Sikaflex 291 Vs. 3m 5200 Vs. Sikaflex 292i: What’s the Difference?

I did try using some regular polyurethane sealant from the hardware store and Sikaflex 291 is so far and beyond a better product. When it’s wet it’s easier to work with, and when it dries, it doesn’t shrink and it’s far more durable. I absolutely recommend it.

Sikaflex 291 Vs. 3m 5200 Vs. Sikaflex 292i

Sikaflex 291 Vs. 3m 5200 Vs. Sikaflex 292i: Specs & Uses

The main difference between Sikaflex 291 Vs. 3m 5200 Vs. Sikaflex 292i is:

Sikaflex 292iSikaflex 2913M 5200
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Datasheet๐Ÿ“ฅSikaflex 292i๐Ÿ“ฅSikaflex 291๐Ÿ“ฅ3M 5200
Chemical Base1-component polyurethane1-component polyurethaneTough/flexible polyurethane polymer
Color OptionsWhiteWhite, BlackWhite, Black, Mahogany
Cure MechanismMoisture-curingMoisture-curingOne component, moisture curing
Density1.3 kg/l1.3 kg/l11.3 lb/gal
ConsistencyThixotropic pasteNon-sag pasteCaulkable, non-sag paste
Skin Time40 min60 min4 hr
Open Time30 min45 min
Curing SpeedFaster at higher temp/humiditySlower at lower temp/humidity1-8 in per 5 days
HardnessShore A 40Shore A 40Shore A 68
Tensile Strength3 MPa1.8 MPa4.8 MPa
Elongation at Break400%500%700%
Service Temperature Range-50 to 90ยฐC-50 to 90ยฐC-40 to 90ยฐC
Shelf Life12 months12 months24 months
UsesSeal gaps between the roof and the camper body: can be applied to seal the gaps between the roof and the camper body. It provides excellent adhesion and creates a strong bond. However, it is not recommended for extended outdoor exposure due to its lack of UV stability. For outdoor applications, a UV-resistant sealant like Sika 295UV is recommended.


Installing RV windows in a sprinter van: not recommended for installing and repositioning RV windows. This adhesive is too permanent and may not allow for easy removal or repositioning of the windows.

Replacement of leaking port windows: If you are experiencing leaks in your port windows and have previously used 3M 5200 sealant, Sikaflex 292i can provide better adhesion for a permanent bond. However, it’s important to note that removing the existing window sealed with 5200 may require destructive measures, as 5200 fully cures and becomes difficult to remove. Using a heat gun in combination with a putty knife can help carefully break the 5200 seals for window removal.
Sealing around rivets on bare aluminum: ideal for sealing rivets on bare aluminum surfaces, making it suitable for applications like sealing rivets on a Sprinter van or other aluminum structures.

Attaching a spoiler: Sikaflex 291 is well-suited for attaching a spoiler to a vehicle or any other suitable surface. Its adhesive properties ensure a reliable and long-lasting bond.

Sealing weld points on a roof basket with powder coat: Sikaflex 291 is effective for sealing weld points on a roof basket with powder coat. However, for better UV resistance, Sikaflex 295UV or Sikaflex 521UV is recommended for outdoor applications.

Bonding pool tiles: strong adhesion and durability make it an excellent choice for this specific application.
Securing Galvanized Sheet Metal to an Aluminum Boat: Use 3M 5200 to bond galvanized sheet metal to an aluminum boat, ensuring both surfaces are clean and free of patina.

Repairing a Submerged PVC Pipe Coupling: When dealing with a 2-inch PVC pipe coupling that is underwater and cannot be moved or drained, 3M 5200 is an excellent choice for repair.

Bonding Polyethylene in Kayaks: 3M 5200 is suitable for bonding polyethylene in kayaks, creating a permanent bond that cannot be removed once fully cured.

Read More: vulkem 45 ssl vs sikaflex

๐Ÿ“ My Hands-on Test of Sikaflex 292i

Sikaflex 292i Product
I used this Sikaflex 292i to attach a side flare to my camper conversion and seal around it. So far it has done a great job holding everything in place.

My only complaint is how hard the tube is to squeeze without a caulk gun.

Once applied, it was easy enough to tidy up the excess. I have purchased it again for other projects on my van and will likely buy more in the future if needed.

