agg221

It's a tricky one to guess how long willow would last. My roof is wheat straw thatch. If left on the ground it would rot away over a single winter but correctly applied it lasts 25yrs. Willow is considerably more durable than straw if left on the ground so if used as a thatch it may last well, but it's not just the material, it's the way it is layered and packed so that the water runs off it, only really eroding the outermost layer. Thatching is an art (I can't do it, but it's fascinating to watch the thatchers at work), and willow would be much harder to do this with properly. If not densely packed then rather than running off, the water will run through, which will, I suspect, leave it damp and therefore rot it much faster. I think the fundamental problem may be that it isn't possible to fake the look of thatch without actually thatching. Alec

An old thread, but you might find it useful as it has pictures and explanations of approach: Alec

A brass wire brush can work quite well. Soften the varnish with stripper and then use the brush with the grain. Do not use a steel brush - too hard and the little bits will stain blue. Once you have the varnish out of the grain you will have open grain again, so your finishing process will need to fill this. It depends what look you are going for, but if you leave the grain open, dirt will collect down there and it will end up looking pretty much like it does with the residual varnish. One way to deal with this is to use a curing oil such as Danish and build up enough layers. An alternative is to apply a curing oil (tung, linseed or Danish depending on your preference) and sand the surface with the grain while wet, using something around 320 grit to create a slurry, then rub across the grain to push the slurry down the pores - I do this step with the heel of my hand. Then wait for the oil to cure before touching it. A couple of goes like that and the pores are filled with a fine sanding dust/oil mixture which matches the colour of the wood perfectly. Alec

I looked after an orchard in Kent for over 30 years which was grown on semi-dwarf stock. I currently have my own which has apples on MM106, pears on Quince A, plums on St. Julien and cherries on Colt. These are around 11 years old, planted at 12' spacing and the apples do not need a ladder, so it can be done. There are many approaches to fruit pruning. The first question is the form you are going for. I would suggest a fairly low bush is what you are heading towards, which will help keep the tree workable from the ground at the expense of easy access underneath, so you will need to kill the grass. I use a layer of cardboard covered in chip which has been stacked for a year or so, which isn't the prettiest but works fine. Note, this is not a modern orchard form, producing lower yields per hectare than a very dwarf stock grown densely on a permanent vertical stake, but these are short-lived, high input and not really very attractive aesthetically. With regard to pruning, think of a stemmed glass. That could be anything from a standard wineglass to a champagne coupe. Anything growing up the middle comes out. You need main branches arranged roughly evenly around that - usually four or so. From above, they would look like spokes of a wheel but actually they come up at an angle. Simply cutting off anything too upright or too low is an option, but cutting tends to result in more vigorous growth in response, so an alternative approach is to bend the existing branches to shape. This can be done using string or poles. There is an art to knowing what will bend, how far, and create a strong shape when it does, but generally lowering the branch angles like this tends to make the tree focus more on fruiting than growth, keeping them smaller. Once you have bent the branches and secured them where you want, you can decide what is actually in the wrong place, and what doesn't fit your pruning method. Methods - two principle approaches, one is spur and the other renewal. Spur pruning builds up a permanent structure of main branches, sub-branches and laterals, filling the space but keeping them a good 3' apart vertically so on a small tree like this you would probably aim for a single layer. There is an excellent photograph showing this in The Fruit Garden Displayed. The approach relies on cutting all new growth back each winter to the fruiting spurs, leaving only 3 buds, and then taking back some of the spur system itself every winter to keep it from becoming overcrowded. Spur pruning is very formulaic, using a lot of very small cuts. Renewal pruning by contrast starts from the premise that nothing other than the trunk and probably those first branches from it is necessarily to be regarded as permanent. Everything else can be taken out when a new branch starts to form which could replace it. In theory, you would pick fairly evenly placed growth along the main branches and leave it alone for three years, then cut it back to the lowest side-branch on that piece but in practice you always end up with more of a mix of cuts coming out - some three-year old material gets an extra year, some younger material gets too crowded and a comes out a year early, some side branches can be replaced with something better if you bend it into place, sometimes by anchoring it to something else (temporarily crossing branch) and cut that other piece out the following year. This makes renewal pruning far less formulaic and reliant on judgement. Typically, renewal pruned trees look more natural as the new growth is not tipped off, so they are more straggly. They are pruned with far fewer, bigger cuts. You can of course switch between these two methods at some point, but not flip-flop between them annually. A couple of things to bear in mind - firstly, some varieties are tip-bearing so if you try to spur prune them you will take all the fruit buds off. Secondly, spur pruning drains the tree more as all new growth is constantly being cut off, so it will gradually slow down whereas renewal pruning can be used pretty much indefinitely (the trees in Kent are now 103 years old, which is pretty good for dwarf stock). The yield is better from spur pruned trees and they are easier to harvest. I would look at the centres of your trees first and see what the branch angles are like, and then think about what will best achieve the formative pruning. You can afford to cut a reasonable amount off without the tree going mad and they aren't that dense anyway, but if you do get water shoots forming (vigorous, vertical growth near the middle) then pulling them off next summer is easier for dealing with them than cutting them out the following winter. Alec

