Best Of

I was thinking you needed the machine to do it on a curve, you can do it albeit rather tediously on a straight section with a brake. Now that i think about it more, i bet the curved pittsburgh is done on a flat piece that is rolled in to a curve after and the 90 that locks in to it is made around the curve with something like a hand seamer. i don't know if it is a regional thing, but this is how most ductwork is made around here.

There is a machine that can form that on the edge of a piece of sheetmetal with a series of rollers sort of like a continuous gutter machine.

Just cut the factory ends off & reflare them. (That's what the groove in the tubing cutter wheel is for! I didn't know!!) If you take a look at the factory end & a flare that you've made, you'll see what I'm talking about.

You can braze them in if you want, but that's a lot more work—unless you live in Chicago. I hear they're not allowed to use flares, or weren't. Do flow N₂, Never had a problem with clogging the screens with that.

I'd be super concerned about people reaming the copper if that were the case.

mattmia2 said:

Mad Dog_2 said:

Oh yeah?  Leakers?  Reflare em or braze em?  Mad Dog 

No brazing on minis!

why not? if you actually trickle N2 or CO2 as required and heat sink it before the unit i don't see a difference between the 2.

Even with N2 there is the potential of copper oxide forming. Minis DO NOT have the safety of filter driers just several very fine screens. It doesn’t take much to plug one of these up but is a nightmare figuring out what one or two ARE plugged!

When you asked about this i was going to say you should make friends with a machine that can roll a pittsburgh but looks like you won't need that.

Mad Dog_2 said:

Oh yeah?  Leakers?  Reflare em or braze em?  Mad Dog 

No brazing on minis!

why not? if you actually trickle N2 or CO2 as required and heat sink it before the unit i don't see a difference between the 2.

The factory flares are only there to hold the nut on during shipping—& they fail at that from time to time. Since you're supposed to discard them & use the nuts from the unit anyway, I dunno why they even put them on.

How did you keep the powder coat on the grill on that lennox from peeling and rusting?

Cut out and replace the factory flares on that line set!