Sikaflex 292i for marine uses
Overall, for my application, Sikaflex 292i has worked well. The adhesion was immediate and the cure time was fairly quick. A little bit of product goes a long way due to its thick consistency.

While a softer silicone may spread more easily, with the proper tool the paste-like consistency of this PU sealant was manageable.

The main downside I’ve noticed is that once opened, the tube dries out over time making it difficult to use the entire contents. However, the seal I applied under my RV remains intact even after long periods submerged in water.

I also used it to glue our shower pan in our motorhome and it works great, barely even noticing it’s there. The name alone is a guarantee. I used it to glue an stainless steel engine mount with bolts and nuts. The result was perfect.

Sikaflex 292i Product

๐Ÿ’ฌ FAQ of Sikaflex 292i

Q: Will this work on keelguard on the bass boat that will be underwater?

A: While Sikaflex products are suitable for bonding to hull surfaces, I cannot be certain this specific adhesive is compatible with underwater applications without reviewing Sika’s technical data and application guides for marine usage.

Q: Do you guys think this is better than 3m 5200? Every time the temperature changes I get at least one leak from my port windows and it is always the 5200

A: 5200 sealant is not suitable as a structural adhesive or bedding compound for windows due to its elasticity and weathering characteristics. Here is my test of it: 3M 4200 Vs. 5200. Sikaflex 292i would provide better adhesion for a permanent bond. However, removing your existing window will likely require destructive measures since 5200 has fully cured. I suggest using a heat gun in combination with a putty knife to carefully break the 5200 seals for window removal.

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2 reviews

    • You could apply it to seal gaps between the roof and the camper body. However, since this is a very strong adhesive, removal may be difficult in the future if needed. This product has excellent adhesion but lacks UV stability for extended outdoor exposure. I recommend a UV-resistant sealant like Sika 295UV for outdoor applications.

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๐Ÿ“ My Hands-on Test of Sikaflex 291

Sikaflex (Sikaflex-291)
Sikaflex 291 is the absolute go-to for any type of sealant needed on oceangoing yachts. I’m back in the States now and working on a camper conversion project and I’ve mainly been using Sikaflex 291.

The material in the dispenser is great, I’ve used it in a standard caulking gun for years and never had an issue. But when trying to dispense the caulk from the smaller tube, I struggled for a while to apply a simple 3ft bead.

Therefore, while the caulk/sealant itself seems to be a good product overall, the tube and applicator can make dispensing it very difficult.

holding Sikaflex 291 in my home
In terms of its application, Sikaflex 291 is particularly useful when installing roof-mounted solar panels with 3M tape. It provides a self-leveling solution and is available in both white and black. Unless you’re specifically installing Zamp Solar Obsidian panels, I would recommend using the white sealant.

I also used it to reinforce the weak boat deck. I drilled holes and injected the sealant, adding weight until it dried. During the process, I could actually feel it heating up as a reaction. It’s worth noting that while it worked great, you should be aware of this heating reaction. Additionally, I used it along with some screws to attach the starboard, and it held up well.

When I had to redo the sealant around my boat’s rub rail, I found that Sikaflex 291 worked much better than the product I had previously used.

The finish achieved with Sikaflex 291 sealant is smooth and far superior to silicone. However, it’s important to wear gloves when using them because it tends to stick to your fingers.

Sikaflex (Sikaflex-291)

๐Ÿ’ฌ FAQ of Sikaflex 291

Q: Can Sikaflex 291 be used to seal around rivets on bare aluminum?

A: Yes, this product can bond to bare aluminum and it worked well for sealing around the rivets on my Sprinter van. I am very satisfied with its performance, as it has not shown any wear even after a year. I would also recommend the 3m 4200 Marine Adhesive.

Q: Will Sikaflex 291 adhere to rubber?

A: I am not sure about its bonding ability to rubber, but I can confirm that it can stick to other materials such as stainless steel, fiberglass, teak, and cork, as well as clothing and leather.

Q: Is Sikaflex 291 suitable for attaching a spoiler?

A: This product would likely work great for attaching a spoiler.

Q: Can it adhere to a powder coat, such as for sealing weld points on a roof basket?

A: Yes, Sikaflex 291 would be appropriate for this application. However, if the substrate will be exposed to outdoor elements and sunlight, it is recommended to use Sikaflex 295UV or Sikaflex 521UV instead.

