How do you repair feathers?

[grnidone]

My rooster isn't a show bird, but his tail feathers are so pulled apart from the wind, he looks ratty.

I've tried preening them, but the feathers still look torn apart.

 

[ChickenCanoe]

I don't think they are repairable once tattered. The way they are repaired is when they are replaced after molt.
Look for a nice coat again by mid winter.

 

[I Love Layers]

Pluck them out and they should start growing again in about 6 weeks. Or you can wait until he molts next