A Driving Instructor's Blog

Weather

Smearing windscreen in rainI’ve mentioned this in the smearing windscreens article, but we’re approaching that time of year where it gets wet and cold, and a lot of crap gets thrown on to your glass and builds up into a nasty film that doesn’t easily wash off.

I’m always amazed that some people only put water in their wash bottles (if they have anything in at all). I’m even more amazed that some of those using just water are ADIs – and my amazement maxes out when I hear them trying to justify it.

Water on its own does not have sufficient wetting properties to attack oil, wax, and grease. Even proper washer fluid can have problems, which is why you get that mosaic pattern left behind when you wipe in the wet. You need a good detergent to clean off oily deposits, and a small amount of alcohol to assist with wetting. Alcohol also functions as an antifreeze, so whereas using just water means you’re going to get a popsicle with the first frosts, a proper washer fluid will protect you to well below freezing.

A typical concentrated screewash that you dilute yourself is usually used at levels between 10% and 25% in water depending on the weather, and a 5L bottle costs about £5. Depending on whether you’re making a summer or winter mix, every 5L of diluted washer fluid therefore works out at between 50p and £1.25. If you use the concentrate neat – I’ll talk about that later – then obviously a batch costs the full £5.

In a bad winter, with lots of rain and slush, I will easily get through 5L of washer fluid each week. In a dry summer, I might use only a quarter of  that. Over a whole year, I would be paying around £30 for washer fluid if I made it from concentrate. It’s not really a lot of money, but it’s still an overhead.

Of course, you can buy ready-to-use washer fluid, where the dilution has already been done for you. If you find a suitable bargain, you can pick it up for between £2 and £3 for 5L, but the normal retail price is similar to that of a bottle of concentrate. It means that you’re paying between £1.50 and £5 extra for what you can essentially get out of a tap! A lot of people buy this ready-to-use stuff, but if I were to do so, it could cost me between £75 and £170 a year depending on how much I’d paid for it.

Also remember that retailers are sneaky and they put prices up in winter. At one time, for example, my local Makro was doing BOGOF on the concentrate I used to use – and it was a good price to start with. But they only did it during the summer when demand was low, and in winter the price doubled and there was no BOGOF. If you buy it, stock up when it’s cheap.

So, is it possible to make your own screen wash cheaper than this? Washer fluid needs to be able to do two things:

  • clean
  • not to freeze when it gets cold

It’s basically just a mixture of alcohol and water with a bit of detergent.

Alcohol – as ethanol – functions as an antifreeze and a wetting agent. The whole subject of freezing point depression in alcohol/water mixtures is a huge topic in physical chemistry, but the bottom line is that pure water freezes at 0°C, whereas adding different amounts of alcohol lowers the freezing point. A 10% ethanol/water mixture freezes at -4°C, a 20% mixture freezes at -9°C, and a 30% mixture freezes at -15°C. A typical commercial concentrate (£5 for 5L) which claims it freezes at -6°C when used neat must therefore contain 15% alcohol.

Alcohol is the most expensive ingredient in screenwash, and a 15% solution will have 750mls of ethanol in a 5L bottle of concentrate. Ethanol can be purchased for around £2 per litre, so a 15% concentrate will contain about £1.50 worth.

Whatever detergent you use has to be relatively non-foaming – you don’t want bubbles blowing down the street when you use it – and it has to be the kind that is actually going to attack the crud that get on your windscreen. This is another big chemistry subject, but to cut a long story short, Traffic Film Remover (TFR) is ideal. TFR gets anything off your car – tar, oil, mud, insects, bird crap, dead squirrels, that sort of thing. I get mine from JennyChem, and it costs £12.50 for 5L. However, you only need to use it at a concentration of between 1% and 2%, so 5L will go a long way – you need about 15p to 30p worth of TFR in your DIY concentrate. One 5L bottle of TFR will make up to 70 batches.

A batch of DIY concentrate will therefore cost around £1.70 versus £5 for commercial brands. Each batch of diluted washer fluid will cost you between 17p and 45p.

What if the temperature goes below -6°C?

