How to grind absolutely flat surface?

[alexkuzn]

It's hard to make a flat surface with my 1" wide belt.
Is large milling file can help achieve nice uniform surface after grinding on 1" belt.
Do you have any recommendations on this? Do you know what file I would need?

Thanks,
Alex

[Ed Caffrey]

You can achieve a very flat surface with files, but the issue then become can you keep it flat through all the sanding steps required to get an acceptable finish. The 1" belt is certainly a VERY difficult thing to achieve true flats with. Even with files it will take some practice and patience to develop the skills.
As for the type of file(s), a large mill bastard file would be a good starting point. Two things to remember when working with files...... 1. Purchase good quality files such as Nicholson, and 2. Keep a file card handy, and use it often to clean the file of shavings that will otherwise leave nasty, deep scratches on your work piece.

[alexkuzn]

Thanks for the advise.
What would you get?
12" by 1 5/32" or 10" by 31/32" mill file?

Thanks,
Alex

[Ed Caffrey]

I would think that an 8" or 10" file would be plenty large. Eventually you'll wind up owning many files.....from the really big ones, all the way down to needle files.

Seems like for every job we do, there's a specific file size and type that works well for it.