Mariner

Thanks for that. A colour is required!

Yes, that's correct. It's a project largely brought about by SWMBO 😐.

I'd like to add a decorative feature, made entirely out of some new wooden "moulding" (bought from a quality timber merchants) which is 35mm wide and 10deep. It's above the deck level and should not be subject to any great wear and tear. Could anyone advise me on paints? I'd like a reasonably glossy finish at the end. I have lots of time to deal with it (though perhaps less cash 🙁). Thanks

Why did you feel the need to use the term "majority of cases" in your response? If it's not at all a gamble (even a very small gamble), that term is totally superfluous, isn't it? It seems to me that using a system is very probably ( I too can qualify every detail) more likely to achieve a really good outcome than using whatever "falls to hand". A quality company will optimise the primer and the top coat for best compatibility and be fully complementary in providing a protective coating. For critical applications, the system may consist of a number of coats. When you consider all the hard work necessary to do good preparation before painting, I really do want (and I'm willing to pay) for paint which will perform as well as possible. Strangely, a friend who is extremely fussy about only using what he considers to be premium grade (big-name / high cost) engine oil in his car told me the other day that he was painting the underside of it with some paint he bought at Lidl. That seemed like an inconsistent approach to materials procurement.

It's a gamble. In recent years, I have become firmly of the belief that primer and top coat should come from the same source; you have bought a "paint system". However, in most instances, people do get away with random combinations. As for Hammerite, 20 years ago they made really good paint, but as with many brands, they have re-formulated their paints to meet current Health and Safety regs and what sells as Hammerite now is not the same stuff and I don't use it any more. The one exception is that I do use their Special Metals Primer, which is intended for aluminium and various other non-ferrous materials; quite please with that, which seems to be a water-based paint.

Internet radio certainly opens up a vastly increased number of stations to listen to

Both FM and DAB work at VHF frequencies and so the signal strength you get depends a lot on the lie of the land between you and the transmitter. If you are in a location where there is a lot of high ground in-between you and the transmitter, that greatly reduces signal strength. In contrast, MW and LW are not much affected by such factors. What greatly helps both FM and DAB radios is the option to connect them an external aerial (these need not be too big) which would be mounted in the highest point on the boat (perhaps held in place by a quick-release clamp, so it can be taken down). There are strong advocates of both FM and DAB standards, but be aware that the BBC has repeated warned that it intends to close down the FM services as DAB becomes the established technology

I replied to Rolls; Thanks for the honesty Steve. I’m a PhD in chemistry so it fits in with everything I’ve picked up about lead acid batteries this last 40 years. When I get my boat, I’ll certainly be looking for Rolls batteries, which I’d already picked up as being highly rated in the UK. Best Wotever, are those some species of dogs in your avatar- hard to tell.

IN post 74, Wotever stated It is possible to discharge a quality deep cycle battery such as a Rolls all the way down to 0.5V and then recharge it all the way back up to 12.6V, If that recharge is performed immediately following the discharge then the battery also won’t demonstrate any significant corrosion or sulphation. On that basis, I mailed the following enquiry to Rolls; Hi, I am just about to buy marine batteries for the first time. A colleague recommended Rolls. I had always believed that discharging a battery below ~10.3 volts did some degree of permanent damage (perhaps small, but accumulative if this re-occurs). He tells me that your batteries have been shown to be able to discharge down to voltages as low as 0.5V (perhaps repeatedly?), with no adverse effect if immediately re-charged. Can you confirm which of your battery type is able to do this? This is the reply from Rolls "Yes and No... Yes in the past we've been able to do this, but every time you do some damage results. That damage is usually heating/corrosion on the plates. This damage is cumulative, and if you keep doing so it will significantly reduce the life of the battery, regardless of make or manufacture. Wish I could tell you otherwise, but I be lying to you if I did..." Regards, Steve Higgins, Technical Service Manager So Wotever the “battery expert” says no significant damage and Rolls say every time there‘s damage and it’s accumulative. As (yet) another PhD in chemistry (corrosion), that's what I expected. Godspeed Dan Eley! This is a great forum!

Fair comment, limited only by the fact that I now have to hand over my personal cash to get copies of (most) published papers in journals and that information found on the web is not edited or reviewed but is often presented in the context of trying to sell products. But it was Wotever who raised peer review papers and if someone wants to give me copies of such, I'll promise to read them! Dan Eley's use of the term "primary cell" is clearly not to everyones liking, but who wants to stand up in court and say it was wrong! IS Wotever associated with any specific battery companies... maybe Rolls?

At this stage, I will simply let others judge your "personal views" for themselves. At least for the time being!

Corrosion is an irreversible electrochemical process. That pin-head you are standing on looks very small. Regarding deep cycle, surely is refers not to discharging a battery to anywhere near zero volts but simply towards even 10.5V. Again, there is literature around that the number of cycles generally diminishes with the extend to which the battery is routinely discharged. Batteries can be optimised for different functions but the underlying chemistry is the same.

Looking for information on effects of discharging down below~ 10 Volts, I found the website of Northern Arizona Wind and Sun. They have an FAQ’s on Deep Cycle Batteries; https://www.solar-electric.com/learning-center/batteries-and-charging/deep-cycle-battery-faq.html#Battery%20Voltages In a section entitled “Why 10.5 Volts” (which I have edited, but visit it yourself) “Throughout this FAQ, we have stated that a battery is considered dead at 10.5 volts. After it gets below 10.3 v you only have 35 mins of anything useful available from the battery. The battery is now dead and most likely will not fully recover”. The keyword here is "fully". If someone has a boat and operates the batteries so that by the end of each night the batteries are below 10.5V, those batteries will show decreasing capacity and poor lifespan. I did have a look on the Rolls website to see if they suggest a minimum voltage but could not find anything there. Maybe I'll mail them.