Q: Is it safe to use on acrylic?

A: Sikaflex 291 is not recommended for bonding acrylics due to the potential for stress cracking. For this purpose, Sikaflex 295 is the appropriate product.

Q: What is the UV resistance of this product?

A: Sikaflex 291 does not have UV resistance, so over time it may degrade and become chalky if exposed to UV. However, it is paintable and can be coated with a UV-resistant layer to prevent degradation.

Q: Can it bond to High-Density Polyethylene?

A: Unfortunately, Sikaflex 291 and other sealants would not bond to High-Density Polyethylene due to its low surface energy.

Q: Can it be used on plastic and PVC?

A: Yes, Sikaflex 291 can be used on plastic and PVC.

Q: Can it be used as caulking for tile?

A: While it was not purchased for this purpose, Sikaflex 291 is a sticky and flexible product that works well as an adhesive and may be suitable as a caulk for tiles. The tube label indicates that it is a soft and flexible product after drying.

Q: Will an opened tube remain usable for several days or will it quickly harden in the tube after opening?

A: If the tip is sealed well, an opened tube of Sikaflex 291 can remain usable for at least a week or two.

Q: Is it truly self-leveling?

A: It is somewhat self-leveling, but it is not recommended to use too much in one spot.

Q: Is it suitable for gluing a foam butt pad to gelcoat on a kayak?

A: While I am not sure about this specific application, Sikaflex 291 has shown good adhesion underwater once it has dried. It has been used successfully to bond pool tiles.

Q: Is it resistant to mold and mildew?

A: Polyurethane products, including Sikaflex 291, are typically not resistant to mold or mildew.

Q: Can it bond to Sika715 self-leveling RV roof sealant? What is the minimum temperature required for application, and how long should it dry before getting wet?

A: The minimum application temperature for Sikaflex 291 is 41ยฐF, and it is recommended to keep the tube indoors until use. The cure time varies based on temperature, but it should be tack-free within an hour. Ideally, it should be given a few days to dry before exposure to water. For compatibility with Sika 715, it is best to contact Sikaflex. Generally, it is important to avoid using silicone-based products with Sikaflex, as only another silicone-based product can bond to silicone after it has been properly cleaned.

Q: How long does it need to dry before being subjected to freezing temperatures and rain?

A: Sikaflex 291 should be allowed to dry for 24 hours above freezing and free of rain before exposure to freezing temperatures and rain.

Q: Does the tube come with a cap for resealing?

A: No, the tube of Sikaflex 291 does not come with a cap for resealing. However, a cap from another tube can be used.

๐Ÿ“ My Hands-on Test of 3M 5200

3M 5200
I’ve been using the 3M Fast Cure 5200 for years, primarily on my boat. Whenever I drill a hole or put a screw into the boat’s hull or transom, this stuff is going on the screw threads or in the hole to seal it from water permanently. It’s pretty amazing stuff. I’ve even patched holes up to 1/2 inch in diameter using just 3M 5200, and I’ve never had a drop of water get in through that hole afterward. It’s a must-have for boats, keeping them afloat without any leaks whatsoever.

The only downside to the 3M Fast Cure 5200 is that it can be messy and not very reusable. Even the small tubes are expensive. However, if you cap it after using it, make sure you find a way to use the rest of the sealant in the not-too-distant future, as the cap will become difficult to remove, and the sealant will harden up near the cap. Despite that, 3M 5200 sticks to just about every type of material on the planet and is impenetrable to water.

3m 5200 works as a permanent seal for my boat drain plug housing
I’ve used this stuff on my Smyth Ute car conversion, specifically to glue the plastic taillights to fiberglass. It worked wonderfully. The taillights are securely in place, and if I need to replace a bulb, I can carefully remove them by flexing them a bit and then reapply the product to resecure them. This adhesive is truly reliable.

Moreover, I’ve also used 3M Fast Cure 5200 to glue in my plexiglass rear window on the car conversion. It provided a strong bond, and I’m on my second tube now. If anything, it’s almost too good!

In my experience, I use 5200 for everything that needs a permanent bond. This stuff is truly amazing and well worth the price. Just make sure to clean the surface thoroughly before application and allow it to cure for a couple of days. Once it’s cured, you won’t have to worry about it coming free. I’ve used it on boats, and vehicles, and even repaired cracks in my shoes. I can’t say enough good things about it.

