Dr Bob
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Posts posted by Dr Bob
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17 hours ago, rusty69 said:
There is also the chemco product that one forum member favoured for wet tolerance, think it was Epochem RA 500m or summit.
Yo Dr Bobs in da house. Happy new year @Dr Bob
Happy new year to Mrs Rusty and yourself!! Hope your keeping afloat. How's life on here? Not been back here for ages!
16 hours ago, Peugeot 106 said:Seems Dr Bob you are saying dry is best
Dry is best? No. This boat's never been dry. Always lot of beer and wine available.
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On 15/01/2024 at 09:07, Peugeot 106 said:
I used Danboline in the engine hole and it is fine on the sides but the floor has started to rust. I’m going to investigate these damp tolerant epoxies for next time they sound like a wonder product. I’ve tried underwater setting repair epoxy putty before on a yacht without much success 20 years ago but times have obviously moved on. Wessex and SP epoxy ( I’ve used gallons ) are very temperature and moisture sensitive or they don’t set so this is a new one on me. Maybe it’s a derivative of the old underwater setting repair putty?
On 15/01/2024 at 10:08, BEngo said:I dont know much about the chemistry of epoxies, but there are a range of them, si taking to a specialist is a good idea. @Dr Bob is quite well up on these things and has provided good advice in the past.
"......times have obviously moved on..." er No. Sticking paint, sealant or adhesive to wet steel has always been a problem and likely always will be. There has been no step change in getting better adhesion to damp or wet steel. Marginal improvements, yes. If a major change had occurred then it would be able to be used on all coatings and adhesives and change the whole of the industrial coatings market. That clearly hasnt happened. Typically only 10% of the cost of an industrial paint job is for the coating. 50%+ is for the surface preparation. It is the holy grail of the industry (well the guys who sell the coatings anyway) to make a step reduction in surface prep costs. Applying paint to damp steel will always be a compromise.
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6 hours ago, robtheplod said:
Following on from this as I'm looking to control my Webasto via a relay i can remotely activate. Using the above equipment I'm assuming the device works by connecting A1 and A2 ... can anyone confirm? (mine is analogue) - trying to get a clear idea of the wiring..
I sorted mine very easily. All you need to do is send 12v + down the black wires with the negative connected to the batttery ground to fire up the Webasto. My google nest is working perfectly and I can fire up the heating remotely if needed.
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5 hours ago, LadyG said:
Burning plastic to me is just asking for pcb's to be sent in the the earth's atmosphere where it stays forever. I'm not up to date with incineration ..........
No, you certainly aren't. You dont make PCBs by burning plastic and if you did they wouldnt be in the atmosphere. They are heavy molecules so would settle on the ground hence remain in the environment.
You are mixing up PCBs with Dioxins. Dioxins are even worse than PCB and are made by burning plastic incorrectly. They will not form if the right combustion conditions are met. Therefore well run incinerators are no problems. Badly run ones are. Dioxins too will not persist in the atmosphere but agglomerate and contaminate the soil etc.
Dioxins are dependent on Chlorine being present in the plastic mix so burning PVC is particuarly bad.
Off course burning anything that could contain plastic on a solid fuel stove could generate dioxins as the conditions are usually well away from the combustion temperatures needed for the optimum burning of the plastic.
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19 minutes ago, rusty69 said:
So, trawling though previous threads, I found this comment from @Dr Bob Trust him. He's a dogtor. Anyone got a data sheet for the epifanes or ballastic?
Yea, and my comments haven't changed.
Epoxies are hard rigid coatings that work by stopping oxygen and water getting to the substrate. They are excellent at the job due to their excellent adhesion to well prepared steel.
They will not work well over soft single pack coatings. You may get some years out of them but its a poor solution.
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46 minutes ago, Loddon said:
Are you sure its analogue and not W-BUS , if its W-BUS you will need some form of converter
Not a clue. My bus pass has now expired.