When we had those two cold winters some years back, the first one caught me out, and my washer fluid froze – even though I’d followed the directions on the concentrate bottle. I’m a chemist, so the solution was simple: I nipped into a hardware store and bought a small bottle of methylated spirit, and poured that in. After half an hour or so, my wash bottle was defrosted. That was when I got the idea of making my own washer fluid – I would always know what temperature it was good down to.

So, the answer is to increase the amount of alcohol in your mix. Even using your DIY mix neat is going to be a lot cheaper than buying a low-temperature version – the price is proportional to the amount of alcohol in them. But for even lower temperatures, increase the alcohol to 20% or 25% in the concentrate and use it neat. It’s still cheaper than buying it.

How can I prepare for cold temperatures?

You just have to use common sense. In summer, using concentrated screenwash neat is just a waste of money, so it makes sense to use it at the 10% dilution (negligible antifreeze properties). When it gets colder, a 25% dilution will be good to about -2°C. If it gets very cold, use the “concentrate” neat to protect down to -6°C. If it gets really cold – below -8°C or so – add extra ethanol to the neat concentrate. An extra 500mls (£1 worth) will protect down to about -12°C.

Can I make it with more alcohol in it?

Yes, but be careful. Ethanol is flammable, and on its own has a flash point of 14°C (that means that at that temperature and above, a combustible vapour exists that can easily be ignited). A 10% solution in water has a flash point of 49°C, which is much safer. A 20% solution has a flash point of 36°C, which is still safe unless you store it in a very hot place. A 30% solution has a flash point of 29°C, and this is quite likely to be encountered in hot weather. My advice is not to exceed about 25% of ethanol.

If you make up the DIY concentrate using 1L of ethanol instead of 750mls, it’ll be good down to  -9°C. In fact, I am fairly certain that the brand I used to use was once safe down to that temperature, but somewhere between 2010 and the present it started referring to -6°C as the lower limit. I suspect they reformulated to cut costs, and dropped the alcohol content from 20% to 15%.

Don’t store a strong winter mix in your car during the summer. And definitely don’t carry any neat ethanol during the summer months, and only the smallest amount in winter in case you have to do an emergency defrost like I did that one time.

It seems complicated making your own

That’s why there is a market for ready-to-use screenwash. It’s up to you.

What kind of water do you use?

Tap water will work for most people. It’s probably what they use when they’re diluting commercial concentrate. However, tap water contains dissolved minerals – especially in hard water areas – and it leaves white streaks when it dries. It’s best if you use distilled or deionised water. Distilled/deionised water doesn’t do that. The only problem is that unless you already have access to it – and you might – buying such water is relatively expensive (50p per litre), and would add £2 to the cost of your DIY concentrate.

Personally, I used either rainwater (boiled) or the condensate from a dehumidifier we have to inhibit condensation and mould growth. If you store this source of water, make sure you store it with the alcohol already added, as that inhibits the growth of algae.

I just use water

Water on its own is no good. If the temperature falls, it WILL freeze. Even if it doesn’t freeze in your main washer bottle, it will in the pipes and at the nozzles. Water alone also doesn’t clean many things off the glass – it won’t touch oil, grease, or squashed insects, and it will struggle with tree sap.

If you do get a freeze up, trying to use the pump might cause it to burn out. Although I haven’t come across the problem recently, it can also cause pipes to burst or become detached from the main bottle (many years ago, that was a regular occurrence on a Citroen Xantia I used to have).

And remember that if you are driving without the ability to keep your windscreen clear, you are committing an offence. The Road Vehicles (Construction and Use) Regulations 1986 says:

Every wiper and washer fitted in accordance with this regulation shall at all times while a vehicle is being used on a road be maintained in efficient working order and be properly adjusted.

Arguably, you are not complying with this if you just use water. If it freezes (or the bottle is empty) and you drive, you’re definitely not complying with it. It is shocking that some ADIs are apparently doing this.

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UK Mean Monthly Temperature - 2017It seems to have escaped everyone’s attention yet again, but if we draw a horizontal line on a graph of temperature versus time of the year at, say, 10ºC, there is a tendency for the actual temperature to be below 10ºC in winter and above 10ºC in summer. It’s funny, I know. But as far back as I can remember, that’s the way it’s always been.

