by Chuck Doyle, February 2009
I've been fighting the two upper cowl pieces for the Travelair and making slow progress, First you must have a form or buck to work with, you just can't build a piece in outer space.
Use a shot bag and forming hammer to ruff out the shape for the material before any wheeling is started, I had a difficult time hammering mostly because I'm right handed but could only work with my left arm.
Check, pound check and recheck you rough forming, I is far easer to work the material up to you form and if you go to far it might end up in the scrap pile?
Select the anvil wheel that is closest to the radius of the piece your working on.
Start with light wheel pressure and work out the hammer marks, do not let the wheel fall off the edge of your work, check your work on your buck.
Take your time!
Don't get in a hurry, check you work on the buck and on the airplane. Outside profile gauges are very helpful as well so you don't over stretch your piece.
Your material will work harden after hammering and wheeling so it is sometime necessary to anneal the piece, for this part I'm using 3003H14 0.032 thickness.
Use the standard W pattern keeping it close or you will get ripples in your work.
Did I tell you to check your work on the buck and the airplane? than check in once more before going back to the wheel.
Getting close, now don't screw it up! and be careful not to over stretch the piece.
I use masking tape to hold them down too eyeball for final fitting, this is the most difficult part of the whole project and the most important, easy as 1, 2, 3 right?
I didn't want you to think I didn't have any trouble with these so here are just a few of my rejects! Enjoy your day and...
See ya Around the Patch!