Fiamma drip stop , I used a similar product on my first RV and it reduced black streaks to the four corners of run off.
Perhaps prevention better than cure
http://www.agentfiamma.co.uk/fiamma-drip-stop-300-75.html?gclid=CKbT2_u7qcsCFc0y0wodD5INOg
Perhaps prevention better than cure
http://www.agentfiamma.co.uk/fiamma-drip-stop-300-75.html?gclid=CKbT2_u7qcsCFc0y0wodD5INOg