HVAC - Ductwork Question

[BigInSeattle]

I know this is completely off-topic but does anyone here know how I would temporarily remove this ductwork behind my furnace? The HVAC places I have called have all said it would be too costly for them to do it. I need to get it out of the way so I can fix a leaky galvanized hot water line above it. It is an old repair and it looks like someone has had it off before for the previous galvanized repair.

Does that sheetmetal at the joints just slide on / off? I really just need to get that center section out of the way. I just don't want to destroy it trying to get it apart.

[Robert]

I doubt very seriously that there is an easy way, sometimes you just need to start and see where it takes you. The pics really dont say all that much and dont forget there is probably insulation on the inside of the duct. Most ducts today are fiberglass mat. No matter what it should not be that big a deal since the foil duct tape can pretty much seal any leak and join any duct work.

[da prez]

At the joints a metal tab folded down is straightened on bothsides. If they do not pull off , a vise grip and hammer should remove them. If not , tear them off.
 They are available over the counter at big box stores.
  Removing is usually rough to do. Wear leather gloves.

            da prez

[hubcapsc]

Don't get your duct tape from the big box store, though.

My hvac man gives me a roll of the good stuff every time
I run out  ... they have some stuff in the parts
department of the real plumbing place near me that is
probably "the right stuff".

If the surface is clean, real hvac duct tape will stick and
stay stuck and do what you want.

-Mike

[BigInSeattle]

Yeah I figured I could just go with the rip it apart and duct tape it together method if I get desperate.

[Bret SD]

Yeah I figured I could just go with the rip it apart and duct tape it together method if I get desperate.

Taking a plenum apart won't be easy, you have the option of cutting it with a grinder and 1/16th metal blade. I've done that in the past, then used rolled aluminum as a joiner, some good caulking and a rivet gun to secure it.. then you're not relying on tape in a high pressure section of the system.
If you cut the top first and lift it you can get to the back, then reverse the order for reassembly by riveting the wall side first from the inside of the plenum, from there it's easy enough to stitch the top back together.

I am a semi-retired general contractor and not a HVAC specialist, but if I ran my plan by one he's likely shrug and say yes, it'll work in a pinch. Vulcem is great caulk, dunno if it's still around. Any good polyethylene caulk will work, I like Vulcem because it's thick and stays flexible.

Hope this helps

[Patrick]

I'm thinking that your problem is at the pipe union. If so it looks as if quite a bit of the duct work has to come apart which will take awhile.
Once you get started fixing old iron pipe it just seems to keep going and going and going till its all replaced.

[t-man403]

The short side of the duct ..... usually 8” has retainers that slide off. Sounds easy but they are usually folded top and bottom. If you can get the top unfolded reasonably straight, you should be able to pull it straight down. Get all four off and the section will slide out of the S- cleats. Goes back together in reverse order.

[Deerslayer]

Once you get started fixing old iron pipe it just seems to keep going and going and going till its all replaced.

Couldn't agree more.
that duct will be the easy part

[BradValk48237]

Might be easier to cut out and replace/reroute pipe rather than pull out duct......

I'm lazy

B