The HDG seems to have some surface porosity, so the marker gets down in a little. The acetone got about 80% of the marker off of mine - leaves a noticeable but faint remnant.
Try saturating some paper towel with the "Must for Rust", put it on the rusty area, and cover tightly with plastic to keep it moist, it should accelerate it. Porosity may apply here too.
You could also treat the whole thing with cold-galvanizing. I may try it myself since I have some of the Rustoleum version.
Viz was nice. The floating algae clumps were annoying, though. Unfortunately, my cold/sinus infection got the better of me on the night-dive and I decided to bail on today.
Try saturating some paper towel with the "Must for Rust", put it on the rusty area, and cover tightly with plastic to keep it moist, it should accelerate it. Porosity may apply here too.
You could also treat the whole thing with cold-galvanizing. I may try it myself since I have some of the Rustoleum version.
Viz was nice. The floating algae clumps were annoying, though. Unfortunately, my cold/sinus infection got the better of me on the night-dive and I decided to bail on today.