In 2017, for example, the mean UK temperature for each month is shown in the graph above. Notice how spring and summer was warmer than autumn and winter.

Let’s add 2018’s data so far to this graph.

UK Mean Monthly Temperature - 2017/18The only anomaly – if you can call it that, since February and March were a lot colder than last year – is July. Nevertheless, this is sufficient for the amateurs who go under the title of “reporters” for rags like the Daily Mail and The Sun to get their rulers out, draw a line through May, June, and July, and start predicting that we’re all going to die because by October it’ll be above 60ºC. Of course, come September, they’ll be predicting the usual Ice Age accompanying “the coldest winter on record” (and that’s an actual quote from at least one of those two comics over each of the last three or four years).

Yes, it’s been hot. But it’s not like we haven’t had hot spells before. Just like when it’s cold, it isn’t like we haven’t had cold spells before, either. And it goes up and down throughout the year as we pass through the seasons. Furthermore, even though it has been hot, this year’s “hot” has been quite pleasant most of the time (and I hate hot weather) since it hasn’t been accompanied by the usual humidity we tend to get in the UK.

Here’s the same chart with 1976 added to it.

UK Mean Monthly Temperature - 1976 addedFair enough, this July was about 1 degree hotter, but other than that there’s nothing much different. Christ, I was in a maths lesson at school in June in ‘76 and it snowed on the 14th (or was it the 12th… whatever), and it’s not done that since!

When you look through the data from 1910 until the present, July had the same mean temperature recorded for 1983. It was slightly hotter in 2006, and almost as hot in 2013. Other years have simply fallen within the range.

There’s no question that average temperatures have risen over the last hundred years or so – especially since the 1950s – but that doesn’t mean that any new high or low is a sign of Armageddon. Most of it comes down to the Jet Stream. The last few years, it’s spent summer down by the equator, flinging low pressure system after low pressure system at the UK. This year, it’s vacationing somewhere up near Iceland, and fairly consistent high pressure is pulling air up from Europe. It happens.

Sometimes, I’m embarrassed to be British. We moan when it’s hot, we moan when it’s cold. We moan when it’s wet, and we moan when it’s dry. We moan if it’s a crap summer, and we moan if it’s not. For f*$k’s sake, get a life, people. It’s been one of those “glorious” summers just over 50% of the twats out there voted to go back to in 2016. Enjoy it – you might not be able to afford the next one.

Just remember. In a couple of months it’ll be bloody cold again. And probably wet – just like it was before it got hot this year.

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Silver Birch - summer 2017My article about early leaf drop in Silver Birch trees is very popular – but it has really peaked this year (2018).

My own trees started going yellow this time around in mid-June. After a lot of research, I concluded that it was due to heat stress as a result of the prolonged warm weather and low rainfall we have experienced. I know that some places have had torrential downpours, but it isn’t enough. The temperature has remained pretty much in double digits the whole time, and has been in the mid-20s and low-30s most days for almost two solid months, and with no end in sight.

I commenced deep watering right after I found it as a remedy in June, and it has worked like magic. Right now, I simply set the sprinkler going for about an hour in each of three separate locations, and I do this each night (next year, I’m going to install deep-watering spikes to help the water get deeper into the soil). I have also found a way of watering and fertilizing at the same time.

When trees are stressed as a result of high humidity and low rainfall, they can’t get enough water and begin to shut down just as they do in the Autumn. It doesn’t kill them unless it happens year after a year, but obviously you can take steps to deal with it once you notice it.

My Silver Birch in 2017One thing I have noticed with the benefit of hindsight is that the foliage on virtually every Silver Birch I have seen this year is thinner than in previous years (that’s also true for a lot of other trees I’ve seen). The leaves are actually smaller. The reason I say “hindsight” is that about a month into deep-watering and my tree has put out some significant new growth and the leaves on that new growth are much larger, and just like the photo I took last year.

Note that we have no hosepipe ban, and I wouldn’t be doing this if we did.

