Black Streaks

Has anyone got a solution to the black streaks I am finding down my Mezan after rainfall. 
They are surprisingly hard to remove, kitchen cleaner seems to work but leaves a slightly yellow tint to the GRP and long term I don't think that's good.
I have tried wax polish after cleaning, but every time it rains they come back.

Anyone got any ideas ?? Even obvious ones may help !!!

Note the ones on the front of the luton are the worst 'cos you cant reach them !!!

Here is a link to a previous thread on this, I've used these ideas plus any of the waterless cleaners remove them to, had mine from Aldi.

John.
https://www.autosleeper-ownersforum.com/t8431-black-marks-on-bodywork

Well I'm going to have to start getting the marks off mine soon. Have bought black streak remover and collinite wax but keep looking at it. I think the rain keeps putting me off.

Have been using baby wipes,they work very well .As I put in a previous post on this subject "if they are safe to use on a baby's bum" they can't do your paintwork a lot of harm .

In fact while I'm on the subject, I have what appear to be streaky runs on the black plastic "bumper" at the rear of my Mezan. I tried Isopropyl and all sorts of kitchen cleaners which appeared to work, but the runs came back after about 10 mins drying time. I finally ended up with good old T Cut and plenty of elbow grease. This left the 'Van looking pretty for a couple of days........ and then it rained........
Anybody got any ideas on how to make the bumpers stay looking nice ????
Many thanks, Richard

Hi ho.. For some years I have been using Fenwicks Motorhome Cleaner and to remove the black steaks I always clean them off by using neat Fenwicks Motorhome Cleaner. This has never failed and using it neat has never marked the the van in any way.

Best wishes.    Eddie.

Ooops.  Forgot to mention that I use Back to Black to keep the black  parts of the coachwork looking smart. Back to Black or like products are available in Halfords and the like motorists discount stores. Whatever NOT to do is to put polish i.e. Mer etc on the black parts.

That's all for now, unless I have forgotten something else.

Well started using Fenwicks Black Streak remover and not very impressed. What am I doing wrong. They have disappeared slightly but not all gone. Am I not leaving it on long enough or not rubbing hard enough. help.

I use Fenwicks black streak remover too, seems to work with mine. I have a spray bottle that I fill ( I think 10% fluid in water) and spray that on the streaks. Leave for a minute or more, but don't let it dry, then wash as normal. I use Meguires Gold Class car shampoo.
You need to make sure the roof is clean too, the black streaks start from water on a dirty roof.

Will give it another go next time I wash the van. My roof was cleaned last year and have sorted out where to do it this year. Lucky it's not parked under trees.

I wash the roof every month or so now, previously, I did it 2 or 3 times last year and suffered from black streaks. I haven't had any this year that don't come off with a wipe of my finger.

rickandbev16 wrote:In fact while I'm on the subject, I have what appear to be streaky runs on the black plastic "bumper" at the rear of my Mezan. I tried Isopropyl and all sorts of kitchen cleaners which appeared to work, but the runs came back after about 10 mins drying time. I finally ended up with good old T Cut and plenty of elbow grease. This left the 'Van looking pretty for a couple of days........ and then it rained........
Anybody got any ideas on how to make the bumpers stay looking nice ????
Many thanks, Richard

On my last van I used black shoe polish.