Black spots on marine vinyl

Hello, I am a leather repair tech who has had an opportunity to do some work on boat seats. The main problem is lots of both black spots and blotchy dark areas on a cream colored vinyl. I assume it is mildew. The boat owner claimed it was spider poop and he seemed to be serious. No kidding. I tried cleaning with SEM soap and 303 fabric/ vinyl cleaner which removed about 50%. Is there a product/technique that might give better results or remove the remainder?

I attempted to remove some black spots with acetone on a q-tip. Took a number of strokes, but removed spots along with some of the color. Not a viable option. Didn’t try naptha.

On the final photo, I cleaned above the seam and below the seam was untouched.

Thanks for any suggestions.

Tips for Vinyl:

Soak with Prep-7.7 for 72 hours then rinse off sticky residue with Clean-3.8 follows with Rinse-3.0.
Finish with Protector-B/B+ for a more effective non-stick surface.

Vinyl Restorative Care:
Restorative care is the ultimate corrective or salvage care system that removes accumulated soiling including aged conditioners to its original OEM finishes. Accumulated soiling that fills creases is often mistaken for cracks. Vinyl restorative cleaning of accumulated soiling is performed by Prep-7.7. It works by chemical reaction to emulsify soiling through its penetrating, lubricating, and suspending power. Its viscosity facilitates coating the surface for effective dwell time. Horsehair detailing Brush-1 is recommended to worked into heavily soiled areas sufficiently to avoid excessive agitation that might damage already weaken finishes, especially on heavily used areas. For extreme cases, the Prep-7.7 can stay continuous for up to 72 hours to do its work safely.

1st step - Restorative Cleaning:

Instruction . . .
1- Apply Prep-7.7 onto the surface with a foam brush and agitate with horsehair Brush-1, ensuring a uniform application over the entire surface a section at a time.
2- Allow a dwell time of 10 to 30 minutes (even up to 72 hours) or before it dries prior to towel extraction until it shows clean.
3- Sticky residue is removed by Clean-3.8 with gentle brush agitation and towel extraction until it shows clean.
4- Remaining residues are spray rinse with Rinse-3.0 and towel extract to a squeaky-clean.
5- Let dry and inspect for satisfaction, otherwise repeat Prep-7.7 application with a longer dwell time as necessary.

2nd step – Protecting: Instruction . . .

1- Apply Protector-B after shaking well spread with lint-free towel and is ready for use when dry.

Attachment 10304

https://www.leatherdoctor.com/leathe...-care-kit-ap3/

Attachment 10305
Roger Koh
Leather, Skin, Hair, Eye & Acne Care System Formulator
Consultant / Practitioner / Instructor / Coach
web: www.leatherdoctor.com
forum: www.leathercleaningrestorationforum.com
email: [email protected]