Once I commenced the watering, the yellowed leaves all fell over the next week or so, but no more were produced. Right now, not a single leaf has fallen in the last month at least and the whole tree is green with the aforementioned new growth. It is also producing fat catkins.

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The Access Irrigation Fertlizer DilutorLet me introduce you to my new toy – the Access Irrigation Static Dilutor.

One of the most popular posts on the blog is the one about Silver Birch Trees shedding leaves in the middle of summer as a result of nutrient deficiency in the soil. The remedy involves applying fertilizer and watering it in so the trees can get at it.

In 2018, though, another cause of premature yellowing has surfaced. The prolonged hot weather has stressed many trees, and the remedy for that is deep watering.

Ever since I found the solution to the nutrient problem I had toyed with the idea of semi-automating the fertilizer/watering process by combining the two and applying it via a sprinkler system. Indeed, I toyed to the extent that I bought a cheap Venturi mixer – which should have worked, but didn’t. I concluded that my water pressure was not sufficient to provide the necessary lift in the Venturi, because I just couldn’t get it to suck anything up. So I gave up on the idea for a year or two until 2018, when watering became such an issue in its own right.

I started Googling and many things came up, but they were all on a small scale – watering plants in greenhouses or by drip-feeders. But there was an American dilutor which apparently did exactly what I was after. You put your fertilizer in the mixer container, connected it to a tap, connected the other side to a hosepipe, and let it do the mixing before sending it down to your sprinkler or spray nozzle. The problem was availability in the UK. It came in various sizes, and the only one carried by any UK-based seller had a capacity of one pint (damned American units), which is no bloody use at all except for window boxes or greenhouses. The next size up was only available from American suppliers, so apart from the $100+ price tag, there was also the $100+ shipping fee – not to mention whatever UK Customs & Excise (who have become very sharp of late) slapped on it when it came into the country.

I was just steeling myself to order the American product, but while I was searching for the best price I accidentally came across the Access Irrigation Static Dilutor. It hadn’t come up on any of my previous searches over the last three years, and even when it did this time it hardly stood out until I followed the link and read the specification sheet and user manual. As an aside, whoever designed the Access Irrigation website decided to use images of text for product titles instead of just plain old searchable text. As a result, Google isn’t indexing them and normal search terms like  “inline fertilizer dispenser” or “fertilizer dispenser using sprinkler” don’t stand a chance.

Access Irrigation were very helpful with my pre-order questions, so I went ahead an ordered it. It came next day.

Gardena ZoomMaxx SprinklerI’ve also recently bought a new sprinkler – a Gardena ZoomMaxx. Depending on water pressure it can water over a range of between 3m and 18m, or an area between 9m² and 216m² in an almost circular pattern (though the pattern is adjustable). In my case, with a water flow rate of 7L per minute (which is classed as “low pressure”), it was able to cover an area of around 80-90m² – which is about 5 times what my old bar sprinkler could manage.

The Access Dilutor consists of a thick plastic bottle which can hold about 9L of liquid. A screw-fit head assembly consists of a Venturi unit with a choice of Hozelock or GEKA fittings (Hozelock fitted as standard, but both types supplied).

For anyone who is interested, a Venturi is so-called because of the Venturi Effect. This is where a fluid flowing through a constriction in a tube creates a pressure drop, and this can be used for various effects. I became familiar with it when I was still at school, because we used small Venturi devices connected to laboratory taps to produce a partial vacuum when filtering liquids using conical flasks. In the case of the Dilutor, water flowing from your tap goes via the Venturi and down to the sprinkler head, and the pressure drop created inside the Venturi is used to pull liquid fertilizer from the bottle and into the main water flow. There is a bit more to the device than that, though, because as the fertilizer is removed, it is replaced by clean water to keep the bottle completely full. Since the fertilizer solution is more dense than water, this clean water sits on top, so you have a distinct border between fertilizer and water. Access Irrigation says you should use food dye if your fertilizer is colourless so that you can see when it is all used up. In my case, my mixture contains chelated iron, so it is almost black. Incidentally, this is why they call it the “static” dilutor, because you mustn’t move it when you’re using it, otherwise the divided liquids get all mixed up.

