So I'm in the middle of wheel building and I find out that my spoke length calculations were wrong. LBS didn't carry odd length spokes so I rounded up. Now I know why I should've rounded down.

I've tighten down the spokes to the nipples all the way. Only if I had 2mm of extra threading, this thread would've never existed.

I'm looking for a simple solution. I was wondering what my options are which excludes replacing them.

Find someone with a threading machine? Seems too much of a hassle.

Would it be practical to throw in some washers between the nipple and the wall of the rim? I've never heard this done before nor have I seen washers for this. The only washers I was able to search for were called "spoke washers" which seem to be used between the spoke head and hub flanges.

Suggestions?