Longeron Forming
JimMac,
You will find several posts in "Search" under Longeron Bending. The ones most helpful to me were the descriptions of the "Orndorff Method." I used it and it worked great. No hammering required to bend the Longerons. They are both bent at the same time, come out identical, and have no twist. Only takes a few minutes. Here is a summary of the Orndorff Method.
1. Mark a series of lines about every inch along the bend and label them 1, 2, 3, etc. This is so you can see where to add or subtract bend when compared against the template.
2. Put about 6 strips of duct tape, one over of the other, on the top and side of each vise jaw. Just cut a strip of tape, place on the top then bend down over the jaw face. The tape is to prevent dents to the Longeron flanges.
3. Bend both Longerons at the same time using the following method.
a. Clamp the flanges of the Longerons securely together in a "T" configuration. I used "C" clamps.
b. Place Longerons in a vise with the "T" shape down.
c. Leave vise loose enough to slide the Longerons.
d. Push down on Longeron on each side of the vise to bend some curve. Unless you are really strong, a person pushing down on each side works best
e. Slide the Longeron a few inches at a time and keep bending. Lift Longerons from vise frequently and check bend with template. If a "C" clamp gets in the way of the vise just move it.
f. If you over bend, just turn Longerons over and take out the overbend.
4. I only had a 5" vise and was afraid it might break if used with a socket to squeeze open the 90 deg. angle. I cut off about a 4" piece of Longeron, put it on top of the end to be opened, and I hammered on the cut-off piece using a small sledge hammer and anvil. That worked but did take a bit of pounding.
Cordially,
Fred Carnes
