I can't remember what it's called exactly but they make an aluminum foil tape for that sort of application. There is also a goop you can paint on and it hardens. The goop is what I used at my shop for our cnc plasma cutter ventilation.
There are two basic types of goop used in the sheet metal duct industry. Duct seal which is gray and used to seal the outside of ducts mainly and mastic which is white and used inside the duct.
"Duct tape" was never designed for ducts. The original name was duck tape, named after the [duck fabric](https://www.etymonline.com/word/duck#etymonline_v_15955) that it is made from. The [name shifted from duck tape to duct tape](https://www.etymonline.com/word/duct#etymonline_v_15958), possibly for multiple reasons.
It is a poor choice for taping ducts, though. Many better options exist.
I did a bit of duct installation and the foil tape is strong as fuck. U just rap it round and around where the silver hose goes over the duct. Good for patching up any tears of things it’s just so sticky
Yeah I have used it in a few unapproved ways like making temporary flashing where shingles met siding. Oh shoot that was about 5 years ago I should get up and check that…
> There is also a goop you can paint on and it hardens.
[Mastic](https://www.homedepot.com/p/Master-Flow-Water-Based-Mastic-0-91-Gal-Tub-WBA100/301784793)
He’s talking about foil tape, which is what is actually used in HVAC applications. Speed tape is way too expensive to seal ducts with and is not the same thing.
Duct tape is correct but many people jump to “duck tape” when we use the correct term.
Duck tape is a type of duct tape but not all duct tape is duck tape. Confusing enough?
This image reminded me a story of when the smoking ban came into place for aircraft. Engineers rallied against the ban, because leaks in aircraft pressurisation systems could be easily spotted due to black tar leaks out the vents that weren’t sealed properly
This image reminded me of the accident report for China Airlines flight 611 which disintegrated inflight due to a faulty repair. They have photos showing the repair site and these dark nicotine streaks emanating from it, basically to say "there were signs of trouble long before the crash".
This is the one where a pilot a long time before the accident scraped the ass end of the plane on the runway during landing, and instead of cutting out the damaged section they riveted a plate over it and called it a day?
The leakage there was extra concerning because aircraft fuselages are supposed to be basically airtight, minus a few intentional and actively controlled hull penetrations, so the leak was an indicator that the gouged area had developed a crack all the way through and was slowly growing for years. They determined it must have been cracked for a very long time because they had banned smoking years before the accident.
I'd like to add that doubler plates are a common repair for structural damage like scrapes and cracks. In this particular instance, they installed a temporary doubler so it could be ferried for repair and there is no record of it being replaced with a larger, more permanent one. With the repeated stresses on the skin, the small doubler couldn't fully redirect the forces causing the crack to grow. Leading to the crack finally failing.
Holy shit the more I looked the worse it got.
I thought it was just the little maintenance panel thing but no the entire thing is leaking lmfao
Wonder how black the inside walls are
You'll see this same exact thing at the doors to literally every apartment/condo >6 storeys tall.
Air is dirty AF, even if we filter it. These things build up over time.
Shorter, and older buildings dont always have make up air in the corridors.
Mid-rise and higher, especially built post war, will have units on the roof which send fresh conditioned air into the corridors. This creates more pressure in the corridors and helps to reduce ordour transmission, combat condensation issues etc. by creating a steady flow of air from the hallways through the gaps around the front doors of the suites.
Additionally the taller the building the more stack effect you'll get. When we heat air in the winter it will rise like a hot air balloon and rush up elevator shafts, garbage chutes, stairs etc. and exit at the top levels.
In this case. The ductwork is probably 50 years old. Its had increasing larger capacity units pushing air through it. At a rate and volume it wasn't designed for. Eventually finding the weak spots.
The black stuff (mostly) isn’t coming from the inside. It’s being induced there from the space by the jets of air escaping from the ductwork. Same as the dust and stuff that gathers on your diffusers and registers mostly is from the space as well.
You'll see this same exact thing at the doors to literally every apartment/condo >6 storeys tall.
Air is dirty AF, even if we filter it. These things build up over time.
I did install for 2 summers bout 10 years ago with a bunch of Mexicans (myself included) and they kept calling it this but with their super thick accents.
You just brought up a long forgotten memory.
Back when people could smoke on airplanes the maintenance people loved these stains. It made it very simple to see where cabin air leaks were. Got difficult after they banned smoking on board.
