Depending where the crease is and the size of the break, you may have luck with adhesive copper foil used in stained glass windows. You can get it at craft stores.

I do second David's suggestion of using the edge of an x-acto knife to scrape rather than sandpaper for cleaning up the break.

-Jarrett
On Jun 5, 2012, at 7:56 AM, pickle vanagon wrote:

> 
> I found an old post of Ken Wilford's suggesting Window Defogger repair kits
> as a way of repairing the foil (one of these:
> http://www.amazon.com/Permatex-15067-Window-Defogger-Repair/dp/B000HBI9YQ/ref=sr_1_1?s=automotive&ie=UTF8&qid=1338899609&sr=1-1