How long can copper foil sit

[Oofda]

My current project is 220 pieces.  I spent the weekend working on my project and 40 pieces into it I thought, man I don't want to copper foil 220 pieces all at once.  How long can copper foiled pieces sit?  Aside from keeping dust, dirt and all that off of the pieces would it be ok to foil as I go?

Thanks!

[Kev]

Take your time with it, it will only oxidize a bit, and the application of the flux before soldering will clean that up. I usually just lay a towel over it to keep the dust and dirt off it when I am not working on it.

[PiscesGlass]

As long as it doesn't sit for 6 mos or more it should be fine.  Foil is at it's best when it's been kept in a fairly airtight environment...I like to keep mine in a plastic baggie..the rolls that is.
I've been given pieces that someone started and never finished..and lord only knows how long they've "sat around"..although the foil was still adhered to the glass very well, it was sooo oxidized it would never solder well.  So all of it had to be removed.  What fun eh?

De