bending 3/8" channel

Anybody got any tips on how to bend the 3/8" channel that the boot cowl attaches to? I need to replace most of mine in the cowl area, what's the trick to bend it without kinking it? Hire the job out? Jim

I buy it from Wicks Aircraft. It's easier that way, cheap too.

Steve

A clarification-I do not want to bend it in the form of a channel, I want to bend the channel around and under the belly of the cowl etc. Jim

I have formed the "Piper" channel by using my drill press as a press(drill press off of course) I used a piece of 1/4" scrap steel one inch wide with one end rounded off by a belt sander and welded to an old 3/8 bolt. With this chucked in the drill press I use a couple of wood blocks spaced about four inches apart and with the tooling pressing down in the channel I move the material back and forth with my free hand taking small bites at it with the press, the 1/4" fits down inside the channel fairly well and with a little practice it works well. This worked for me.

Forming Channel

I made a crimper out of a pair of pliers by cutting a groove (length wise) in one jaw and welding a wedge on the other jaw that fit into the groove. I measured and marked the spacing at 2-3" and crimped both sides of the channel directly across from one another. The other way is to use a shrinker if you can find one with jaws small enough to fit inside the channel. Crash

Gentily pushing/pressing will work for the side and bottom curves. Just take your time and work slowly. The sharper curves at the lower corners will need a fluting pliers like the one Crash describes. I have one made from a Vise Grip with 3 pieces of 1/8" round stock welded to the jaws to form a "V". The Vise Grip is easier on the hands when working steel, though not really nesessary for the light channel. If you don't want to make one, any good aviation tool soarce should have fluting pliers of various sizes.

Make sure you have the boot cowl you will be installing available when you make the channels to assure a good fit. If you don't get it right, you will create a LOT of problems for yourself later in your project. I would also "dry fit" the windshield, instrument panel, and the panels behind the boot cowl at this step. It is much easier to make any corrections at this point.

Thanks for the help. The lower corners is my main concern, I will make a pair of fluting pliers- that seems to be the only option. Am going to use the old boot cowl-not perfect but have seen lots worse. I may to change to a square windshield, am working on a PA-12, I am still investigating exactly what is involved to do this. Possibly a skylight, thanks for the advice. Jim

A stove pipe crimper works great. I built my own and that is all I used.

Boot Cowl Fit

To make the boot cowl fit tight, without scallops between the screws, you need to mount it with the panel and push panel all the way up with spring clampsto take the slack out of the bottom and sides of the cowl. I use nut plates and machine screws in the 3/8" channel to fasten it. Crash