The guy's next door system works fine - with the same webasto heater and a google nest. I just needed to know how to wire it and Tonka's picture shows that.
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2 hours ago, Tonka said:
Ok, thats the heatmiser which looks totally different to the google nest. The nest has a red +ve and brown -ve feed which I will take from the boat circuits then has a wire out that is the 'call for heat' wire to the webasto.
I cant see properly from the pic but there seems to be 3 wires from the square female connector - a red (so +12v and two others. I suspect one is black and goes to the A2 - so that is the 'call for heat' and the other one is brown and goes to the unmarked screw (or is it a -ve?)
On my webasto switching box, I have a red, a brown and 2 blacks. Is it any of the two blacks I need to use?
Edit
Ah rather than just looking at the picture, I have now read the words (I am a muppet.....whadyou expect). Now clear. I'll try and wire it up on the weekend. Many thanks.
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1 minute ago, Moke said:
Doesn’t the Webasto wiring have a little square plug on the end of it? That should plug into the controller…..at least it did on mine.
Yes, its a little square plug with the 4 wires.
I want to ditch the controller and connect the wire that fires up the webasto to the google nest. Is it the black one?
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I'm getting cheesed off with my Webasto control thingy giving me little control. Great, you can program it to come on 3 times a day but it never switches off.
I'm going to fit a google nest but what wire do I need to connect for the 'request for heating'?
Looking at the 4 wires going into the controller, there is one red, one brown and two black. I assume from looking at wiring diagrams the red is the +ve, the brown the -ve and the blacks then must be the request for heat wires.
I am guessing if I put 12v down the black wire from the google nest, the webasto will fire up.
The guy on the boat next to use wired his up that way but he's not around to work out which wire he used!
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42 minutes ago, ditchcrawler said:
I was reading of one who uses worms to help composting on board
Worms are a good way to compost but only at low temperature. I think the max is around 45°C or maybe even less (<40°C). Once the temperature gets to the high 30's, the worms will start trying to get out of the box so not pleasant.
If you tried to take the box over 40 ish then you'd be killing off the worms - so using the roof to get to 50 to kill off the pathogens aint goin' to work.
I think Tiger worms are more temperature resistant but you still couldnt do it on the roof.
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1 hour ago, Mike Todd said:
A good example of what happens when part of a service is subcontracted - each subcontractor (sub)optimises their own part of the system. In this case the 'rules' may well allow the recycling collector to get a better profit by not accepting stuff that gets in the way of their 'system' but the rest will go somewhere. As a result, it is highly likely to end up in landfill with an increased cost to the LA and hence the rate payer. Indeed, the Landfill Tax was intended to put pressure on waste managers to try harder with recycling. If the LA is properly auditing itself then they may want to push back on this contractor, perhaps by changing the contract terms next time around. Too many people, esp LA staff, think that setting up subcontracts is easy - until they meet suboptimisers. If lucky, they learn and turn the screw next time but sadly some are not that well managed. (CaRT is a good example and they are gradually working what works and what is better kept in house - interfering politicians willing. The use of volunteers is similar)
That all assumes land fill is the main route to dispose of our black bag waste.
Unfortunately (or Fortunately?) it isnt. The majority of black bag waste goes to incineration these days and incineration costs are adjusted to match the landfill tax. This is the nub of the problem. The waste companies ie Biffa, Viridor etc dont want poo in their incinerators. It has less calorific value than the average so reduces margins. They happily take nappies because of the plastic content which is higher in calorific value than most of what they put in. They can stop getting the dog poo and some of the human poo (the 7Kg limit) via their private contracts...but its all about money. We deal with all of these waste handlers with our involvement in Plastic recycling and it is all down to margins.
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10 minutes ago, peterboat said:
I am assuming my compost picks up water the ground? Or is from the plant matter I put in ? It seems to work but over 9 months as I said earlier
Your water is coming from the water in the stuff you put in, or rain ingress afterwards.
My experience of composting in the garden was that the heap always got too dry but I didnt have a clue what was needed.
