3M 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)

For any kind of tape, you can trust that 3M & Scotch will be the best. But be careful -- the edge of this tape is razor sharp and will draw blood if you're not.

Worked great on new duct work. Highly recommend

Good as expected

Ninguna otra cinta había podido funcionar con el tubo del aire acodicinado; colocamos esta y ya lleva algunos días sin que se caiga.

Selling fake Product in the name of 3M Returned and again received same product.

This foil tape is easier to work with them most of the other stuff. Great product would highly recommend it.

This is thick foil tape with a high temperature acrylic adhesive designed for sealing attic bathroom exhaust hoses etc with prominent code compliance labeling. It has a much stronger smell than other foil tapes I have used--definitely more of a pro class product and 0.5” wider than common foil tapes as well. Due to its thickness, it is also less conformable than what is ideal for average furnace and duct seam sealing purposes. I prefer thinner general purpose foil tapes in that role (Climaloc, Nashua 322, 3M 3311 etc). This does provide an added layer of protection for applying to sharp irregular surfaces as it does not tear easily, but it is also thick enough for its edges to cut you if you aren't careful.

I use this on clean, oil free duct work. Yes this is an expensive foil tape (cheaper if you buy it by the case) but the cold weather tack is effective and the adhesion will last for years even with the temperature cycles. I prefer the the thicker tapes (this is one of them) and 3M uses a quality adhesive. Tack is when the tape is first applied (TO A CLEAN SURFACE) and adheres to the surface. Adhesion is the ability to remain attached to the surface for a length of time and through temperature cycles. Flagging is the tape releasing from the surface (Adhesion has failed) and with the cheap tapes this happens in a few years. This is a pressure sensitive tape and MUST be smoothed down with an applicator and NOT just your hand. I believe in doing a job once and to the best of my ability and this tape has met my expectations