Tweet
I used a press with hard polyurethane rubber to form the hole flanges. (See John Snapp's youtube video)
The first picture shows how much bow was in a rib right after pressing round flanges.
I built a jig that uses a 3/4 x 1/16 aluminum strap (home depot) with holes at each point that I wanted a flute. The rib was placed over a form block (also with notches), then the band was laid on top. The band is tightened with wedges at the end. The band holds rib against form block. I then lightly poke a hardwood dowel thru the hole and make a flute. The flutes will be the correct amount since there is no material to take up because of the tight band.
There are many ways to do this task. This is what I chose to do.
The first picture shows how much bow was in a rib right after pressing round flanges.
I built a jig that uses a 3/4 x 1/16 aluminum strap (home depot) with holes at each point that I wanted a flute. The rib was placed over a form block (also with notches), then the band was laid on top. The band is tightened with wedges at the end. The band holds rib against form block. I then lightly poke a hardwood dowel thru the hole and make a flute. The flutes will be the correct amount since there is no material to take up because of the tight band.
There are many ways to do this task. This is what I chose to do.