Water is needed as the bugs 'swim' in the water to get to the food. The compost has to be in the ball park of the right 'wetness'. Too dry and the bugs cant get to the food, too wet and the air doesnt get in and you start to get anearobic decomposition. In the lab we measure water content as per the test schedule using scientific meters. The way to do it in the field is to pick up a handfull of compost and squeeze it. If it drips it is too wet, if it doesnt drip it is too dry - ok extreme - but you are looking for something just in between. In practise, I never add water but if a box on the roof was looking a bit wet, I just leave the lid off for a few hours on a hot day. Its not really that important but you dont want the compost bone dry or swimming in water.
15 minutes ago, tree monkey said:Interesting thank you.
I think this is the real issue with compost bogs, they have been sold as a easy alternative to pump outs or cassettes, in reality they require work, which I am sure becomes routine eventually but that initial learning curve is steep.
They are not for me tbh but for the right person they obviously are a good alternative
Agreed.
It becomes a very easy routine but with no need for any hardware maintenance.
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1 minute ago, doratheexplorer said:
An interesting post, Dr.
I know a bit about composting (but clearly not as much as you). I'm content that composting successfully is possible on a boat and that everything you say is correct.
The problem is that for the average boater, it's very easy to get it wrong and any consideration of human behaviour would suggest that encouraging most composting loos will lead to unpleasant human faeces being put in bins (a bag of shit is still a bag of shit even if it's not as bad as a bag of shit and pee). The only possible way forward is to have dedicated emptying points for this material, which is then taken away to be composted properly. This still leaves 2 problems:
1. Who pays for that?
2. What happens when the solid matter is inevitably contaminated with urine by an idiot boater?
I do agree with what you are saying but I am not suggesting everyone changes to separating toilets with composting on their boats. Exactly what you say will happen. The reason for posting on here is that there is so much aggression towards this toilet type that it appears as bad, illegal, the devil - and that needs balancing out. Those people who can compost successfully (and that is everyone if they put some effort into it) will have a much superior form of toilet for their boats.
During last summers crawl around the network, we were moored up at Red Bull filling up with water when two old dears turned up. She was mid 80's, driving her 90 year old looking hubby with his trolly with cassette towards the Elsan. Their boat wasnt in sight so they must have been dragging this casssette for at least 15 mins (the speed they were going) and you could see it was a struggle. God knows how he would have lifted it up to the Elsan. Anywho, that didnt matter as the elsan was blocked and out of order. I suggested to Mrs Battleaxe they may want to consider as separating toilet. "Oh no, their illegal, you should be locked up". I swiftly withdrew. If anyone would benefit with this type of toilet it was those two, but no, poisoned by the words we here on here. What a shame!
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23 minutes ago, waterworks said:
We can't live without producing and relying on CO2, the idea it must be seen as a pollutant on a small scale line this is just nonsense.
It just shows the lack of inteligence in some people.
What on earth do people think happens to their poo when the flush it down the loo. It biodegrades in the system further down the line creating CO2. That is nature. DUH!
People seem to have forgotten about the carbon cycle. Plants decay and go to CO2. Living plants pick up that CO2 to help build new cells. That cycle has been going on for a few years.
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8 hours ago, tree monkey said:
Temperature is the way to monitor how well the process is working, Bob is suggesting 60 degrees from his lab work, so that seems reasonable, so say 60.degrees for 2 weeks, maybe Bob can give a more accurate time scale for full composting
I have a slight issue with this, i am slightly skeptical that this temp can be achieved in an small uninsulated box in winter, I think the "hot box" composters are insulated to facilitate this but as I remember volume of material is also important, again maybe Bob can give some help with this.
Above is an extract from the ISO 16929 test method (EU standard) for the temperatures that have to be used when doing the fragmentation test for industrial composting. The temperatures are deemed by the standards body to represent what happens in an industrial Windrow compost heap (but that's another story).