I'm not sure whether I should admit that this was actually my 10yr old daughter's joke... Alec

I don't know, what is black, made of plastic and travels around the oceans? Alec

Why is 10+ 10 the same as 11+11? Alec

I tried a paraffin blowtorch on one of my conifers once. That was quite quick, and completely painless.... Alec

Yes, but then you knew that... (Just wait until you don't need to go anywhere - I can bore you for hours!) Alec

It is quite impressive (and completely natural). All six chickens lay different eggs so are easily identifiable. That one came from Raven who is (unsurprisingly given the name) a Black Araucana. Everything was wrong - she was introduced later as a single chicken to an established flock, my wife got her because she wanted one, but particularly this one because she felt sorry for her as the runt. She had a damaged leg, couldn't stand properly and she had a really bad mite infestation. Extremely hard work for six weeks to get her recovered and introduced to the flock (involving a lot of controlled interaction in the garden with judicious use of a water pistol to manage interaction with the others!) Now, she is smaller than the others but makes up for it with her feisty nature. She will always walk slightly oddly but she is happy and alert and extremely productive - over 250 eggs last year including two double-yolkers. They are definitely entertaining characters! Alec

I like the trampoline run. It does remind me - outdoor space with a roof is a good idea, and also a bit of wind shelter. I modified the coop we bought by putting it up on legs and boarding in two sides, the egg box extending out over the third. When the weather is cold and wet they huddle up under the coop, or wander around the other bit of run I built a roof over. We bed them on hemp shiv which desiccates the droppings so they can be picked up in clumps every morning. The coop has a pull-out tray. That keeps the coop itself clean and stops the smell being so bad. Between my previous post and this one, the first chicken has just come back into lay. Alec

I have some which might fit what you are looking for - two failed bat willows grown for J.S.Wright which were not maintained properly before we bought our place so don't have enough clear lengths to make sufficient clefts to justify harvesting but I think will have what you need. There are two logistical challenges. The first is that they need to be felled - coordination with @AHPP needed here. The second is that they are in North Essex, but it does look like I will need to drive down to Devon with the plant trailer at some point in the next few months. There are a few unknowns in the above, but if it comes together it might work? Alec

We have six large fowl of different breeds. They were chosen for a laid back temperament and we got them when they were just off the heat lamps from a place near Stowmarket (except one which came a few weeks later from a different supplier as it was a breed my wife wanted). Large fowl still aren't that big - even a Brahma is only around the size of a cat . I bought a self-assembly coop as I couldn't buy the timber for less. I then built it in to an integral short run, with other bits of run that move separately and extend it. That way it was fairly easy to move around the garden every couple of months. At this time of year we have to throw down straw in the run but otherwise it's not too muddy. Ours are currently off lay, but they are productive spring/summer. They probably sit halfway between pet and livestock, in that they aren't really friendly but they accept being picked up by the daughters, and they won't end up in the pot when they stop laying. When regulations permit they get let out for a supervised run around the garden for an hour or so a day. They seem quite happy, don't try and escape (they could easily do so if they wanted to). They are not clipped, so they can fly but it's too much effort (definitely lazy breeds). In a small flock like this they are all identifiable by their unique characters. If at all possible, get them all from the same place at the same time. If not, get them in groups. The flock mentality excludes outsiders and introducing a single chicken is extremely hard work, even to a very laid back flock like ours. Alec

I suggest having a look here: https://www.chainsawbars.co.uk/chainsaw-mills-and-milling-kits/ Rob D of this site runs the company. None of the the options are bad, just different prices with different levels of features. I suspect you will be wanting the Ecomill. It's worth buying the longest you can justify - 36" or 48". You can always shorten them up - most ridiculous I have run is lending the mill at 48" to someone with an 18" bar, but it works fine. You can then use it full length in the future if needed. Even if you take the dogs off the saw you will lose about 1.5" of bar length at the powerhead end and about 5" at the nose end as you can't clamp on the sprocket. Bear this in mind when considering the size of the mill and the size of the log. Trimming a few knobbly bits off to get through is OK but constant trimming along the side quickly gets tedious. That determines whether your current bar is long enough. I would say it makes enough difference to performance to justify buying a ripping chain along with the mill. If you are going to have to buy a longer bar anyway, buy the chain to suit it and consider 3/8" lo-pro (does mean you will need to change the drive sprocket). It reduces the kerf by enough to allow a smaller saw not to be stressed and a bigger saw to cut quickly. The exception appears to be if you are running a 100cc+ high torque/low speed saw where it is more likely to break the chain, in which case I would stick with the standard .404 chain. Otherwise, that should be it. You will need a ladder or plank to make the first cut, and a way of holding it on the log, but there are many videos on this on Youtube. You will also need some sticks, bricks and a top cover so you can stack and season the timber without it getting rained on. Be warned, milling is highly addictive! Alec