Another great aspect of this sealant is its flexibility. I recently used it to repair and seal cracks on my muck-style snake-proof boots, which I wear daily for work in swamps. It worked perfectly, remaining flexible and providing excellent adhesion. It’s a versatile adhesive that goes beyond just marine applications.

While the 3M Fast Cure 5200 is a fantastic product, it’s important to note that it’s permanent in most cases. So, if you’re looking for a more practical and easier-to-use option, consider using ‘4200’. It can be just as effective and offers more flexibility for certain applications.

3M 5200

๐Ÿ’ฌ FAQ of 3M 5200

Q: Can I use 3M 5200 to secure galvanized sheet metal to an aluminum boat?

A: The effectiveness depends on the load. If you remove the patina from both surfaces and ensure there is enough bonding area, it should work. Make sure to secure the joint until the adhesive is fully cured.

Q: Is this adhesive suitable for repairing a 2-inch PVC pipe coupling underwater?

A: If the coupling is submerged and cannot be moved or drained, this would be your best option for repair. Clean and steel wool the surface before applying the adhesive. While I can’t be certain if this will solve your specific situation, I have been impressed with 3M 05220. It was specifically designed to stick to the fiberglass hulls of boats while they are still in the water.

Q: Does this adhesive work on polyethylene used in kayaks?

A: Yes, once it sets, it cannot be removed.

Q: Can 3M 5200 be sanded?

A: Once fully cured, it can be sanded. Keep in mind it may clog the sandpaper slightly. The quality of surface preparation determines how well the adhesive sticks and how finely you can feather the product.

Q: Will 3M 5200 effectively glue a clear vinyl window to the soft top of a 1997 Mazda Miata?

A: It is possible, but I would recommend consulting a professional installer. Keep in mind that using this adhesive may limit future options.

Q: Can I use this tube with a typical caulk gun used for regular window caulk?

A: I had the same concern, but the tube has an internal plastic plunger cup that a traditional caulking gun presses against. It is similar to a traditional caulk tube. The additional metal seal helps prolong the storage of the adhesive sealant until you are ready to use it. However, once the seal is broken, there may not be much shelf life left.

Q: Will this adhesive bond metal to a porcelain shower tile?

A: Goop Glue would be better for that use.

Q: Would you recommend 3M 5200 for gluing a rubber pad to a fiberglass paddle board used in saltwater?

A: Yes, I recommend roughing up the fiberglass with at least 120-grit sandpaper and cleaning it thoroughly with acetone to ensure a clean surface. Apply the adhesive to both the fiberglass and the foam, then use a thick piece of plywood over the foam and clamp it down to provide even pressure during the curing process. Be aware that once cured, it will be extremely difficult to remove the foam. This adhesive is permanent.

Q: Can this adhesive be applied underwater, similar to the regular-cure 5200?

A: Yes, I used it underwater, and it has held up well.

Q: Can 3M 5200 be used to fill a 1/4-inch hole below the water line?

A: For plugging a 1/4-inch hole, I suggest using a 1/4-inch machine screw in bronze or stainless steel. Coat both the screw and the hole with the 5200 adhesive, then secure the nut on the screw. While it can be used as a sealant, it is best to plug the hole with the screw. Once cured, it will be nearly impossible to remove the nut or the screw from the hole. I have used it underwater to install fittings on scuba equipment below the waterline, and it works effectively.

Q: Will this adhesive work on lightweight fabric?

A: I assume so since this adhesive sticks to anything. Think of it as silicone.

Q: Can this adhesive fix a leak in a hypalon inflatable?

A: No, it will not. It is specifically designed for bonding with fiberglass.

Q: Can 3M 5200 be used instead of grout for an in-ground pool?

A: They make sanded and unsanded caulk in colors that match grout, which would be a better option for your pool.

Q: Will 5200 fast cure adhere to gelcoat with a wax additive?

A: While 5200 sticks to most surfaces, I always sand the surface to provide better adhesion. I would not recommend applying it directly on top of a wax additive.

Q: Is this adhesive removable?

A: Removing it would be challenging; it is highly adhesive. If you want the option of removal in the future, consider using a different product. 5200 is meant for permanent applications, while providing a strong bond, it may not be the best choice if you anticipate needing to remove the adhesive later.