In our lab test we have units similar to the mini hot bins operating for the 12 weeks of the test at this temperature. Everything that is used by industrial composters is fully composted after 12 weeks at these temperatures - note most of them avoid anything man made like cups, plates, wet wipes even if they are stamped compostable.
These temps CANNOT be sustained in a small uninsulated box. You can achieve them easily in an insulated 50-100L box but only if you feed them regularly ie twice a week. This is the basis of the mini-hot bin. Go to their web site and see how they work. They do work on boats but you need to feed them kitchen waste as you wont have enough poo to feed them so you then end up with loads of great compost - but what then do you do with it. Our 120L a year is fine for our pots but I guess with a hot bin you'd make over 300L a year. Keeping the temp up at these levels is easy with a hot bin.
For us mere mortals trying to compost smaller quantities ie 20-40L in an uninsulated box, you will never achieve any real temperature rise, so using the boat roof as a radiator between April and October is the answer to get the material up to 50-60°C to assist in killing the pathogens (along with time) - see the humanmanure book. Hence the 6-9 months compost time depending on season. You also do need to get the water content right and turn it regularly - once a month - when its on the roof.
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1 hour ago, MtB said:
Ah yes, now there's another question. What bugs? What if they don't notice the composter full of poo-food and the process never begins? Is it a bit like keeping the sourdough starter going?
This may seem like a banal question to someone experienced with composting bogs but I'm not likely to shell out a four figure sum for one until I feel confident I understand everything about them and how its done.
Mike,
I dont know enough about the bugs to answer you question properly, other than they are everywhere.
When we do a fragmentation test, ie to see if a bit of plastic packaging is compostable, we cut some 10cm pieces of film up and put it in something that is very like one of the mini hot bins, charged with 50L of 'feed'. The food is chosen to work the bacteria hard for the 12 week cycle. We mix up the feed - usually a blend of food waste, paper, card, and other stuff (ie a blend of green and brown) and put it in the bin. Always, 2-3 days later the temp is up at 60°C with the bugs chomping away. I dont know what the bugs are but they are always there. They are in the food. They are on the paper. We always put in 1-2Kg of aged manure (but less than 2 months old). This is all done accurately with a known recipe. It always gets to temp even without the manure.
I guess it is nature. Leaves fall from the trees and biodegrade. That is the bugs in action.
Keeping sourdough is not that easy as it takes a while to get going and you need to keep it at the right temperature. This 'reaction' is much quicker but yes, is essentially the same. The bugs are all around us.
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10 minutes ago, Tony Brooks said:
It will look and,smell and feel very much like garden soil that has been worked and dressed with compost for many years. I suggest you don't feel it until you have inspected and smelt it first. However I am far from convinced it is that easy to do hot composting on a boat. Garden-wise the usual minimum size of the heap is said to be 1 cu. yard/meter. However my BiL's so called hot composters are smaller and do no such thing as far as I ca see, they just cold compost. Parts of my compost bins do get hot in places and at times, usually after grass clippings have been added, but I have never felt uncomfortable hand heat and am not sure it would be hot enough to destroy human pathogens. I think to do hot composting of human waste I would temperature logging unless I could be sure the complete compost will never be used on food crops.
I think this is the problem. The normal Jo in the street will not believe composting is possible because of their experiences in composting garden waste. Exactlly where I was 3 years ago. However now having seen close and personal these mini hot bins (circa 50L volume) generating 60°C + in 2-3 days and holding it up there - and seeing how we do our lab tests keeping samples up in the 50/60°c range and them fully composting down in weeks, you start to understand what composting really is and how it works. Industrial composting works in 12 weeks. Fact. We cant do it that fast on a boat but 6 months is possible.
25 minutes ago, MtB said:In that case I revise my question. How would one know if said hot composting has been done properly?
What does "done properly" mean exactly, to a hopefully open-minded layman like me who is half considering a composting bog but never seems able to find proper, fully satisfactory answers to my reams of doubts?
