Kingfisher wrote on Apr 4^th, 2012 at 4:42am:

I consider backfilling about two layers of mono onto the spool a necessity to prevent fireline and similar lines from spinning on a smooth metal spool. More than once I have had to perform "field repairs" on other peoples reels to correct this problem. Use back to back uni knots or blood knots to connect dissimilar fishing line. They are tricky to tie correctly the first time but help yourself by doing it in a well lit spot at a desk or work bench not in the field.

Apply a piece of tape over the first couple of winds of line on the spool.  The small white piece tape that comes with the line purchase is handy enough.

-YB