How to Store A Classic Car in Winter​

How to Store A Classic Car in Winter​

Classic cars are an investment manifested from a passion and respect for the vehicles and leaving them outside during the winter months is a one-way ticket to rust and corrosion on your pride and joy. Winter is an especially important time to be protecting these vehicles, as they definitely can’t sit outside. To establish how to store a classic car in winter, we need assess what elements cars need to be protected from, why it’s important to do so in the winter, and how all of this is possible.

What are we protecting them from?

In order to know how to protect cars over these months, we need to know what we are protecting them from. Dust and dirt are a concern all year round, and before placing your car into storage for an extended period of time, these should be considered. The real concern is brought along by the drop in temperature.

The average RH (relative humidity) levels in the UK are incredibly high- around 80%, and this a year-round figure. In colder temperatures, the air is unable to hold as much moisture as it does in the warmer temperatures. So, where does that moisture go? That water content has nowhere to go but to be deposited on to every surface that it can reach. This is why we see thin layers of condensation over almost every surface that has been kept in these colder conditions.

“This means that during the winter, your car will have a layer of moisture coating it, effectively giving it a shallow bath that lasts for the entire season.”

Moisture and materials don’t work particularly well together, as the moisture will try to permeate whichever surface it is resting on and effectively spoiling any material that is exposed to for an extended period. This is because the oxygen in the water reacts with iron and its alloys, like steel. These just happen to be very common materials in classic cars.

So, what are your options then?

There are a few best practices to follow before it comes to the actually putting the car away. A full tune-up and clean is recommended; this ensures that your car is in the best possible condition before it is left in hibernation. We wouldn’t recommend purely leaving it alone during this time, but the vehicle won’t get as much attention during the cold, winter months as it does in the summer, so it makes sense to make sure that it is in top condition before being hidden away.

Many would also recommend placing the car inside a protective ‘bubble’. The purpose of this is to stop moisture from getting onto the surfaces of the car. This is largely ineffective as it only stops dirt from getting on to the materials. It doesn’t allow you to have control of the climate in your garage and will only barely protect from moisture. At the end of the day, garages are often the most under-insulated rooms of any building and will be more susceptible to the outside conditions than any other part of your home.

From here, it is time to work out the best way to combat the humidity issues within the garage. We have explored the relationship between temperature and humidity, covering the fact that the drop in temperature will effectively release moisture from the atmosphere due to its inability to contain as much water in these conditions.

This begs the question, why not just heat the room?

If the temperature is what is causing the atmosphere to release moisture, then surely raising it will help the atmosphere retain the moisture that would otherwise be affecting the vehicle. The issue with this is that the temperature change will not affect the RH level. This 80% humidity level is calculated by ASHRAE data and is all year round figure in the UK, making it one of the most humid countries on the planet, no matter what the season. Moisture will inevitably come into contact with the car at any temperature as the humidity is unaffected by this.

There are also options to place silica gel in the same environment as the car, while this does get rid of the moisture in the environment, it is both unreliable and expensive to maintain. Getting the right amount of silica to maintain an entire room for the entire season is more of an investment than finding a system to remove moisture from the atmosphere. It also requires constant maintenance to replace the bags/gel frequently.

If we use the corrosion curve as a basis for understanding the ambient conditions at which steel begins to corrode. We can then begin to ascertain the ideal conditions at which a car should be stored for rust not to be a factor. This deterioration will begin to show signs of taking effect within about 20-30 days, so we can see just how crucial it is to protect materials like steel. At an RH level above 40%, steel will slowly begin to corrode, and from 60%, it will suffer at an exponentially higher rate, giving us our first humidity restriction to take into account, we now know the maximum RH level to maintain.

Steel is not the only material that needs to be considered when it comes to mapping out the ideal conditions to preserve a car at. There are rubber seals, leather interiors and potentially a couple of other materials that will have been used in the production of the vehicle, all of these will corrode or be affected by a build-up of mould/mildew at a different level to the last. Not only this but with a material such as leather, an RH level that is too low will cause the material to harden and crack. It loses its softness when it is too dry.

“Maintaining a relative humidity level between 30-50% is where we find the sweet spot during car storage.”It will leave all materials in optimum condition and ensure that your car will be kept in the same state that you left it, but what kind of system would make this work?

The answer: desiccant dehumidification.

Our solution is based on maintaining and controlling both relative humidity levels and airflow to remove ambient conditions from your garage and manufacture the conditions that are right for you and your vehicle, protecting it for an indefinite period. Compared to something like heating the vicinity of the car, dehumidification becomes a much more financially efficient solution as well. Heating requires to be continually running to maintain a warmer temperature, especially during those winter months- but the dehumidification units that we utilise are constantly measuring the RH levels, switching itself on and off as necessary to both maintain the perfect, constant level without constantly drawing power to condition the atmosphere.

There’s no doubt about the fact that winter weather makes it extremely difficult to store a car.

“With cold weather acting as a catalyst for corrosion in ambient conditions which are already affecting your car, a solution that actively defends against humidity over all else is required.”

Not only does it keep your car perfectly safe from these moisture levels, it also allows you to take your car out whenever you want and gives you the opportunity to go and inspect the vehicle without having to be paranoid of displacing any systems or covers that you may have spent much of the time getting into position.

As our dehumidification systems monitor the relative humidity levels inside the garage, you can also get live updates regarding the exact conditions of the room from a tablet that comes with installation. Instead of guessing as to whether or not you have created the right conditions for your car, you can see in real-time the exact RH levels and be safe in the knowledge that ambient conditions will not be having any form of negative effect on your car.

Ultimately, classic cars are an investment.

There could have been months of handiwork or a substantial monetary exchange for you to be able to enjoy a car like this. Allowing it to be left in cold, humid conditions over the winter will only make things harder when you want actually to enjoy driving it. Purely from an aesthetic perspective, preserving your car like this will ensure that the paintwork remains pristine, chrome stays shining bright, steel is in an ideal condition, and the leather remains soft. It lets your pride and joy stay as exactly that.

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