DC metal ducts - how to secure to each other

[Eduard Nemirovsky]

Start putting together DC ducts. It is 26 Ga snaplock pipes from Oneida, very good quality by the way.
Two questions - best way to snap this pipe from flat to round? Right now it take me at least 5-10 minutes for most stubborn to lock it (((.
And another question - in my old system I used rivets. Should I start using SM screw? Or just silicone and tape?
My concern with rivets - if I need to redo it - drill out rivets - hole become big - need to use big rivets ?
With 1/2" screw - big piece inside of the duct, easy to clog?

Thank you,
Ed.

[Jim Andrew]

Is your pipe not curved? The pipe I have bought locally is curved, and not hard to snap together. Far as screws or pop rivets, I have used both. Last time I worked my system over, removed the screws and used small pop rivets. Just put the rivets where you can easily drill them out. They come out easily if you want to take them out. I also used furnace tape to seal the joints.

[Lee Schierer]

I would use aluminum tape to join and seal the sections together. It should provide a secure air tight joint and you can take it apart later if necessary.

[Ken Fitzgerald]

I used pop rivets and then covered the seams with aluminum tape to seal any potential leaks.

[Kent A Bathurst]

I have no idea how to snap the sections into "round". Eventually they go together, but seems like magic - I have not figgered out the correct technique.

On joining section-to-section: I use 1/2" self-tapping sheet metal screws. I know this is "wrong" because it has the screw point protruding into the waste stream, and can cause a build-up, but it is very small, and has never caused a problem.

Then - always seal the joints with metal tape - prevent leaks.

[Mike Chalmers]

I found that it was much easier to lock the seam if I got one end in and used a small C clamp to hold it while I worked on the rest. Before I did that, I could not get the seam to join and close at all.

[Brian W Smith]

Rivets and duct seal here on male/female or sleeve it.......no tape.

[roger wiegand]

Pop rivets and duct tape here-- UL 181B-FX listed duct tape, the kind you actually can use on ductwork, before we start a thread on the inappropriate use of duct tape on ductwork. Drilling out the rivets is easy when you need to. I've completely taken apart and reconfigured my system when moving shops, so lots of experience doing that. First time I sealed with silicone caulk. That mostly just made a mess, though it seemed to work well enough. Tape was easier.

[Roy Harding]

When I was putting my system together (also 26 ga), I used a strap clamp to draw and hold the sections into "roughly round" shape - it made getting the snap connection easier, as I was no longer fighting to keep the sheet metal in shape. It was then a matter of lining up the "snap lock" section and pushing DOWN on the seam until it snapped together - the section then recoiled into its final shape. I then sealed the seams with furnace (aluminum) tape.

[Phil Thien]

Just a comment on drilling-out rivets: Use only as large a bit as you need to in order to break the rivet. You aren't drilling into the steel, only the aluminum rivet.

So you don't need to upsize the rivets when reusing ductwork, just keep using the same size.

[Ole Anderson]

Just a comment on drilling-out rivets: Use only as large a bit as you need to in order to break the rivet. You aren't drilling into the steel, only the aluminum rivet.

So you don't need to upsize the rivets when reusing ductwork, just keep using the same size.

Agree: Drill out 1/8" rivets with an 1/8" drill. I started with self tapping screws, then removed them and replaced them with 1/8" x 1/8" aluminum rivets at 4:00, 8:00 and 12:00. Finished off with aluminum duct tape and silicone on the places duct tape wouldn't lay flat.

[Eduard Nemirovsky]

thank you guys for sharing experience. Yesterday I finally got to the point locking snap-lock duct in a few minutes. 6" much easier then 5" (((. I will go to use rivets and tape.
Thanks again,
Ed.