Originally posted by benncool Yes you can make any fitting that you can make with sheetmetal. To do ductboard correctly you need the right tools. Our company went to a one day school put on by Owens Corning and they showed us how to do it. We also have a Glassmater machine so that helps
Don't use v-grove duct construction use the shiplap method. All fitting are cut from a pre-assembled section of duct. If for instance you want to make a transition from 20x12 down to 16X10. Then you would first make a 4 foot section of 20 X 12. Staple and tape it. Then from this section you cut the one end down to the smaller size. Once you see it done you will think it is a piece of cake.
90 deg elbows are a sap. Again start with a full assemblied section of duct. Make a 45 deg mark on two sides with a magic marker. Straight lines on the othe 2 sides. Run the male/female tool along the marks to cut. Rotate one section and you have it. Don't forget the turning vanes.
SMACNA has a manual for fabrication of fiberous ductwork. Also all the manufactures have manuals.
Ductboard if made and installed correctly is a beautiful thing.
I already showed THE picture once this month. Visit my website I have a picture of some that we did.
There's another method for making 90's out of shiplap duct. cut the duct in two making allowances for the throat dimension. Cut the side out of the duct, the same size as the male end of the duct board. The other peice of duct with a male end gets fastened into the side,into the shiplaps. The peice cut out becomes the endcap for the 90. This will only work on shiplap.
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