Depends on the location,if it is a cricital structural area it may be better to reinforce the whole area,rather than just doing a patch job,and yes you can just repair a small area,but I would do a complete check on the frame,and also remove any loose epoxy,and refinish those areas. I would say every spring when you take your Delorean out for the season do a complete frame check to make sure you get no surprises. Claude 000570 3/81