How to deal with this problem on shower tray

droopsnoot

billiepiper14 said:

Thanks will get more pics later. Only moved in a year ago & done full renovation so only just got round to smartening up shower with new trims etc. will try a good scrub later but appears more rust than grunge

If it's aluminium, it won't be rust - aluminium does corrode, but it doesn't turn red / orange like the kind of rust you get from steel. I can't really tell from the picture. 

twopenny

Maybe it is a seal that was stuck to the metal and it has disintegrated.

billiepiper14

twopenny said:

Maybe it is a seal that was stuck to the metal and it has disintegrated.

Yes could have been. Do we think I need to get some kind of plastic strip to go over it & hide it ? Thankyou 

ThisIsWeird

billiepiper14 said:

Best photo I can get. Scrubbed it and ordered white vinegar but does not appear to be gunk

Ah, it's that bevelled seal between the base and the shower glass?
That looks like either a 'rubber' sealing strip (but too thin I think), or a bead of silicone sealant - more likely.
Could you press down on it with summat hard like a blunt kitchen knife to see if it's squishy - but don't damage it?
If it's silicone, or even a rubber seal, that stain looks like mould that has penetrated below the surface, so you'll need to bleach it using something a lot stronger than vinegar.
You'll probably get reasonable results using a purpose-made 'mould-killer' like 'Astonish', but I suspect - like in my shower - the deepest-penetrating stains will remain.
Do you have any normal thick bleach? If so, try that on a few inches of that strip, and see how it works.
Ultimately, it's just a cosmetic issue, so to fully bring it up to new can be done by laying a further bead of silicone over it, finishing with a Fugi tool. Or, sticking a hollow decorative beading there to hide it!
(Yes, to re-silicone you should remove the existing stuff first, but I don't want to lead you down a path where the job might become tricky.)