What I said in post 66 was "This damages the battery and will reduce its performance and shorten its life". I did not say deep discharge totally destroys the battery. Before cars were fitted with lights-on alarms, I too flattened batteries on a number of occasions leaving headlights on, and then did re-charge them and continue to use them. The question is, to what degree the battery's performance/life was diminished by that action? To do that once or twice in a battery's life may not be vastly detrimental, but if it's been done on a daily basis it surely has a significant effect?

That explanation about batteries going in "primary" mode below a certain voltage was presented in a lecture, at which I was present, in a chemistry degree course at Nottingham University back around 1975, by a very eminent professor of physical chemistry, Dan Eley OBE, FRS (https://en.wikipedia.org/wiki/Dan_Eley Unfortunately, he passed away in 2015 (aged 100!) so I cannot go back to him. The subject of peer-reviewed papers has come up; if anyone finds a peer reviewed paper which claims Dan was wrong, please do share it.

My understanding of lead acid batteries is that they work in two regimes; a) discharging them down to about 10V is fine, does no damage and they are fully rechargable (i.e. it's a "Secondary cell") b) discharging them below 10V and at some point the battery is supplying power by means of an irreversible chemical action (i.e. it's working as a "Primary Cell". This damages the battery and will reduce its performance and shorten its life. For sulphated batteries, electronic pulsators have been developed which apply a high frequency (15kHz?) high voltage spikes. I admit to having being wary about these devices, but I bought one in the form of a kit from a company called Courtisetown Marine (no connections with them) and found that it had a very good effect on some old batteries. Batteries fail via a number of processes, of which sulphation is just one. My impression is that a battery which is compromised by sulphation alone, the pulsator devices can achieve a worthwhile degree of restoration.

Hi, I have never even set foot on a narrowboat but I'm curious. I am fairly handy with all kinds of mechanical and electrical things and have a garage full of tools. If anyone has a restoration job on in north Oxfordshire, I may be able to lend a hand; please PM me.

As others have shown, there is certainly at least one website where the figure of 6 is quoted, but the vast majority of other sources claiming more typical values of around 2. Of course rust composes of different forms of iron oxide, together with hydroxide, but I have spent quite some time on the web and cannot find single peer-reviewed paper, or a published referring to PB=6. My own background is in the British Nuclear Industry. As you may know, the first generation of reactors in the UK (the "Magnox") ran in to very serious problems of "anomalous oxidation" of mild steels, and very soon after they were put in to service, all of the stations had to be run with their operating temperatures turned down by about 30%, with corresponding loss of power output (seriously bad news!). The problem had never showed up in the development work done before construction, and I'm not sure if anyone ever figured out why the problem occurred in-reactor. This was a problem related to oxidation rate rather than PB.

Can you tell us the source of your information that 1mm of steel transforms in to 6mm of scale? If you look at Wiki to find out about Pilling-Bedworth ratio https://en.wikipedia.org/wiki/Pilling–Bedworth_ratio that tells you that one volume of iron produces about two volumes of oxide. Without doubt, rust tend to be very porous, and mixture of oxide and hydroxide, so in reality, 1 to 2 probably underestimates it ...but 1 to 6??? Pitting corrosion is very often the source of much grief. Pretty often, that occurs where there were minor imperfections were rolled in to the steel sheet at the mill. Not sure what you can do to avoid that in a bilge. Can sacrificial zinc anodes be used in bilges just as they are on the outside of large ocean-going vessels? I see that some narrowboat engines include sacrificial (replaceable) zinc anodes in their cooling systems.

Is it the case that although the systems are fairly simple, that the detail and the layout vary quite a lot from one boat to the other, and that on many boats, there's no record been made of how things have been set up, so you just have to unravel it for yourself? In fact, if a new owner hasn't been given an electrical plan, figuring it out and getting it on paper would be a good thing to do? M

Hi, as a newbie I wonder if I can join this discussion with some very general questions - and they might also help the OP? I am very familiar with car electrics; am I correct in guessing that boat electrics must have a lot of commonality? Perhaps someone could explain where the differences lay; perhaps a boat is more like a car & caravan. Any links to good write-ups would be great. Thanks M

Might be a good time to invest in fitting a guage? I know that, in cars, when the oil pressure light comes on, it really means that something bad has/is already happening - which is not as helpful as a gauge, which gives you a chance to pull over before something very expensive has happened.

Especially where rust is light, I tend to avoid rust "converters" but try and get as clean a surface as I can with the wire brush (on angle grinder) and then paint with zinc phosphate primer and then top coat. I really like Johnstone's products. One of the rust converters that has been around for decades is Jenolite. The original product (actually called a rust 'remover') was essentially phosphoric acid which left a layer of iron phosphate on the surface, and that seem to work well on stuff that was really badly rusted. More recently, they brought out a new product called a converter and I tried that and was very unimpressed. Ask ten different people and you will always get several different likes and dislikes when it comes to products to treat rust. The one thing that everybody might agree on is to wear a good face mask when you do the brushing; I find that rust dust up my nose really bugs me for days!

I think it is the case that when you see "Red Oxide" paint for sale now, that refers only to the colour, i.e. it is the same red colour that the old lead-based paints were. For example, Screwfix's Red Oxide is actually a really good zinc phosphate primer which is made by Johnstones, an old British company, now part of an international group. Their advice is not to paint when it's 8'C or lower. There is also a lot to be said by choosing both a primer and a top coat produced by the same company so that you really know they will be 100% compatible.