Removing Black Marks on Sealant

[andyelbac]

Just gave the MH only it's second spring wash and found that these marks, where the sealant seals the joint between cab and GRP roofline, can't be got rid of. I tried Silky cream but to no avail. Any ideas and also, how the hell do I reach the bits in the middle?

 

[Sasbo]

Caustic TFR used neat applied with a detailing brush. Apply, agitate well and leave for 5 minutes then rinse well with hosepipe. It may take a couple of applications to get sealant back to white.

TFR Ultra Special

TFR Ultra Special is our strongest caustic TFR. This highly concentrated Traffic Film Remover can be adapted to a multitude of cleaning tasks including removing traffic film, oil and grease from vehicle exteriors. Ideal for high volume use where the price needs to be matched with performance...

www.jennychem.com

 

[IRHP]

Mould Magic works well but I think it's just bleach in a gel form. Stand on the top of the front wheel to reach the middle.

 

[Jez1966]

That's cool - where did you get it?

White vinegar on bathroom mold has worked for me.
You can buy 100% acetic acid (vinegar) and dilute as required.

Quick search, links are Oz/USA Thule 232 Step Up and not available.
I like that is has straps not rigid poles, would expect it to be lighter then others listed.

Multi functional option.

 

[stuartholmes]

Patio Magic does indeed look like magic & I'm tempted to slap some on the roof of my Fiat PVC but I'm a bit scared it might eat through the paint - which I've already discovered is not good in a fight with a pressure washer.

Anyone got experience to reassure me with?

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[M-J]

Patio Magic does indeed look like magic & I'm tempted to slap some on the roof of my Fiat PVC but I'm a bit scared it might eat through the paint - which I've already discovered is not good in a fight with a pressure washer.

Anyone got experience to reassure me with?

I did the roof on my old MH with Spray & Leave no issues and good results but think that was GRP rather than paint. Used on many surfaces including garage doors which are spray finished with paint similar to that used on vehicles.

 

[Revolvor]

Ouch!
View attachment 889368

That's for 4 x 5 litres, isn't it?

 

[BouncyBoatFolk]

Patio Magic does indeed look like magic & I'm tempted to slap some on the roof of my Fiat PVC but I'm a bit scared it might eat through the paint - which I've already discovered is not good in a fight with a pressure washer.

Anyone got experience to reassure me with?

I used to use it on industrial warehouse roofs, specifically the vision panels, but I noted it never gave any problem with the water based pigmentation paint surrounding where I had sprayed it.
Mike.

 

[VXman]

Had similar on my last MH, a friend of mine that used to be a valeter including the contract for a local caravan/mh sales company swore by tfr, apply with a cloth to just the mastic and then wipe off. It worked a treat.

Stand on the front wheel to reach the middle at a stretch.

Sorry, what is tfr?

 

[pagey]

Sorry, what is tfr?

Traffic film remover

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[BouncyBoatFolk]

Sorry, what is tfr?

Traffic Film Remover.Now don't let that rest on the paintwork to long. I think was originally curtain side cleaner/truck wash.
Mike.

 

[Shipps]

This worked wonders in the shower silicone and sealant so should be OK on your Van

https://www.amazon.co.uk/gp/product/B01CRBEUVO/?tag=mhf04-21

 

[Ingwe]

Cillit Bang Black Mould remover. Comparatively cheap. And works.

 

[pagey]

i think not all silicon is the same none of the above ever worked on mine the only thing that did was rolled up kitchen roll soaked in thick bleach and pushed onto the silicon i said above for 2 hours but i left mine all night ps dont get tfr on your decals

 

[tonysuvla]

We also have black marks on the white sealant and am going to try Cillit black mould remover when I get home. Works a treat in the bathroom at home.

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[stuartholmes]

i think not all silicon is the same none of the above ever worked on mine the only thing that did was rolled up kitchen roll soaked in thick bleach and pushed onto the silicon i said above for 2 hours but i left mine all night ps dont get tfr on your decals

Can't say I've tried 'all the above' on black mould on silicone sealant but did try loads & round the bath I evenually did exactly what you describe except using rolled up toilet paper pushed well into place with a credit card & like you left overnight. Totally amazed with the result being complete solution.
(Not bleach solution, keep that neat! )

 

[David and Sally]

Does neat bleach affect plastics or the paintwork?
I used some mould remover yesterday which did an ok job but I was nervous about leaving it too long in case of damage.

 

[pagey]

Can't say I've tried 'all the above' on black mould on silicone sealant but did try loads & round the bath I evenually did exactly what you describe except using rolled up toilet paper pushed well into place with a credit card & like you left overnight. Totally amazed with the result being complete solution.
(Not bleach solution, keep that neat! )

works well i use a stick to push it above the windscreen

 

[scotzsue]

I can reach the middle of the top of our windscreen with my wheel step.

View attachment 889355

Well i could maybe reach the top of the windscreen with that sorry can't help with the cleaner stuff, maybe we should all have black sealant

 

[stuartholmes]

Does neat bleach affect plastics or the paintwork?

I'd have guessed not but apparently I'd be wrong!
The AI says:
Neat bleach (undiluted bleach) can potentially damage or degrade certain types of plastics. Plastics that are particularly vulnerable to damage from bleach include:

1. Acrylic (Plexiglas): Bleach can cause clouding, cracking, or discoloration on acrylic surfaces.
2. Polycarbonate (Lexan): Bleach may cause yellowing, crazing (fine cracks), or weakening of polycarbonate plastics.
3. Polyvinyl Chloride (PVC): While PVC is more resistant to bleach than some other plastics, prolonged exposure can lead to discoloration or surface damage.
4. Styrene (Polystyrene): Bleach can cause stress cracking or dissolution of styrene-based plastics.

It's always best to avoid using neat bleach on plastics and instead dilute it with water according to the manufacturer's instructions. If cleaning plastic surfaces with bleach is necessary, perform a spot test on a small, inconspicuous area first to check for any adverse reactions. Additionally, rinse the surface thoroughly with water after cleaning to remove any residual bleach.

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[pagey]

ive been using it about 5 years now no sign of problems yet but as i said above not all silicon is the same

 

[Burge]

I've gone over mine with White Mastic

 

[BouncyBoatFolk]

I've gone over mine with White Mastic

Mastic can be usually reluctant to stick on old mastic, but fingers crossed for you.
Mike.

 

[Purrfecttune]

Based on another thread I bought Jennychem Concerntrated Motorhome and Caravan cleaner. (They are based near me in Kent).
Was amazed how effortlessly it removed all black marks, especially on the soft joins.

www.motorhomefun.co.uk/forum/threads/jenny-chem-motor-home-caravan-cleaner.298480/

 

[Burge]

Mastic can be usually reluctant to stick on old mastic, but fingers crossed for you.
Mike.

Use the Proper Stuff...... mine has stuck ,been on 7 mths Sikaflex 522