Until I tried it I was sceptical, but it really does work. The Dilutor is supplied with a range of nozzles which fit on the end of the dip-tube that carries the fertilizer. This allows you to control how quickly the fertilizer is used up. In my case, since I wanted to irrigate for an hour at each of several locations, and since my water flow was 7L/min – or 420L/hour – I used the light blue nozzle corresponding to this volume of water (edit: I have since changed to the grey nozzle, which uses the fertiliser more quickly, my logic being that I want to get the fertiliser on the lawn, then make sure it is watered in properly). I was doing my first run in the dark – literally – and using a torch the border between the black solution and clean water was dramatic. It was all used up in slightly more than one hour.

Previously, and as I have pointed out in my article about summer leaf drop, I was dissolving solid ericaceous fertilizer in water (which takes a couple of hours), and using this as a concentrate in five watering cans-full each liberally spread over 10-20m² (about half an hour overall), then watered in using a bar sprinkler for about half an hour in each of five locations to get the coverage. Overall, it was maybe 8 hours involving frequent interventions by me.

Now, using a liquid version of the same ericaceous fertilizer, I can make up a full batch in the Dilutor in about three minutes, and just set the sprinkler running for an hour. Then, I make another batch, move the sprinkler, and repeat. It only takes a couple of hours now to get the same coverage – and I’m doing a lot more irrigation because of the heat stress problem this year.

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Cartoon cars, head-on crashA couple of days ago, I updated my article on Driving Tests and Lesson in Snow after someone found the blog due to their instructor claiming he wasn’t covered to drive in icy conditions.

Cancelling lessons because it is dangerous is fine, but I am not aware of any insurance policy which would preclude driving. I didn’t think much of it after I’d updated the article – but then I came across this story. It seems that some moron on Twitter started the rumour, and other morons have picked it up and run with it.

Police and insurers have assured people that insurance is valid even in the worst weather conditions. Obviously, the same rules apply in bad weather as they do in good weather. Namely, if you drive like a twat and have an accident, your insurance may be affected.

It is possible that the original reader’s instructor had also seen this story and been suckered by it.

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Giant KittenOr, what the media insists on referring to as “The Beast from the East”.

It’s a bit nippy, though not dramatically so, and there are frequent light snow flurries. Every hour or three there is a heavy flurry, which settles – then melts almost completely as soon as the sun comes out. And this is speaking from an “Amber Warning” area of the UK.

The BBC has reporters standing in bright sunshine with no visible lying snow, trying desperately to explain why a form of transport from Victorian times – and one which the government is trying to invest in “for the future” – has to cancel trains en masse.

Needless aerial footage of the “chaos” from “disaster areas” shows snow depths barely covering the grass. Weather maps are all being carefully crafted to make sure it looks like London is in one of the “disaster areas”. Evidence for the “disaster” amounts to a drone shot of some bloke walking quite easily across a snowy field.

Some prats have crashed during rush hour because they were driving too fast. Roads are being described as “treacherous” by Police, as if they have never been so before following previous (and much heavier) snowfalls.

Schools are closing when there isn’t enough snow to build even a passable British Snowman. And KFC is still operating a “restricted menu”, so the little darlings will have to go somewhere else.

What a bunch of wusses we have become in this country.

For me, the biggest annoyance is the rapid build up of 1cm of crap on my windows and headlights every time I start driving. Closely followed by irritation at the twats who are overtaking me and cutting in.

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Glacier - an ice age comethThe Sun is at it again. I saw a small item in today’s paper copy reporting that it will be -15°C by the end of the week, and that it will stay like this until the end of March. Oddly, the front page of the online version’s UK news has a story about how plants are blooming a month early, since spring is on the way.

I’m not sure quite what it is they’re trying to get at, since this winter has not been uncharacteristically cold, mild, wet, or dry. It’s been a bit of all those things, just like British winters tend to be.

It’s worth noting that the Met Office isn’t forecasting anything like what The Sun is. Neither is Netweather.


