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Can You Wash A Car In Direct Sunlight?
It's one of the most common questions in detailing, especially during the summer months.
The short answer?
Yes, you can wash a car in direct sunlight.
The better answer?
You probably shouldn't if you can avoid it.
Washing a vehicle in direct sun isn't going to instantly damage your paintwork, but it does make the entire process significantly harder and increases the chances of things going wrong.
Heat is the enemy.
When your paintwork is hot to the touch, every product you use has less time to do its job before it begins to dry.
This can lead to:
- Water spotting.
- Shampoo drying on the surface.
- Streaking and smearing.
- Quick detailers flashing off too quickly.
- Glass cleaner becoming difficult to buff.
- Protection products curing unevenly.
- Increased risk of wash marring from wiping a dry panel.
Dark coloured vehicles are particularly bad for this. Black paint on a hot summer's day can become almost untouchable, making what should be an enjoyable wash a frustrating experience.
If you've ever washed a car in the sun and returned 10 minutes later to find white marks everywhere, you've experienced water spotting.
As water evaporates, minerals are left behind on the surface. Leave them long enough and they can become difficult to remove, sometimes requiring machine polishing to fully rectify.
The hotter the panel, the quicker this happens.
Simple.
Professional detailers need to eat.
Cars don't stop arriving because it's sunny.
Most professional detailers work to a schedule and have customers booked in weeks or months in advance. If they cancelled every time the sun came out in the UK, they'd never get anything done. That said, professionals will almost always try to find a shaded area if possible:
- Under a canopy.
- Beside a workshop.
- In a covered unit.
- Under trees (where appropriate).
- On the shaded side of a building.
You'll also notice many professional detailers work in two-man teams or have an assistant.
One person may be washing while the other is drying and following behind, dramatically reducing the time water sits on the surface. It's still not ideal, but it's manageable when you're equipped, experienced and working efficiently.
If washing in the sun is unavoidable, there are a few things you can do to make life easier:
1. Work Panel By Panel
Don't wash the entire vehicle at once. Wash, rinse and dry one section before moving onto the next.
2. Keep The Vehicle Wet
If you're taking a break or moving around the car, lightly rinse the panels to stop products drying out.
3. Start Early Or Later In The Day
Early mornings and evenings are your friend during summer. Even dropping the ambient temperature by a few degrees can make a massive difference.
4. Use Plenty Of Water
Keep your rinse bucket full and don't be afraid to flood panels before drying.
5. Dry Immediately
Don't leave the car to "air dry." A quality drying towel should be one of the first things you reach for once the final rinse is complete.
6. Feel The Paint
If the paint is too hot to comfortably leave your hand on for a few seconds, it's probably too hot to wash. Wait until it cools down if possible.
Can you wash a car in direct sunlight?
Absolutely.
Should you?
Not unless you have to.
Even professional detailers will tell you that shade is always preferable. Washing in cooler conditions gives products time to work properly, reduces the chance of water spots and generally makes the entire process far more enjoyable.
If you find yourself caught out on a sunny day, work quickly, stay organised and tackle the vehicle one section at a time. Your future self—and your paintwork—will thank you for it.
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