304099 Foil-Grip 1402 Mastic Duct Sealant 2" x 100'

Great price for how much you get. Very sticky. Easy to use. I use on my hvac registers after cleaning them up. Keeps attic air out. Seems like quality product. Very strong. Does its job by making an airtight seal.

So, I like using heavy mastic and a brush. I have quite a bit of ductwork in the attic to strip and mastic. The problem being, after brushing on mastic, I can't run the AC until it dries, basically by the next day. Well it was 100° here the other day. It hit 140° in my attic: measured, not estimated. Welcome to spring where I live. Basically that's 2 days of not running the AC to mastic ducts. Rough. Then it occurred to me. I had already ordered this mastic tape but hadn't been using it. I can mastic tape the seams, then go downstairs and run the AC. This has been life cha... ok, maybe not. But it has given me options I hadn't realized I had before. I don't have to check the weather reports and pray for a string of cool days in order to seal my ducts and not fry for 2 days for each section I do. The tape sticks very well. If it didn't, no one would buy it. Free the edge of the backing from the tape, measure out the tape against where you want to put it, and notch the edge with a razor blade. Peel the tape from the backing past the notch, then cut the tape where the notch is. Don't cut the backing! Eventually you'll end up with a long strip of backing. Trim it off, but Not even with the end of the tape. You always want some backing there past the end of the tape. The other way lies madness. You do not want to be in the dark attic, sweating, cursing, trying to get a corner of the tape started off the backing. I expect I'll need more of this tape. I'll still use buckets of mastic where necessary like on register boxes where I can't always reach where I need to get with tape, but this mastic tape has made it more convenient for me.

This is the stuff, if you're looking for mastic tape then you have found it. This is the best mastic tape I have ever tried, I bought two rolls of this stuff and I've used almost all of it. I put down the gallon of mastic putty that we got and used this instead. If it doesn't want to stick when it's cold heat it up with a little bit of heat gun on the material that you're putting it on and stick it on there and I guarantee you it will not come back off. If you like to have it smooth and roll out all the little bubbles get one of them little rollers they use to put on I don't know if it's like screens or something but whatever there's a little flat 2-in by 1-in roller hard plastic use that to roll it on. I seen other people using like a bondo putty whatever spreader and we tried that it didn't work as well.

I recently went through my house and sealed the lip around all three of my bathroom fans and my one laundry room fan. I also went through my entire house and pulled up the air registers on my heating and air system and sealed all the ducts in the floor. This has made a dramatic difference in how well my A/C system is now working. I was getting a lot of cooling loss with my cooled air coming up and hitting my air registers and then bouncing back down the edges around my air ducts. I didn't realize how much air I was losing until I had them all sealed and felt how much stronger the air flow was up through the air registers. It was a night and day difference. My house was constructed in 1990 and you would think it would be fairly well constructed but some of the gaps around the ducting were 1/2" wide and all those gaps add up especially in a 2,600 sq. ft. house. I had previously done this same job with another type of HVAC tape but it didn't hold up to all the hot/cold cycles that this tape will handle. If you are trying to seal your ducts this is the tape you want. I have read other review about this tape cutting you and I didn't get cut once. I also read that this tape was hard to tear and it isn't. If you nick the edge of the tape with either a razor knife or just a quick tear with your hands this tape tears quite easily.

May not be the cheapest but this is some sticky tape and seals well.

The real deal. Not the junk that is sold by the big box stores.

Great mastic sealant tape. Nice thickness, very sticky and I have used 5 rolls recently and none have had damaged edges like I have read elsewhere. Just make sure the surface you are applying it to is clean, as I have found on a couple of less ‘clean’ surfaces the tape has pulled away some in unconditioned spaces after a couple of months of differing seasonal temperatures......otherwise very pleased with the product.

Very sticky and did the job.

Seals ductwork well, you will never get the ductwork apart. Thick glue with a good seal. Top notch.

There's no better tape period, this is the real deal. Quality product, pricy, but worth every penny. I had multiple air bleed connecting seams, did my entire basement ductwork with 100 feet and some left over to do a few more seams. Get some little scissors to cut it with, makes life easier. The utility blade crumples the corners a bit, which makes it trickier to get the backing off. Hope this helps!

This stuff is great! Seems good, flexible to get around uneven surfaces and mold to it/hold tight. Way better than the crappy little foil tape you get and the big box store.

This tape is absolutely amazing!.. a little pricey but worth the price!.. very strong and easy to apply!.