Sikaflex 221 bonds well to a wide variety of substrates and is suitable for making permanent, high adhesive strength elastic seals. Use 221 on substrate materials wood, metals, metal primers and paint coatings (2c or 2 part systems), ceramic materials and plastics.
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Sikaflex-221 is a high-quality multi purpose non-sagging 1-component polyurethane sealant that cures on exposure to atmospheric humidity to form a durable elastomer.
1-Component Formulation (1C)
Resistant to aging and weathering exposure
Can be painted over
Can be sanded
Bonds well to a wide variety of substrates
NSF-approved for incidental food contact and potable water.
Sealant type: Polyurethane
Temperature: -40 to 195 F
Time until tack free: 60 min
Full cure time: 60 min to 10 days
Tensile Strength: 260
Hardness: Shore A 40-45
Specific Gravity: 1.27
Number Of Parts:
Will this product stick to Hypalon to repair transom joints on an inflatable boat? Can it be applied over old contact cement residue and still adhere with a strong bond?
We used it on an aluminum horse trailer roof. It did adhere to the oldcement which was the same product only, many years old.
There is little reason not to think this will work for you. But without knowing the old glue and what it is, we would recommend testing in a small spot for proper adhesion.
JD Tech Associate
Can sicaflex 221 be used on frp
JD Tech Team
What is the adhesive strength? Is it like 5200 or 4200. IO want to use it on a hatch that at some future time may need to be disassembled.Thank you.
I don't know the answer you could Google it I'm sure
I'm sorry I cannot answer this question. I used the product to seal the joints of an aluminum horse trailer. It worked beautifully.
This is not the product to use if you will need to take it a part, unless it is really thick components that you could use a crowbar on, it would still de difficult.
Does this product work when it is applied underwater?
No, surface must be clean and dry.
using on blackwater vent pipe where it connects to tank will this work?
Depends on what you are using it for. If you are trying to repair a broken part it probably wont work for you as this stuff is pretty pliable when it cures. If you are sealing the threads then it may work, but there are cheaper alternatives. This is really good for sealing things like seams or moldings to prevent water intrusion. The adhesive properties of this stuff are great and it stands up to the sun really well. I have used it on plastic fiberglass, and aluminum and I have not found a sealer that works beter. Be advised though, only buy as much as you can use. The shelf life is not good and once it starts to set up it is useless.
It should work. The surfaces must be clean and dry. I have used it on a farm sprayer tank to fix a crack in the plastic. I used it on a metal stock tank to seal the bottom seam and it worked well. I worked a at factory which made aluminum delivery bodies (UPS) and they sealed all the bodies with it.
Not the way we used it. I'm not the right person to even ask. Sorry
WALTER A FURMAN CO
Most likely. As long as it is a low heat water system you should be fine, this stuff is pretty resilient.
how much tube we need of sikaflex 221 if we have 3meter x 2cm x 2cm surface? one tube is how much surface it will take?
One tube should cover your requirements plus some left over.
need to seal stainless steel seams in a swimming pool, in Michigan, is the product resistant to chemicals and cold?
Yes, should work great for that. We use it on waterslide seams and it's the best stuff we've found.
would you recommend this product for a swimming pool in Mi, most of the caulk would be underwater, I also need a gray or clear color to match
Yes, it should work for that application.
Chemical resistant to freshwater, sea water, limewater, sewage effluent, diluted acids and caustic solutions. Temporarily resistant to fuels, mineral oils, vegetable and animal fats and oils; not resistant to organic acids, alcohol, concentrated mineral acids and caustic solutions.
Does it work with Polycarbonates. I.E. Plexiglass?
Sorry I do not know. I used it on Formica countertop.
Best is to use Sikaflex 295 UV. not the 221.
i have used it under Lexan. It held up better then any other adhesive caulking that I have tried. I used it under Lexan custom made skylight on house in NY and MA. I have also used it on horse trailer roof vents - works very well. Other the Sikaflex , I have used Vulkem caulking very great success
have sikaflex-221 in black would like to know how long befor i can paint over it ?
