If it's the actual tape that's ripped, torn or whatever you may be able to get hold of a splicing kit available from places such as http://www.keene.co.uk/
From their website:
Quick guide to splicing video tape
Trim away all damaged/crinkled tape and discard
If the tape has snapped near to one end, trim out all the damaged tape and make the join to the leader.
Clamp the tape ends in place so that they overlap and make a 45 degree cutFor video tape put the joining tape on the side that faces towards the tape housing only and verycarefully trim away any excess with the blade
Carefully wind it back into the housing, play it once only (to make a copy) and then discard it Remember that this is a risky process as video heads are very fragile!
Craig Gilman, August 2005
