Sika Sikaflex-221, White, multi-purpose sealant/adhesive, polyurethane fast curing sealant, 10.1 fl. oz Cartridge

I have used this in all applications of wood construction.Just be aware...the two surfaces you put together with this are bonded into eternity.....be sure you really want that cause it is never coming apart again.I have to put a shelf into a fiberglass head liner. Obviously, I could not drive screws. I bonded 2x3 boards directly to the fiberglass. Then screwed to shelf into those boards. The shelf hangs from those boards. That was 4 years ago....nothing has moved at all. This is in my RV, bouncing up and down on some rough roads with the shelf fully loaded.....it is still as solid as the day I put it up

Initial impressions are that this is going to hold up better than silicone. Time will tell. I like the fact that it will cure even at very low temperatures, though it does cure more slowly. For storage of the unused amount, wrap the tip of the cartridge with cellophane and store the cartridge in the fridge. Keeps for months without hardening!Note: this urethane clings to your skin like nothing else -- it wipes off easy and doesn't feel sticky, but your fingers will be black for a week. Guaranteed. Nothing scrubs it off except time.

I made the decision to replace the bedroom vent with a Fantastic-fan. While up there, I noticed how horrible all of 2003/original caulk was. I purchased this SIKA for the rain/water channel running each side of the camper. I bought Dicor 501 for around the Fans, TV and Radio antennas. (not an expert just a regular Joe), The first tube had some damage so it was returned and quickly replacement (thank you Amazon). The next tube was perfect and ready for use. I will say, this is a little harder to use than the Dicor but I also believe they are two different products for two different uses. You better have strong forearms and grip b/c this stuff comes out slower and stiffer :) as a result it will stay where you put it and wont self level. Clean up wasn't that bad but my clothing might be another story. (Would I buy it again....absolutely)

Tried to plug it and reuse. It ate my 8" plug and refused a 2nd use. I pulled he plug out and my plug was a perfect preserved stick inside a coating of hardened adhesive. . A series of tiny tubes would work well use and discard a project at a time. Got one entire boat to work on? Do all the tasks at once.I am keeping it and will cut the cardboard tube to try to get more to scrape up. In future I would only open the tube when I had a HUGE number of things to glue or protect from water etc. all at once.

1 star because when using sealants the user often does not realized till its too late. In this case it was impossible to extract and I had to delay my project. I took a look and sure enough expired almost a year to the day. In other cases it might have caused a failure down the road making matters much worse, causing de-bonding of materials or water intrusion. Make sure the sealants and adhesives you sell are up to date!.Update: return request prompted seller to send out a fresh tube. Which expires in a month. Thanks a lot. If I could give another 1 star I would. Don’t sell old crap on Amazon.

I use this chaulk on commercial trailers and it works better than you can imagine! My commercial food trucks are exposed to constant harsh conditions. This stuff has great adhesion to both bare metal surfaces and painted metal surfaces. Seals better than anything you can buy at you local big box store. Can be painted and doesn't crack or shrink in any way! I think next time I install windows I'm gonna use this superior sealant.

As described and holding up well so far. Easy to apply. Tight bond and sealed perfectly. Will update if any issues .. but I doubt it.

Used to reconnect the neoprene matt to a blown plastic stand up up paddleboard. The Sola flex held the edges as well as the field. Performed better than expected.

Bought this product in white, went out to my trailer to use it in the roof and when I put it in the gun it came out black.Amazon replaced the first one and I bought 2 more. Just arrived today and still they are labeled white only they have black caulking inside.Kinda screwed now as I needed them right away to seal the roof before it rains.NOT HAPPY WITY THIS ISSUE

This stuff is amazing , I used it to seal my headlight , so flexible but dries really nice and stays flexible , also used it on my car window , no more leak , attaches very well to glass and metal and plastic , now im going to use it on my roof its awesome. Also got here really fast and we are about to get so much rain thanks amazon .

This Sikaflex 221 is amazing!!UL listed for potable water (black, gray, and white).I used a tube that was expired 1 year ago. After talking to an RV mechanic, if it flows good. If its solid, don't use it. Mine was still in very good condition. It is like a tar texture and worked great. Wear gloves, as it is really stick and won't come off your skin for days.

Came very quick. Great product drys fast. Though it can be a bit messy like any caulking/adhesive product. I accidentally leaned in a bit of it that had been on the grass. It's been 7 days and my arm is still covered in it. So seems to be pretty durable and long lasting.

Installed solar panels on roof of travel trailer. Didnt want to drill holes for brackets, so i researched and people used this stuff. I put on the brackets and tried to reposition one after it dried and i couldn’t budge it…so i am sure it will hold the panels on…