Three things happen to almost every caravan on the Gold Coast, and owners notice them in the same order. First the caravan black streaks running down the walls. Then the front cap goes dull and, one day, a hand run down it comes away white. Then the mould — grey-green spots in the shaded lower panels and along the awning. Here’s what each one actually is, what you can safely do yourself, and where the line is between a clean-up and a repair.
Caravan black streaks: where they come from
The dark runs down a van’s walls aren’t dirt. They’re oxidised gel coat, road grime and rubber and sealant residue, carried down the wall by rain from wherever water collects and drips: the awning rail, the roof edge, window frames, the air-conditioner housing, any seam or rivet line. That’s why they come back in the same places — and why washing them makes them worse. Ordinary car wash on a chalking surface moves the oxidised film around, and a sponge spreads the streak into a wider grey smear.
What works: a product made for the job, on a surface that’s been decontaminated first, worked in small areas before it dries. Streak removers are strong and will dull decals, so keep them off the vinyl.
What fixes it properly: dealing with the cause. A van that streaks badly is a van with oxidised gel coat and tired sealant. Once the surface is corrected and protected, rain runs off instead of carrying residue down it — that’s the caravan paint protection conversation rather than the detailing one.
Chalky gel coat: the three grades of caravan oxidation
Gel coat is the coloured resin layer on moulded fibreglass — the front and rear caps on most vans. Under Australian UV it oxidises into a dull, powdery layer that thickens the longer it’s left. How far it’s gone decides what fixes it:
- Mild — gloss gone, colour intact. Polishes back by hand.
- Moderate — visibly chalky, a hand comes away white. Needs a machine to cut the oxidised layer back.
- Severe — heavy chalking, uneven colour, a rough surface. Needs careful wet sanding first, and wet sanding gel coat is a one-way street: what’s sanded off doesn’t come back.
A detail handles mild oxidation and cleans the loose chalk off moderate. Anything past that is caravan oxidation removal by correction, and the decision about how far to cut is one to make with someone who’ll tell you where the line is before the machine comes out. The roof is always worse than the walls — it takes more UV than every other surface combined and nobody looks at it. If the walls are moderate, assume the roof is severe until it’s inspected.
Mould, mildew and the shaded side
Gold Coast humidity grows mould on anything that stays damp and shaded: the lower walls away from the sun, the underside and fabric of the awning, around window seals, and in the texture of composite panels. Mould on gel coat and cladding cleans off — it’s a surface problem. Mould in awning fabric is harder and sometimes doesn’t fully lift. Mould inside a seal line is a warning about the seal, not a cleaning job.
Prevention is mostly airflow and dryness. A van under a cover that traps moisture, or parked hard against a fence on its shaded side, grows more mould than one with air moving around it. Going into storage: a proper clean first, then a breathable cover, not a tarp.
Decals, sealant and seams
Anything with a pad and a compound goes around printed vinyl decals, not over them — faded vinyl is the first thing a machine polisher destroys. Sealant around roof vents, hatches, the air-conditioner and the awning rail cracks under UV, and when it does the problem stops being cosmetic: water gets into the wall, and a good finish should never be sealed over a leaking roof. Near the coast, salt air starts corrosion along seams and rivet lines on clad vans — white bloom or dark staining along the line — which is one more reason not to let road film and salt sit between trips.
Do it yourself, or hand it over
Yourself: rinse after trips and before storage; a proper two-bucket wash; streak remover on small areas, tested somewhere inconspicuous; keep the van dry and ventilated in storage.
Hand it over when the gel coat is chalking, when black streaks return within weeks of cleaning, when the roof hasn’t been looked at in a year, or when the van is about to go into storage or onto the market. Our caravan detailing guide covers what a full van detail involves; for oxidation a detail won’t fix, the caravan and motorhome coating page is the next step.
Frequently asked questions
Will black streak remover damage my caravan’s decals?
It can dull or lift them if it’s left on. Keep it off vinyl, work small areas, rinse straight away.
Can a chalky caravan front cap be saved?
Almost always, but how depends on the grade: mild polishes back, moderate needs machine work, severe needs wet sanding, which removes gel coat permanently. An inspection tells you which before anything is cut.
Is a ceramic coating the answer to black streaks?
The closest thing to one. A corrected, coated surface sheds rain instead of holding the residue that becomes streaks. It doesn’t fix cracked sealant — that’s a separate repair.
Bring us the van
Tell us what you’ve got, how old it is, where it’s stored and what you’re seeing — streaks, chalk, mould — and we’ll tell you honestly whether it’s a clean-up, a correction or a coating, and what each would cost for your van. All van work is done at our Ashmore workshop, so book a time and bring it in.
Call 0478 920 170 or request a free, no-obligation quote online.