It might be a nut, or it might be a seed, but there don't appear to be any allergic reactions to it: https://tungoil.co.uk/nut-allergies/ Alec

It's not a need as such, just a difference in finish. Most oils on their own tend to be quite thin as finishes, more soaking in than building up (Danish is a bit of an exception which is more like a varnish), leaving a finish that brings out the colour and grain as though it was wet, but you see the wood surface pretty much as you left it, so they tend to have a certain matt quality. Waxes build up on the surface and give a sheen but on their own they don't tend to give that 'wet' look that brings out the colour and the grain. If you put wax over oil you get a deep lustre which brings out the colour and intensity of the grain. It is also easy to maintain, just needing a bit more wax every six months or so. If you are very good at varnishing you can get the same look, but I always get a bit of dust or a few streaks in it. Also, when varnish gets damaged it is more of a pain to re-finish. Alec

I do like walnut oil and have used it in the past, but got slightly wary when I found that people who are allergic to nuts can also be triggered by the oil. I decided that since I couldn't be certain who might touch something in the future and there were other options I would stick to them, so tend to use linseed or tung now instead. Alec

Elm has interlocking grain which is often quite contorted, so sanding is a better option than planing. I've done several floors-worth of it, milling and through the thicknesser which gets it dimensioned but not smooth unless the blades are absolutely sharp. Do you want a gloss finish, a satin finish or a near-matt finish? Given that it will be a table top, it will inevitably be subject to some wear. I would therefore either go with a hard wearing varnish and accept that it will need occasional sanding off and re-finishing, or sanded in oil (boiled linseed or, for preference, tung, or even Danish). Once you have sanded to remove all marks, apply the oil to the level where the surface is wet, not just damp, and sand it over lengthways at about 240 or 320 grit and then rub the oil/sanding dust slurry in to the surface across the grain using the heel of your hand. This will fill the grain. A couple of goes at this 24hrs apart if outdoors, 12hrs apart if indoors, followed by a couple more coats simply wiped on with a cloth will give a solid finish which is easy to wax over, and if it ever gets damaged you just need to clean off with turps or a furniture restoration cleaner and put another coat of oil over. Danish oil can go on thicker and doesn't necessarily need the wax. Alec

If it's more rustic and you aren't sure that the wood won't move and open up a gap, or you can't get a perfect line along the join, a fairly easy alternative is to make a feature of the join and use butterfly joints. I can't draw them, but see link here for examples: https://mechantdesign.blogspot.com/2013/08/butterfly-joints.html If you use a piece of contrasting coloured wood, cut them right through with a saw, glue in and sand off flat then they will hold pretty much anything. Also good for dealing with splits. Alec

Looking at the area that 'zone' covers, it appears to include the M6 and the M62? Without wishing to dig through the paperwork, has anyone established whether the local authority is therefore intending to try and charge for use of motorways? Alec

