for too long of a time.

Do head gasket sealers really work?

If you want to learn why and how you should use a gasket sealer in your car, then read our detailed guide about it – here. If you don't feel like reading an entire article on the subject, then just know that it's 100% necessary to use a gasket sealer before you re-install those head bolts. If you don't use it, you might as well rebuild the engine and replace all the valves since you'll just strip those heads out the next time you remove them again.

When it comes to gasket sealers, there's really only one product that you should be considering – Start Rite's 120500 Formula Gasket Sealer. We can't say that it's the best gasket sealer on the market, but it's the only one we'd ever recommend to our readers. It's also the recommended product by most major engine specialists and it can also be found in many auto supply stores.

Will Stop Leak fix a blown head gasket?

Though the product is marketed for use in small engines, many Amazon reviewers have been using the product successfully to repair leaking head gaskets, flooded engines, and even blown head gaskets. The product works by clamping down and ensuring that no more fluids can escape – which is perfect for a head gasket issue.

It’s worth noting that this product is not designed for a vehicle with a blown head gasket. The blown head gasket means that the gasket has already given out, and your engine oil is leaking through the crack. In this case, you probably need a new head gasket, and the Stop Leak product won’t convert a blown head gasket into a fixed one.

Conclusion

If you are looking for a quality sealant, then it is our opinion that the Outland 90040 or the Ultra Tech Red Label will suit your needs nicely. We realize that there are more sealants out there, but these are only a couple that managed to impress us with their results. Hopefully, we helped you narrow down your search for the best sealant for your needs.

Our Recommendation

NameCategoryProduct
Gasgacinch 440-A Gasket Sealer and Belt DressingBest OverallGasgacinch 440-A Gasket Sealer and Belt Dressing
Permatex 81160 High-Temp Red RTV Silicone GasketBudget PickPermatex 81160 High-Temp Red RTV Silicone Gasket
Steel Seal Blown Head Gasket Fix Repair SealerUpgrade PickSteel Seal Blown Head Gasket Fix Repair Sealer