Transferring Files Between 3DS and Wii U via SD Card

[ShinyLatios]

So I got the Wind Waker HD Deluxe Wii U (which means I've got a total of 32 GB there), and I was wondering if I ran out of space on my SD card if I could try transferring some of the files to the Wii U for storage and then if I want to play the game again just transfer it back onto the SD card and play on the 3DS (if that makes sense)?

 

[ShinyLatios]

basically the question is if I can use the Wii U to transfer some files to backup 3DS save game data if my original post was too confusing. Does anyone know on this?