- Aluminum Foil Tape 3340, 2.5" x 50 yd, 4.0 mil, Silver, HVAC, Sealing and Patching Hot and Cold Air Ducts, Fiberglass Duct Board, Insulation, Metal Repair

Genuine 3M product, Quality as expected, Easy to cut to the correct size before placing it, with the backer paper protecting the sticky side, but sticks were you put it. I used this to patch some gaps in aluminum ductwork directly below the furnace output, and it has stayed stuck through both Heating and Cooling cycles.

This is the good one, this stuff is tough too. I always like to have some on hand for projects around the house. You’d be surprised how useful this tape can be once you have some on hand. My dad always used this at work (HVAC) so I’ve learned over the years how to properly use this tape to make my A/C more efficient. This is great for taping up cracks around your furnace or condenser coil. You can also use it to tape the chill line near the outside unit if your lines have areas that are exposed, or if there are places that are beginning to be exposed. You can buy cheaper brands, but there’s some things you shouldn’t buy off brand, and this one of them. Buy the legit 3M tape, it’s worth it. It’ll save you money in the long run as you won’t constantly be having to patch up previous applications. I’m not a certified HVAC tech, but after riding with my dad from elementary school until I graduated, I do know to highly recommend this specific tape. This can also be used on small windows, such as the small window panes on some front/back doors, and for lots of other applications. If you’re a homeowner, I truly believe a roll of this tape should be in your home tool box.

Great stuff. Sticks very well

I would have given this product 5 stars except for the fact that no disclaimer or warning was given about the tape when it gets heated. The Acrylic adhesive has to cure. When I used it on my oil furnace venting pipe, it really stunk up my whole basement & the strong odor came upstairs. It was so strong of a chemical smell, I had to get up and remove the tape at 2:00 in the A.M. . The odor got better after the pipe cooled down, but we could still smell a faint odor for several days after in the basement, but not in our living areas. Bottom line is this, the tape does what it's supposed to do, but you need to really ventilate the area (for a day or two at least) if the tape gets heated. Use fans, open windows etc. I have not used it on any cold piping, but the acrylic adhesive gives the tape a strong smell even when cool.

Works and sticks good sealing duct frame for filters. USN came out with duct tape, submarines would use it to stick problem people to ceilings (no joke)

Good tape, used for taping seams between foam boards. Better than when you can get at hardware stores

Worked great on new duct work. Highly recommend

I tried a cheaper tape wich still wasn't that cheap. Had to learn the hard way 3M is thicker and has more adhesive then the generic brands cant go wrong with 3M Foil Tape. Not gunna show my work though even though it worked. Lol