My home is about 150 years old and the wood shutters are original.
The shutters were recently painted and we noted that there was significant damage to the tops of the side rails where the end grain is exposed.
Water penetrated the end grain and speeds the deterioration of the paint and the wood.
I needed about 13 pairs.
Caps that are available commercially did not appeal to me. They tended to lap the faces of the shutters a minimal amount and therefore used screws to secure the shutters at the top. This doesn't seem to be too good for keeping water out.
So, I decided to make my own.

Step 1: Materials and Tools

I utilized the following materials and tools:
- Copper sheet (16 oz.), purchased from a roofing supply company
- Copper nails, purchased from Home Depot
- 30" metal bending brake, $59.95 from Harbor Freight (No. 67240) purchased specifically for this project, but will be used for others
- Electric sheet metal shears, $29.95 from Harbor Freight ( No. 92148) purchased specifically for this project, but will be used for others
- Tin Snips
- Hammer
- Pliers
- T-square, straight-edge and thin tipped Sharpie

Step 2: Layout and Cutting

I used a t-square to lay out approx. 3" strips from a 24" wide roll, marking the lines with a thin-tipped Sharpie.

Using the electric sheet metal shears, I cut the strips and then cut them to length (approx. 19 1/8")

I then used a straight-edge to lay out the bend lines for the 1 3/8" wide x 17 1/2" long shutters. My overall 3" x 19 1/8" copper strip allowed for approx. 3/4" overhang or face on the cap.

I snipped the ends of each strip at locations which would be the ends of the front and back faces of the caps.

Step 3: Bending

Next the trimmed and snipped strip is placed in the bending brake and the two long sides are bent to 90 degrees.

The two snipped corners on each end are gripped close to the corner with needle nosed pliers and folded inward.
Then the two ends are folded up into place and the snipped corners folded back to their final position.

Step 4: Installation

The caps are placed onto the tops of the shutters and a steel nail is used to start the hole at the two corners on both the front and back faces, through both layers of overlapped copper.

A small copper nail is driven into the starer hole to secure the cap in place.