Properly means that you compost until all the material that can be composted is eaten by the bugs. When there there is no food to be consumed by the bugs, then the material is said to be fully composted. The Rottegrad scale is used to determine completion of composting. An alternative is to measure the volatile fatty acid concentration of a compost and it must be below the set value (meaure via ion chromatography of an aqueous extract). We do this in the lab. It is pretty obvious though that you can visually assess it as well.
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1 hour ago, Jerra said:
I have two questions.
1. You say you used the compost for pots twice a year. This implies that at times the pots are emptied to be filled with new compost. So what do you do with the "old" compost from the pots.
2. I think organic must mean something different to you than it does to me. You said "i think the key here is that the 'highly organic waste' is no longer highly organic after composting." Are you implying the material somehow changes state from having organic origins to not have organic origins?
The old compost in the pots goes on the marina's compost heap.
The bacteria that biodegrade the 'food' breakdown the long carbon chains releasing CO2 into the atmosphere. Therefore a highly organic feed becomes less organic as it is loosing CO2. In the lab, the main test to determine if something is biodegradeable (ISO 14855) is to put the test specimin in an oven at 58°C for 6 months and measure the amount of CO2 that is given off. A product is said to be biodegradable if 90% of its carbon is converted to CO2 ie there is very little organic component left. This is why the product going into the composter may be highly organic but the product out is totally different. It is not human poo anymore. Now most food waste (and hence manure) is a complex mixture of Carbon, nitrogen and oxygen - especially if plant based - so it all doesnt disappear as CO2, only the predominantly CH2 bits of it (ie the long chain fatty acids, the triglycerides etc etc). I dont know what the cellulose type molecules get up to (the ones built on lots of C,N and O). Its too complex. If you do any digging, let me know.
That is aerobic composting. If you look at anearobic digestion, a different set of bugs operate with instead of turning the CH2 chains to CO2, turn them to CH4 (methane) and other organic species such as acetic acid.
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1 hour ago, haggis said:
Thanks, Dr Bob, that explained a lot of the "mystery" of composting on a boat.
I have a couple of questions. You use 3 similar sized boxes and always put the turds into box 1 then later transfer them to box 2 or 3. Why not just use the three boxes in sequence? Ie when box 1 is full, start putting the turds straight into box 2 until that is full then start on box 3?
My other question (from someone who can be squeamish) is do you wash out the boxes between use and if so how and where on a boat do you do that?
That sort of raises another question (sorry!) about the cleaning of the turd box in the loo where the contents (before being moved to another box) will be more turd like and uncomposted?
Haggis
Thanks Haggis.
I have a 40 litre on the cruiser stern. A heavy duty HDPE box from B&Q. That gets moved into 2 cheapo 20L boxes on the roof. Moving the stuff mixes it up. Remember the oxygen? You do need to mix the boxes occasionally so transferring it helps. I dont usuallly wash box 1 as the residue has all the good bugs in it. Ditto the 20L boxes. These are small to get a bit more surface area on the roof to get more heat in in the summer. Box 3 which does get the final 3 months of composting I do wash out when I am near a tap as that has essentially finished composting.
The turd box in the loo hasnt ever been washed out in 2 years. I scrape out the solids with a trowel. It doesnt smell.
I probably spend no more than 10 mins a week managing it. With our pump out I used to have to strip the vacuuflush unit twice a year when it broke - an hour each time, plus the time taken to do pump outs etc. Its a lot less time consuming than pump outs or cassettes.
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12 minutes ago, George and Dragon said:
So, what you're saying is that composting needs to be an
industrialmanaged process - chuck it in a bin and forget about it doesn't work.Personally I don't spend sufficient time on-board to make the change from the existing system and since I have absolutely no interest in gardening whatsoever it's no great loss to me.
Good to read your report but is there usually an 'h' in coir?
There is if it is singing
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11 minutes ago, MtB said:
How do you know for sure the composting process worked and finished and there are no pathogens left in it?
Just by looking at it? That doesn't seem very reliable to me. I'd like to see a testing process.