Most of the common paints (except some alkyd-based paints, like some sold by Petit and Interlux) can be used on top of SikaflexÂ•Ã€_Â•Ã€__Â•Ã€_Â•Ã€__Â•Ã€_Â•Ã€__ products. Generally, the best results are obtained when the adhesive / sealant is fully cured. The exception to this is the SikaflexÂ•Ã€_Â•Ã€__Â•Ã€_Â•Ã€__Â•Ã€_Â•Ã€__ 500 series products where the paint should be applied before the sealant has formed a cured skin on its exterior surface. Whenever over-painting is desired, it is highly recommended that the paint compatibility with any Sika product be confirmed using appropriate and representative paint application parameters prior to use in the final application. It should also be noted that rigid paint systems prevent joint movement. This can lead to cracking of the paint applied overtop of any Sika product.
How many square metre can a tube of Sikaflex 221 fill up? I need to do caulking in between my timber floor 10m2 with 5mm gap.
I was disappointed in the sealant. It was expensive and it leaked when I used it on my hatch plexiglass. I had to reseal it. Gary
Purchased to repair Inflatable transom
Purchased this to repair my 9 ft. aluminum hull RIB. The transom was poorly glued from the manufacturer and separated from the tubes. I needed an adhesive that had not only good adhesive characteristics but the ability to stretch in the joint to handle the various pressures in an inflatable goes through during the many heating and cooling cycles in a day. Product was used on the tubes and the aluminum "cups" built into the transom. Careful cleaning, clamping and ample curing times seems to have yielded a strong bond. Don't try to rush the product. Follow directions.
Saucon Valley, PA
This stuff is awesome and Jamestown has the best price.....
This stuff is awesome. If you roughen up the surface it will bond to almost anything. The only thing it is not recommended for is Masonary and Concrete. There are better products like NP1 by BASF. This stuff can be messy but you would expect that and acetone or lacquer thinner takes it off no problem. Any solvent thinner will actually clean it up but acetone or lacquer thinner are the best for cleaning the surface before application because they don't leave any residue. Don't buy more than you need of the 221 but if you have an old tube that the end hardens up on, just poke a hole below the cured area and squeeze it out. Tape over the hole and work your way down the tube. Store in a dry place as this stuff is moisture cured. Needs a couple of days at least before painting over to be safe. Moisture and temperature will determine this. I warm the tube up before using it either in the sun or with a heat gun and it really helps with the flow and application. Heck I use some of this to put part of woodstove door gasket back in place and it is still there. Totally violating what this product is made for. If you had to have one tube of sealant around, this would be the one. Always have a tube in my shop. You will not be disappointed with this product.
Firewire300 aka VE3OPD
EN58 near Duluth MN
Used it to put a back window into a convertible.Good, but messy, goop.
Bill the Mechanic
This product really shines
We replaced a bulkhead that butted up against the side of the house. That edge had about a 1/4" crack that needed to be sealed. At first, we tried caulking the edge, but the caulk failed and leaked from the rain and the runoff from the roof. I searched around and found the Sikaflex product which is advertised as a marine sealant. So, I tried using the Sikaflex in place of the caulk. The product worked great. It can fill and seal a much larger crack than caulk can and it has proven to be totally waterproof. It also spreads uniformly and isn't unattractive.
I have bought Sikaflex again and again
This was for doing seam along gunwhale. Taped gunwhale and deck using 3M 2090 blue tape and then used a small teaspoon as tool, and gloved finger in tight areas. Used soapy water as tooling agent with great results. Did about 3 foot sections and moved steadily along. When satisfied, pulled up tape immediately. Used alcohol immediately to clean up any accidents. Looks great.
Sika above and below
Unlike 5200, hardware can be removed without damaging the points of adhesion. While it can be used underwater, it's best uses are for bedding pretty much anything on a boat. As it dries to a rubbery consistency you can even use it to mount pumps to flat dry surfaces, including bilge pumps and float switches. Excess can be left on to dry and then can be trimmed and peels off. It sands very well and can be color matched with your favorite paint.
West Hartford, CT
good stuff for elastic seals....
Wish I'd purchased the white version, but this stuff works well as a long term sealant on any application that involves movement. I used it on my RV, and it holds up well against the weather as well as against the motion of a Motorhome in transit.
sealed slideout in RV
Great product and great service
Great waterproofing product. Excellent sales experience.
I actually used this product to seal the sewed seams on my wetsuit. It worked great. Used the left overs on some wooden framed windows on a 37 Elko, still water tight.