8" to 7" Round Butt Joint Sheet Metal Hack Emergency Use Only

A failed concentric 8'' x 7'' diameter fitting on the wood fired forced air furnace's flu and the impending extremely low temperature predictions for the next week require a rapid repair. Normally another concentric fitting would have been fabricated, but the time restricition requires that normalcy be abandoned and another route be taken. That route takes us to a butt joint that is not necessarily accepted as a viable duct fitting even though I have seen a pretty good number of them in the field. In its final form however, it is actually a stronger fitting than the factory made concentric fitting. Both components are made of 24 guage material. The one is a factory 4 piece adjustable 90 degree elbow factory made of 24 ga. galvanized. The one made in the video is 24 ga steel. The steel is much stronger than the softer galvanized fitting.
The tinners anvil used for the first time today in a video for YouTube. The same can be said for the 'set' tool for a double fold over lock joint....otherwise known as a 'flat lock' seam until it is set down with the appropriate 'setting tool'. At that point it becomes a "grooved flat lock' seam. It is a joint used by myself hundreds of times over the years. Instead of locking it in with the steel punch, I have many times soldered the joint with 50/50 when the joint was used in fabricating a fuel tank or any tank or container used to hold liquids.
Now when it comes to the installation of the end piece, the dove tailed design was selected because of the type of scrap metal used. Steel flat stock, at 24 ga., is much more difficult to work on with hand forming tools and snips. The hand crank 'beader' that would normally be used works best on the softer galvanized metal. This is not a crimping beader, it only takes about 3/16th'' of the outside edge and turns it into a 'V' shaped groove which allows a round flat piece of material to be dropped into the 'V' then hammered over to lock it in place. The second reason dove tails were used was that the outdoor temperature was dropping fast...much faster than I could fabricate a proper concentric reducer !!
Another cameo appearance of the oldest of two PEXTO crank operated crimping tools made the line up for today. It puts a nice almost perfect set of crimps on the material, and as you will see in the next video, and they slip perfectly into the 8'' diameter as desired.
In retrospect, this turned out to be quite the boring video....no loss of blood, no cussing, broken bones...nothing exciting at all. Unless you happen to be looking for just this style of joint and how to make it...then it could be considered extremely exciting !! Yeah right, about as exciting as watching paint dry or heaven forbid a tennis match. LOL. Sorry tennis fans...but I only watch videos of that to put me back to sleep......well, golf too. Don't. Shoot. Me.....

Видео 8" to 7" Round Butt Joint Sheet Metal Hack Emergency Use Only канала Tractorman44