Visual assesment is a good way of seeing the quality of the compost if you have a baseline to compare against.
Have a read of the Humanmanure handbook - available free on t'internet for info on pathogens and temp/time requirements.
The OECD 208 test is done in the lab for ecotoxicity for seedlings.
The point I am making is that if it is done properly then the waste is fully composted in 6-9 months and no poo remains. You dont need then to test every batch. You can see if it is right. ie the material changes from a box of poo turds to a box of fine soil type material. Once you've seen it happen then you will know what I am talking about.
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9 minutes ago, MtB said:
At risk of being labelled a crocodile, I'm still puzzled about how/where one disposes of the compost. What sort of volume per 12 weeks is produced? Is the volume small enough to all disappear into houseplant pots?
We produce 40L in 12 weeks. Over a full year it decomposes to circa 120L. We werent on the boat a full year but put half in our plant pots in April and half in the pots in october.
2 minutes ago, magnetman said:I'm not against the idea as it does seem interesting.
However it has to be said that storage on canal boats is a relevant point. You don't have all that much room to keep things. Priorities change. I once found several bags of smokes less fue discarded by a bin store simply because it was no longer winter. I took the fuel and kept it for a rainy day.
I think a similar situation can occur with the storage of the output. It is possible, and in a lot of cases or course it won't happen, that the storage of the product will be viewed as less of a priority than disposal. This is where the issue will occur.
Definitely good for people who are "into it" but possibly not a suitable solution for wider adoption.
Fully agree with you, but it is easier than you think.
11 minutes ago, TheBiscuits said:When shall we three meet again?
In thunder, lightning or in rain?
Dunno,
wheres you goin' be in May? I'll bring a brolly.
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2 minutes ago, mrsmelly said:
Ahhhhh, now I see. It did take me two hours to read the thread though. Whilst I would never have a shit in a bag system myself, your undoubted expertise rather than google type expertise, that certain posters use is nice to read. It has been of assistance to me in one way already. I bought this boring house thingy nearly two years ago, it had/has a large compost pile in one corner of the garden that seems to do nowt but get bigger!!.
If I bought an eco fan and mounted it at the side of the compost would it aid the bugs doing their job or not?
I remember writing something on eco fans a while back. I think that was longer!
Turn the heap. That's what you are doing wrong. Problem is it is too much like hard work to turn a heap so it never gets done so it never composts down. Let the heap get to a critcal size then sell the house and buy another with a smaller heap.
2 minutes ago, frahkn said:I have had a composting toilet on the boat for 4 years now, so it has been in use by two people for two years (we only spend half the year on the boat).
I would not change it now and for obvious reasons, I am not particularly interested in discussing toilets with people who have no practical experience. They can bring little of substance to the debate.
Dr Bob mentions "disgusting" as a trigger word in recognising these people, "bucket of shit under the bed" is another useful trigger.
Agreed
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3 minutes ago, tree monkey said:
An interesting post and I can certainly agree about the lack of basic knowledge about composting, my knowledge is practical rather than scientific but ranging from allotment scale/small garden and small estate, mostly "cold" rather than the "hot" that you are talking about, so 12 months as apposed to the 12 weeks.
Anyway the issue I have is still the disposal of the material properly composted or not and is related to the oft mentioned "it's a fertiliser so it must be good", the careless disposal of highly organic waste can fundamentally change a habitat, I also admit that most canal side habitats are unlikely to be negatively affected by said disposal but there might be, so what I'm saying is it should be standard procedure to dump the compost in an appropriate location and spread in an area that will benefit
i think the key here is that the 'highly organic waste' is no longer highly organic after composting. The bugs reduce the waste to compost. Once our pots are finished with they go on a compost heap. I agree with you.
Painting bilges, minimum duration for Danboline to be allowed to get wet.
in Build Blogs
Posted
My god! Richard's still not going on about Brexit is he?
Aye, still moored up somewhere east of Brum.