And this is why I wanted in on the ground floor! All The Sun’s blather about snow over the last fortnight came to nothing. Even places which had any barely saw more than a centimetre (for Brexiters, that’s about three eighths of an inch). And as for it being colder than on the dark side of the moon until the end of March, today the temperature ranged from lows of around 7°C to highs of 10°C, and the forecast – the proper forecast from the Met Office and not some two-bit amateur outfit using seaweed and pine cones – is for temperatures as high as 12°C into the middle of next week.

Fair enough, we have had quite a bit of rain today which, after all, is only unfrozen snow, but still not quite the new Ice Age that The Sun was assuring us was underway.

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The Met Office has revealed the names it will be assigning to storms during 2017/18. Here they are:Storm Names 2017/18 - Met Office

You could just leave it at that. If you’re like me, though, you might see something a little more sinister.

Once upon a time, hurricanes were always given female names. In our modern PC world, though, this is totally unacceptable, and nowadays they use a mixture of male and female names. I believe that they alternate – so one hurricane will be female, the next male, the next female, and so on.

The Met Office – which started naming “storms” in the UK last year – has been giving them both male and female names from the start. As you know, all science in the UK simply has to involve children (and people with the kinds of children), which explains why you get names like Oisin and Wilbert.

I mean, there have been about six people named Wilbert in the last 100 years. Most of them are dead (a bit like the name, really), and those who aren’t nearly are. And although Oisin is apparently a top choice for Irish language boys’ names in Ireland, I can honestly say that the only time I’ve ever come across it is in ancient Irish literature (Oisin was the son of Fionn MacCool) through one of my favourite bands, Horslips.

The sinister part to my mind is that there are 11 male names and only 10 female ones. Can you imagine the uproar and demands for resignations that would follow if it was the other way around? And I reckon it’s only a matter of time before they start naming them retrospectively – or renaming them after the event – so that damaging ones don’t go down in history as having female names.

I’d bet money that someone somewhere has already raised that one in a meeting.

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The BBC website is full of stories today about how poor Londoners and Home Counties residents had some heavy thunderstorms yesterday. Apparently, “one month’s worth of rain fell on London is less than 24 hours.” A prominent table shows how Reading had 20mm of rain, Hampton 41mm, and Farnborough 46mm.

Mmmm. Just in case they missed it, Nottingham had a recorded total of 55mm of rain over three days between 14-16 June (20mm was recorded on 15 June). There is only one Met Office station up here, at Watnall, and the heaviest localised rainfall was definitely not there, and actual rainfall at such locations was certainly much higher. Many homes and businesses were flooded. But that never got into the news headlines. And all this applied to areas of Leicestershire, Derbyshire, and South Yorkshire.

There are a couple of dozen Met Office stations in and around London – or what is considered to be “London” when the media is reporting things. The rainfall figures from yesterday are much less likely to have missed any extreme localised events.

As the title says, all that matters is London. No one else exists on the front pages.

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They’ve been naming hurricanes (all right, cyclones) for years. They all used to have female names, but someone somewhere decided that this was sexist and now they alternate between male and female. Apparently, they have six lists for the North Atlantic, each list comprising names beginning with the letters A-W, but excluding Q and U. Usually, they only have to use about half of the names each year.Heavy rain

Britain has decided to get in on the act and has begun naming our storms, but in true British style they opened it up to the public – no doubt with prizes being awarded to the best papier mâché models, covered in glitter and dried spaghetti. As a result, possible names include: Clodagh, Frank, Gertrude, Desmond, Henry, Imogen, Jake, Katie, Eva, Lawrence, Mary, Nigel, Orla, Phil, Rhonda, Steve, Tegan, Vernon and Wendy. We’ve already had Barney, Eva, and Abigail, while Frank recently strutted his stuff. You just KNOW that the names relate to relatives and children of typical Daily Mail readers.

Laughably, virtually every storm cloud that comes across bringing rain or wind is getting named at the moment. At this rate we’re going to need another twenty names before the end of the winter.

(Obviously, this does not detract from the problems those whose homes were flooded are having to cope with).

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