PVC dinghy cleaning

[greeny]

Need to clean my pvc inflatable but it has got brown sunburn marks on the top of the tubes.
Does anyone know of anything (except for acetone or thinners) that will get rid of these marks, that actually works. I've tried several purpose made pvc boat cleaners but none have made any impression on the marks. I've also tried Cif(jif) without any joy.
Any ideas or suggestions welcome, apart from those that would destroy the fabric because they are too aggressive.

 

[VicS]

While you can clean dirt off the surface i think there is probably little or nothing you can do if the fabric itself is stained or discoloured without damage.

 

[greeny]

Thanks Vic, seems its there to stay.
I've spent the afternoon with jif and other non destructive powders including barkeepers which contains oxalic i believe, scrubbing away, but only managed to slightly reduce the marks.
Pity really because the dinghy is like new otherwise.
Stupid really to have left it without a cover last year when the old one rotted.
Thanks anyway.

 

[Graham376]

Polymarine do a good pvc dinghy cleaner but it won't get rid of the Portuguese sun UV damage you have. Make some chaps before it gets baked too much and brittle.