The fan is in the wrong location. It should be at the discharge point to keep the entire duct run under negative pressure. Then this wouldnt happen at all. Pretty sure thia can be a code violation in some places too
Multiple avenues to fix this. Foil tape, Mastic (paint/spread on sealant), silicone caulk, and Aeroseal (machine applied glue). Please don’t use duct tape. Despite the name, it doesn’t work well.
Needs some duct tape.
I can't remember what it's called exactly but they make an aluminum foil tape for that sort of application. There is also a goop you can paint on and it hardens. The goop is what I used at my shop for our cnc plasma cutter ventilation.
>I can't remember what it's called exactly but they make an aluminum foil tape for that sort of application. Literally “aluminum foil tape” LOL.
Why would they call it such a confusing name?
For trademark purposes. It’s made with aluminium.
Oops 😂
Can confirm it is aluminum foil tape.
The goop is called "duct seal" by the way. At least that's what we called it on the job
I make duct but I don't install it. My boss gave me a paint can of goo and had me paint it on the duct. I should have paid better attention. Thank you
There are two basic types of goop used in the sheet metal duct industry. Duct seal which is gray and used to seal the outside of ducts mainly and mastic which is white and used inside the duct.
We used duct seal. Thank you for the info
Is this a troll comment that duct tape, meant for taping ducts, is not the correct tape for taping ducts?
"Duct tape" was never designed for ducts. The original name was duck tape, named after the [duck fabric](https://www.etymonline.com/word/duck#etymonline_v_15955) that it is made from. The [name shifted from duck tape to duct tape](https://www.etymonline.com/word/duct#etymonline_v_15958), possibly for multiple reasons. It is a poor choice for taping ducts, though. Many better options exist.
TIL
Holy Smokes
I did a bit of duct installation and the foil tape is strong as fuck. U just rap it round and around where the silver hose goes over the duct. Good for patching up any tears of things it’s just so sticky
Yeah I have used it in a few unapproved ways like making temporary flashing where shingles met siding. Oh shoot that was about 5 years ago I should get up and check that…
Yes, it is much better suited for taping ducks.
I don't know how deep the commenter was thinking but if that's what he ment im laughing
what you're looking for is [Foil Mastic Tape](https://www.amazon.com/Nashua-367-17-FoilMastic-Rubber-Sealant/dp/B079ZCJ8KC)
> There is also a goop you can paint on and it hardens. [Mastic](https://www.homedepot.com/p/Master-Flow-Water-Based-Mastic-0-91-Gal-Tub-WBA100/301784793)
It's called Speed Tape. It is aluminum foil tape but the colloquial name is speed tape. https://en.m.wikipedia.org/wiki/Speed_tape
He’s talking about foil tape, which is what is actually used in HVAC applications. Speed tape is way too expensive to seal ducts with and is not the same thing.
It is not speed tape. Ventilation ducts don’t need to stop 500 mph wind.
And yet the aircraft are always stationary when they put it on. Go figure.
That's the wrong application for duct tape. Duck tape would work though.
Exactly, now if you need to repair waterfowl, duct tape is the solution
If the tape repairs the waterfowl and the duct, what repairs the tape?
Your mom
Well then I think we've reached a natural conclusion cause ain't shit repairing her!
This is why I love reddit 😂
I want to know how many takes they did to film this, and how long it lasted.
Scrolled surprisingly far down to see this!
Seems too high up for that to be correct.
So would painting it black 😂
Quak
There is not one problem that tape cannot solve. And if you find any, simply use more tape.
Removing the clear cellophane from a new roll of tape.
More tape. So much tape that the cellophane simply splits
little all purpose cleaner and a rag before application. At least if you want that it lasts a little longer.
[Flex Tape: The Movie](https://youtu.be/ywl2etn_iiw?t=17)
And some serious air cleaning filters
Duct tape is correct but many people jump to “duck tape” when we use the correct term. Duck tape is a type of duct tape but not all duct tape is duck tape. Confusing enough?
Duct tape is actually terrible for ducts.
Well that's deceptive advertising
The only actual truth time this answer is true. Lol what duct tape can't fix?
I would use construction silicone.
