This ornament is a creche' I saw on eBay. Antique square cut nails (2nd photo in this step) lend themselves to artwork of all kinds. See also my Instructable on making a Jerusalem cross for hanging on the wall.
Square cut concrete nails are now available in the USA as a standard item at Lowe's and Home Depot stores. These nails are heavy enough to weld without burning them away. I have made this ornament using 1/16" #6013 rod on a 220 volt stick welder and also at a setting for 1/8" stock on a flux core wire feed welder.
Step 1: Begin With the Shed Roof
I weld small parts on a piece of aluminum angle clamped in a vise. The aluminum allows me to weld small parts and takes away excess heat that would cause the part to melt and blow away. Place two nails tip to tip at an angle associated with a shed roof. Weld them together lightly. You do not need a lot of strength. At the same time, knock the slag away before disturbing the setup to make certain there is fusion between the two pieces.
Step 2: Weld the Floor of the Shed
Place two more nails tip to tip and weld.
Step 3: Weld Two Nails for the Shed Walls
Position the roof section so you can weld the nails for the walls over the aluminum angle. Clamp the pieces to the aluminum so the assembly remains as flat as possible and does not twist.
Step 4: Weld the Floor to the Walls
Eventually you will need to decide if the side with the welds is the good side, or if you want the other side to be the good side.
Step 5: Bend Two Nails for Mary and Joseph
Concrete nails are very hard until softened with heat. Place three nails on a brick. Heat two of them just beyond halfway a bit closer to the pointed end until a dull red. Heat a third nail the same way about 3/4 inch down from the head. The third nail will be the manger. It needs to be softened so you can cut it with a hacksaw. I used a MAPP gas torch to heat the nails. Allow them to cool so you do not burn your fingers.
(I apologize for the blurry photo, but the orange and black switch on my bandsaw is sharp.)
Step 6: Weld the Figures in Place
Plan the positioning of the two nails representing the figures so the heads are not touching when in place. I probably should have bent the nails a little less.
Step 7: Saw the Nail for the Manger
Once the nail has been heated it can be sawn quite easily with a hacksaw.
Step 8: Weld the Manger and a Halo in Place
The cut piece of nail is the manger. A flat washer makes a halo to show the presence of the Christ child.
Step 9: Add Braze for Color on the Halo
I used a MAPP gas torch to heat the washer and braze it. The braze adds some golden color that makes a nice halo when it is cleaned up. Sometimes I have applied too much heat when brazing and the final color resembles wrinkled copper more than smooth brass.
Step 10: Clean Up the Ornament
Chip away at the welds with a welder's hammer to remove any remaining slag. Go over the ornament with a wire brush wheel. Try to remove any white powdery deposits from the brazing rod flux. You may spray both sides of the ornament with a clear shellac to protect against rust.
Step 11: Hang It on Your Tree
Wrap some wire around the weld for the roof pieces. Cut it and add a hook. Hang it on your tree, or give it as a gift. These are fun as a welding project, although I like the Jerusalem cross that I linked in the Introduction better. But, women seem to like these creche's very, very much. They also like the Jerusalem crosses, but they especially like these.