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Flex Seal vs. Leak Seal | Which To Choose?

While there are pros and cons for flex seal and leak seal, Flex Seal is most often recommended for its maximum durability, flexibility, and color options. However, If you need something that dries fast and handles extreme temperatures well, choose Leak Seal instead. 

While both of these seals offer similar characteristics, let’s go over more specific details of each. 

Flex Seal

While both of these seals have many benefits, Flex Seal, in its current form, is known as the more reliable choice. Flex Seal gives you a more rubbery finish that is flexible and less likely to fall apart over time. For most projects, this rubbery finish will do a great job of holding everything securely, but it may not be best if you need hard layers of a seal. 

Pros: 

  • Thicker: The consistency of Flex Seal is key in allowing it to hold leaks better. The rubbery texture of the finish is thicker than Leak Seal, which allows it to hold stronger than Leak Seal while still being flexible if needed. 
  • Color Options: If you want to seal a crack but don’t want to have to brush it over, Flex Seal can help with that. You can choose from 12 different color options to help you hide the repair you made without the hassle of painting over it. 
  • More Secure Seal: The thickness and rubbery texture of Flex Seal allows it to have a stronger, better overall hold. The longer dry time is well worth the amount of strength that this seal provides. This is where Flex Seal truly outshines Leak Seal. 
  • Tight Spaces: One major benefit of Flex Seal is that it gets into tight spaces without much effort. With other products like sprays and caulks, you need to force the product into those spaces. Flex Seal does this for you instead. 

Cons: 

  • Longer Dry Time: Compared to Leak Seal, you can expect Flex Seal to take longer to dry. Part of the reason is that it is thicker. This adds more time that it needs to dry before it can be effective compared to the thinner competitor. It will take about 2-3 hours to be dry enough to handle, whereas Leak Seal only takes about one hour. 
  • Applying Additional Coats: Another major con to using Flex Seal is that you must wait about 24 hours to apply a second coating. Because Leak Seal is thinner, you can apply a new coat of that every 30 minutes. 
  • Not as Good in Extreme Temperatures: While Flex Seal can last a long time, you can run into some issues in extremely high or low temperatures. The rubbery texture can’t always withstand major temperature changes without cracking. 

Leak Seal

Leak Seal is a little less reliable than Flex Seal regarding long-lasting protection, but it still has many advantages. You can apply many more coats o leak seal over a short time compared to Flex Seal, and it does much better in extreme temperatures. 

Pros: 

  • Better in Extreme Temperatures: The main advantage of Leak Seal is its ability to withstand severe temperature changes without cracking over time. This is partially due to its makeup. Where Flex Seal dries with a rubbery consistency, Leak Seal is hard. This allows it to withstand temperatures better as it is a hard material without flexibility. 
  • Applying Additional Coats: You can apply a new coat of Leak Seal every 30 minutes until it reaches the consistency that you want. So you won’t need to wait an entire day to add more to your layer. This helps you save time and make the project a one-day achievement rather than waiting for another day to finish. 
  • Faster Dry Time: Leak Seal will be dry enough to handle about an hour after you apply it. If you want it to fully cure, you must give it about 24 hours. After that, Leak Seal is ready to go and will hold for a long time. 
  • You Can Paint Over: Unlike Flex Seal, you can paint over Leak Seal as it is not rubbery and it will not be difficult. Because it comes in fewer colors, you will need to paint it the color you want. Thankfully, with this formula, you can. 

Cons: 

  • Fewer Color Options: Leak Seal only offers four basic color options for you to choose from. This may be enough for some following more basic color schemes, but for others with different colors, you may need to paint over it. 
  • Not Flexible: Leak Seal, unlike Flex Seal, is not flexible. This allows it to be harder, but it can be detrimental when you need flexibility. So, remember that Leak Seal is hard, like a coating of paint, rather than rubbery like Flex Seal. 
  • Thinner: The quick reapplying and drying times are due to this seal being thin. There are some cases where this can be a benefit, but it also means you need multiple coats for it to be as strong as Flex Seal.

Related Is It Okay to Drill Into Vinyl Siding? (With an Alternative).

Flex Seal and Leak Seal Similarities

While we now know the main differences between these two sealants, let’s talk about their similarities. 

Pricing

Both options cost about the same, and neither will break the bank. They are both reasonably inexpensive, especially compared to repair costs for leaks. Both will cost you between $10 and $15, depending on where you buy them. So, you don’t have to worry about spending too much money on one brand or the other. 

Working on a Dirty, Rusty, or Wet Surface

Neither Flex Seal nor Leak Seal works well in unclean or wet conditions when first applying them. You must clean the area before applying to get the most out of both products. You need to dry the surface completely before applying both products when using either one for leaky pipes or other areas.

Both products stand up well to leaking water. However, they both need time to dry without coming in contact with water to dry and cure properly. So, ensure you completely dry and clean any area you want to use these products on before applying them for the best possible results. 

Application

While both options provide you with different benefits, they have very similar application rules. Both require you to hold the spray about 10-15 inches (25-38 centimeters) away from the surface for maximum coverage. They also both require a clean, dry, rust-free surface to allow curing. 

With both products, take your time and fill all gaps and cracks well before you finish. This will help it seal and remain tight. With Leak Seal, you don’t have to be quite as careful because you can apply another coat in about 30 minutes. If you are using Flex Seal, you must be more careful to fill in those cracks as you have to wait a full day for another coat. 

Limitations

These sealants have limitations regarding when, how, and where to apply them. You should never use either of these sealants on anything you will consume. They are not safe to use with drinking water or food containers. 

It is important to know that both of these products are non-toxic, but that doesn’t make them safe for consumption. So, be careful where you use them. 

You should also use these products in a ventilated area as both will give off a strong odor. This odor can be harmful in high doses. It is best to make sure that you are careful when applying this. Wear a mask if in an enclosed area and open windows when you can. 

Leak Seal vs. Flex Seal in Action: 

Now that we covered some of the basic pros and cons for each product, let’s talk about which product that is recommended for different jobs. 

If You Are Looking for:I Recommend:
Better priceBoth are about the same
Color optionsFlex Seal
Flexibility Flex Seal
Floor sealingLeak Seal (not slippery) 
Getting into tight spacesFlex Seal
Layering quick coatsLeak Seal 
Outdoor sealingLeak Seal (resistant to temperatures)
Surfaces that are already wetBoth work equally
Won’t crack or chip away Flex Seal

Here is a good video where both options, among others, are tested:

Can I Use Flex Seal on a Leaky Pipe?

You can use Flex Seal on a leaky pipe. It will adhere to the pipe and close the gap allowing the water to leak through. If you want the best possible results, ensure the pipe is dry before applying, as Flex Seal and similar products do not work as well on wet surfaces before they are completely dry. 

What Is the Best Sealant for Leaking Pipes?

While Flex Seal and Leak Seal both work well against leaks, I recommend Flex Seal as the best sealant for leaking pipes. This is because Flex Seal gets into tight spaces better, allowing for a complete hold and maximum leak protection. 

Final Thoughts

Overall, I prefer Flex Seal over Leak Seal, but both have their own pros and cons. Remember, you need to apply both products to a clean, dry area for them to work best. Also, don’t use them in any space containing food or drinking water, as it can harm you. 

Both options provide a good hold for leaks and other household issues. So, choose whichever option seems to fit your needs the best.

For more, check out Can Duct Tape Be Used Instead of Electrical Tape?

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