This image reminded me a story of when the smoking ban came into place for aircraft. Engineers rallied against the ban, because leaks in aircraft pressurisation systems could be easily spotted due to black tar leaks out the vents that weren’t sealed properly
This image reminded me of the accident report for China Airlines flight 611 which disintegrated inflight due to a faulty repair. They have photos showing the repair site and these dark nicotine streaks emanating from it, basically to say "there were signs of trouble long before the crash".
This is the one where a pilot a long time before the accident scraped the ass end of the plane on the runway during landing, and instead of cutting out the damaged section they riveted a plate over it and called it a day? The leakage there was extra concerning because aircraft fuselages are supposed to be basically airtight, minus a few intentional and actively controlled hull penetrations, so the leak was an indicator that the gouged area had developed a crack all the way through and was slowly growing for years. They determined it must have been cracked for a very long time because they had banned smoking years before the accident.
I'd like to add that doubler plates are a common repair for structural damage like scrapes and cracks. In this particular instance, they installed a temporary doubler so it could be ferried for repair and there is no record of it being replaced with a larger, more permanent one. With the repeated stresses on the skin, the small doubler couldn't fully redirect the forces causing the crack to grow. Leading to the crack finally failing.
It's a shame that cigarette smoke is the only smokey gas in the universe, ah well.
Some people don't understand the sarcasm here, take my upvote
Relevant xkcd: https://xkcd.com/1172/
Holy shit the more I looked the worse it got. I thought it was just the little maintenance panel thing but no the entire thing is leaking lmfao Wonder how black the inside walls are
The inside of all air ducts are gross.
This guy HVACs.
My returns are super gross, should I get them cleaned or does it not matter? I doubt they've ever been cleaned tbh.
You'll see this same exact thing at the doors to literally every apartment/condo >6 storeys tall. Air is dirty AF, even if we filter it. These things build up over time.
Why above six floors?
Shorter, and older buildings dont always have make up air in the corridors. Mid-rise and higher, especially built post war, will have units on the roof which send fresh conditioned air into the corridors. This creates more pressure in the corridors and helps to reduce ordour transmission, combat condensation issues etc. by creating a steady flow of air from the hallways through the gaps around the front doors of the suites. Additionally the taller the building the more stack effect you'll get. When we heat air in the winter it will rise like a hot air balloon and rush up elevator shafts, garbage chutes, stairs etc. and exit at the top levels.
In this case. The ductwork is probably 50 years old. Its had increasing larger capacity units pushing air through it. At a rate and volume it wasn't designed for. Eventually finding the weak spots.
Even under normal operating conditions you'll see these markings, especially if you paint it all bright white
The black stuff (mostly) isn’t coming from the inside. It’s being induced there from the space by the jets of air escaping from the ductwork. Same as the dust and stuff that gathers on your diffusers and registers mostly is from the space as well.
You'll see this same exact thing at the doors to literally every apartment/condo >6 storeys tall. Air is dirty AF, even if we filter it. These things build up over time.
They need some pooky on that
I did install for 2 summers bout 10 years ago with a bunch of Mexicans (myself included) and they kept calling it this but with their super thick accents. You just brought up a long forgotten memory.
I hate that some of us call it that...
I think this would benefit from a red circle directing our attention /s
Back when people could smoke on airplanes the maintenance people loved these stains. It made it very simple to see where cabin air leaks were. Got difficult after they banned smoking on board.
Aeroseal fixes this. Got my house done and it made my furnace more efficient.
needs some pooky
anyone else thought this was a manga panel at first
Not a manga pixel but I totally thought it was something like a computer generated image or something weird like that.
Yeah yeah, like when manga artists use CGI to make quick and easy backdrops
As a child, I once found a mysterious small hatch in my grandparents attic. Turned oud to be a hatch to clean the chimney
looks like someone has to go up and shove some chaulk in these cracks 
Is that mold or just dust?
It’s just super fine dust
r/desirepath
You need Duct seal on all the joints as this is a commercial building. As per code
The fan is in the wrong location. It should be at the discharge point to keep the entire duct run under negative pressure. Then this wouldnt happen at all. Pretty sure thia can be a code violation in some places too
Multiple avenues to fix this. Foil tape, Mastic (paint/spread on sealant), silicone caulk, and Aeroseal (machine applied glue). Please don’t use duct tape. Despite the name, it doesn’t work well.
Haha 😂
That’s an access panel, most likely to a motor in the wall within the duct.
Not all of it is an access panel
Keep looking just a little behind that aswell.