Varchar field is null-padded after converting from Binary

[Gazelle]

I have a PX job that reads in an entire record as a single binary column.
The binary column is later passed to a Column Export, that converts the binary column into a Varchar(4000) field, which is then output to a delimited Sequential File, with variable-width records.

The problem is that the text file is right-padded with null characters.

How can I output the original binary field as a variable-width Varchar(4000) field?