I'm going to show you how to make an smooth aluminum siding corner for siding the is no longer manufactured.
I bought a house a couple of months ago, that had quite a few siding corners missing (over 10). And since the siding appears to have been manufactured in the 60's-70's, I had no choice but to make my own corners. Since no one carries repair pieces.
Step 1: Gather Materials and Tools
Materials you'll need:
Aluminum coil stock (I used 6" x10' stock, and it was a couple of bucks at Menards.)
Metal primer spray paint. (Menards)
Loctite Power Grab Adhesive
Sheet metal pliers
Two bar clamps
2 or 3 pieces of square scrap lumber
Step 2: Pattern Time
Now is time for the painful part. Pulling off a corner from the house in order to make a template. If a corner is already loose or laying on the ground (it does happen) you're in luck. But if not, you're going to have to remove one from the house. This is the not fun part since there is usually a blind nail at the top of the corner holding it in place.
So now that we have the corner off, use the pliers to flatten the corner to make the template.
Cut a segment out of the coil stock and use the old flattened corner and trace the outline onto the blank. Then use the tin snips to cut the blank out.
Step 3: Bending
Now that we have a couple of blanks cut out, lets bend them into a corner.
Keep in mind that you need to make the bends in a specific order, or you'll run into trouble when bending the lip. I learned this when trying to make the first prototype.
Step 4: Bending - Length Wise
The first bend you are going to make is the length wise bend. Make sure to center the piece along the width within the scrap. Clamp it tight. Then bend the over hanging portion to a 90 degree angle with you hands. This is the only bend in much it doesn't matter if you make the bend toward yourself, or away. Sure you can use another piece of scrap to make the bend, but it didn't help much on this crude bending jig.
Step 5: Bending - Lip 1
Now we can bend the first part of the inner locking lip. Grab you sheet metal pliers, and starting on either side. Make an inside 90 degree bend to form the bottom of the inner locking lip. Do the same operation on the opposite side.
Step 6: Bending - Lip 2
Now we make the final bend. Take your pliers and starting at either end, make the final 90 degree bend, toward the inner section of the piece.
Step 7: The Final Corner
We're now all done, and you can install the corners onto your house. I personally found it easier to attach the new corners with Power Grab, instead of trying to nail them up. This is also the time to prime the pieces, using either an automotive spray can primer or a high quality bonding primer.