can anyone suggest a good method to clean the outside of these tanks please. mine is very dirty after  years of use.

Autoglym bumper restorer (I am not sure if that is its exact name) does a good job of making polypropylene tanks look better. Scuff marks can sometimes be removed by scraping with a stanley knife blade then warming the area very carefully with a hot air gun.

Buy a New 1

I have one bike with the polypropylene tank and this is faded and what ever I seem to used just looks drab, dirty, and awful. I have recently bought an alloy tank and am planning to dump the plastic one.

A couple of my bikes have white plastic mudguards.  These get scratched and the scratches seem to attract the dirt. I have found the best cleaner for these is Mr Sheen spray polish. An ample amount applied to the mudguard and then buffed up with a soft cloth and these come up looking as clean as new.

Stuart

Mmh first you need to take away all dirt. Thus is done the best and easiest way by using car wash shampoo and a smooth brush. Take a big bucket and wash there the tank with much hot water and shampoo. It's astonishing how much you get off. Then there might be some grease oil or others debris left where you need something differnent more a solvent like.

Here I had good result with acetone on a fresh rag just applied to the cloth then once wiping form top to bottom. Never use used parts of the cloth twice.

Then you will have a dull and partly even whitened gas tank. Now a short treatment with a heat gun with about 200 - 300 deg Celsius and the dull surface will melt up to a silk glosse surface. (All gas has to be drained in advance the drained gas tank should too be stored with cap removed for at least two days the opening should be facing down).

Done ... it needs some skills especially the last step. But I don't know a better way to sort the rough surface of the plastic tanks.

You might try out the handling of a heat gun before with an old scratched fender or likewise plastic.

Any discoloring of the gas tank can't be removed.

 

 

 

 

 

 

 

 

15 hours ago, oni nou said:

Not sure if D of 2 means Autoglym vinyl and rubbercare but even if not then that stuff makes every type of finish on a bike[Especially plastics and rubberparts] look absolutely mint......OBVIOUSLY DO NOT SPRAY IT ANY WHERE NEAR YOUR BRAKES.

USE some on your tank when you have cleaned it and it will improve the look of it no end.

The proper name for the stuff I advised is Autoglym Bumper and Trim Gel. I guess the vinyl and rubber care is pretty similar, may have addend scent to make your tank smell nice.