Hull cleaning/streak removing
OK, let me preface by saying that the hull gelcoat of our Sabre 34 has lots of shine still. Normally, we'd just apply a coat of Collinite Fleetwax and call it a day. However, after washing the hull today with boat soap and a light brush, we noticed there are a number of black streaks remaining, along with some exhaust stains on the transom. They aren't terrible, but we'd like to get rid of them before waxing.
Since boat soap didn't do the trick, we tried a black streak remover (barely any effect), and we tried Roll Off and Interlux Heavy Duty Stain Remover. Both worked to some degree, but took a good bit of elbow grease with a rag or paper towel, and the results were uneven.
On a whim, in a spot that's not very visible (under the transom), I scrubbed some of the streaks with the backside of a sponge--the scotchbrite part. I would normally not use something like this on our hull of course. But the thing is, the streaks just wiped away. I mean with like no effort. And there was no "product" on the sponge.
So my question is, instead of trying cleaner after cleaner, are we just not using the right implement? Should we be using a tougher brush or something? We don't want to scratch the hull, but it seems like a little abrasive is working much better than the cleaners. Again, not saying we should use a scotchbrite pad on our hull, but is there something we should be using?
Thanks for your help!
1984 Sabre 34 Mk I