[quote=POPS;827901]Yep, Cut the gel coat with acetone until you get the spray you like. Test spray on smooth vertical surface - no runs. Use a good, good bit more catalyst then you think. Get the scratch onto the horizontal if possible. If not, wait 10 minutes or so between light coats - no sags... no over spray outside your tape off...

Just a note that using acetone was mentioned to reduce gelcoat...most manufacturers now recommend styrene or even better MEK as thinner. If doing a large area pros will use patch aid (http://www.bottompaintstore.com/patc...t-p-12410.html) or similar products (both the wax and thinner).It is believed that acetone has a tendency to yellow more over time and tend to develop cracks.