So, you're on a raid of Scotland's feudal communities, your longboat cruising through the northern seas, the warriors cheering as the coastline comes into view through the fog when you realize (gasp!) that you've forgotten your helmet. now what?

Fortunately, here are instructions for a stylish chapeau that at least kind of looks the part.
You'll need:
-bicycle fender
-a leather (or comparable material) belt
-duct tape
-bifurcated paper rivets
-a tuque (beanie for you non-canadians)
-wire/thread or something thin and tieable.
-large button
-cardboard
-cable tie

for tools-(I used a leatherman, but specifically.
- metal shears
-scissors
-file
-knife (basically any kind)
-measuring tape (optional)

Step 1: How Big Is Your Head?

cut the buckle and the perforated part off the belt. if you use a braided belt, it looks cool, but I wasn't interested in tying up the loose ends. anyways, you now have a strip of leather of indeterminate length.

Put on the tuque and fold the brim up, like with regular use. now, pop a strip of cardboard into the brim that goes all the way around your head. cut off excess. now, if you're impulsive, like me, wrap the belt around the outside of the brim and try to mark where it overlaps. try not to draw on your face. I made that mistake so you won't have to. If you're more cautious (sensible), measure with a tape measure.
Cut the belt so it goes all around your head with 1 inch overlapping. Then, put two holes into the overlapping leather, and bind it with the cable tie.

now, take the bike fender and flatten it a little. I used a metal bowl and perseverance. Measure your head from front tuque brim to back brim, and then cut the fender to this length.

Warning: Sharp Things Are Sharp! the metal can be jagged. file it down smooth and wrap the sharp end with duct tape

Step 2: Aesthetics Yes, Protection No

On the back of the belt, mark regular holes in the centre of it. Mine are all about 2 1/2 inches apart. stab though the belt with a knife. Turn the tuque inside out and connect the brim on opposite sides with the paper rivets, then fill in the rest. This prevents it from bunching. Turn the brim back over and slide the cardboard back in. This protects your head from the rivets and also makes the brim more prominent. The cable tie should go in front.

Step 3: Recycling Bicycling Viking

Bend the fender some more so it does not spring back, and put the wire through the button, through mounting screw hole and tie it to the zip tie. Use tape to keep wire from being scratchy or hanging in your face-y. tuck the back of the fender behind the brim and then you're ready to raid something.