Thanks - there is so much information around on these subjects that posts have a tendency to get rather long, but hopefully not too boring! I did a bit of work on phase change materials in around 2012, working with Northumbria University and a company which worked on Stirling engines at the time (run by a man called Drummond Hislop - who coincidentally went on to be involved in the establishment of HIETA which is one of the leading powder bed additive manufacturing companies these days, but the original interest was in the use of additive for advanced heat exchangers to improve heat transfer). We also had a partner up in Northumbria which makes heat pipes. Phase change materials have several useful properties - one is that you can store a lot more energy in a given volume which is particularly useful if you have limited space. What we were looking at was the ability to reduce energy use in domestic water heating so this was important for fitting it in to flats or small houses. The principle was that people usually run their boilers in the evening to heat the house which efficiently generates hot water at the same time, but whilst a well insulated house will hold its temperature through to the morning, the hot water tank has probably cooled down too much by the morning to be used for showers so the boiler gets fired up again which is very inefficient. If you could hold the temperature steady then you wouldn't need the boiler. This is where the second advantage of phase change materials lies - the energy input changes the phase rather than the temperature, so it is very consistent. You would need a very efficient way to get the heat out of the thermal store and into the water supply, which is what the heat pipes were for. In practice you need a much higher temperature thermal store than the water you are trying to heat, and again a phase change material is one way to achieve this, although of course you could just heat up anything so long as it doesn't vaporise (pressure management is not desirable). In practice, whilst what we were doing worked, it made it so far down the line, the funding ran out and there wasn't enough impetus to keep it going commercially (aka the Valley of Death in innovation terms). These days, the big advantage I can see is as a high grade heat store. For example, if you are generating power and have a high temperature exhaust, putting the heat into water limits you to space heating and hot water. If you can keep the temperature higher there may be more uses for it, such as cooking - imagine plumbing a high temperature fluid loop through a phase change heat store and around a converted Rayburn or Aga. Here, phase change materials help as they give you more compact storage so it's easier to insulate, let you get to higher temperatures so it's more efficient, and give you a very stable temperature which only starts to drop once the phase change has fully reversed. There is a substantial challenge though. Most phase change materials are not too convenient to handle. They are either low melting temperature salts which tend to be very corrosive, or organic waxes which are highly flammable. This makes the plumbing rather expensive. That said, recent advances in coating technology may make the molten salt route more viable. Alec

Responses are not necessary to the omicron thread - that wasn't why I posted. You are correct in surmising natural sciences - chemistry, followed by a rather odd engineering doctorate in materials, based on inorganic chemical synthesis routes. Some slightly random thoughts: Thinking back over the time I have been involved, various significant changes have happened. One of the biggest changes is the shift in the pattern of demand. 20 years ago, light bulbs were still filament, many houses still didn't have a computer and if they did, it was a tower PC with a CRT monitor, using a modem connection for the internet which might be on for an hour or so a day at most due to costs. Mobile phones were becoming common but were by no means universal (snakes anyone?). Houses were built to very poor thermal standards and there wasn't a single Passivhaus standard building in the country. Wood was still mostly worthless - people didn't have log burners and most people would be glad of an offer to remove a dead tree (which is where most of my timber for boat restoration came from, along with the living room floor in my previous house). PV was phenomenally expensive and nobody would have thought of putting it on a house. Solar thermal panels were coming in as the big thing just over 15yrs ago. The changes appear to be in pattern of energy demand as much as in the supply sources. Energy consumption from the basics such as lighting has dropped significantly across the board and modern motors are far more efficient, but the digital world places much more demand on power for devices such as phones and computers, and a lot more electronic connectivity within equipment such as boilers, cookers and white goods. This has probably pushed the base load up. This also relates to lifestyle. Are you able to batch up washing and put the machine on when the sun is shining, making direct use of PV to run washing machine and the weather for drying, or do you need to do a regular family washload at the weekends regardless of the weather and have to use the tumble dryer if the weather isn't good? These have a huge impact on the ability to make best use of an irregular supply vs. the need for more storage. Insulation vs. heat requirements are more tricky to estimate - the difference in heating bills between a brand new bespoke building meeting Passivhaus standards and a Victorian end of terrace with solid walls and no realistic route to insulating it without sacrificing a lot of space in the rooms is huge. That often means that, within very limited ranges, you are stuck with the fabric of the building you have. I wonder if it is useful to break down energy requirements by category. What I was thinking of was low grade heat for space heating and hot water, high grade heat for cooking, DC electricity and 240V electricity. It would then be possible to think about the total requirement for each and consider where that is now and whether that could be reduced in an acceptable fashion. This would be very much down to individual circumstances. I know the options better for canal boats and some of these don't apply, but for example on a boat the water pump can be replaced with a hand pump and a header tank, with a separate header tank for a shower where you pre-blend the hot and cold water. This substitutes manual work for electricity, cutting the requirement. I suppose the equivalent for a house would be using a gravity fed shower rather than a power shower. Whether someone sees that as acceptable or not is a personal choice. Other options might include the use of a pantry for food storage to minimise the size of the fridge, and at this time of year perhaps to substitute its use completely, and storing more food as dried and preserved goods to reduce the amount of freezer space needed. Gravity fed rather than pump fed is also a choice for some heating systems. HVO is not a cheap option, but it does enable both green and off-grid credentials to be met. There are then some CapEx vs. OpEx decisions that could be made. When we re-wired large parts of the house I investigated going 12V on the lighting circuit. At the time, knowing what I did, it didn't make sense but now I know more about how to source system components it would certainly be something I will re-evaluate when I come to re-wire the rest of it. Again, learning from boats, a DC circuit can be used to run many devices, including computers and televisions - even fridges and washing machines. If you are running off-grid, so power generation and storage is mostly DC, the more you run equipment on DC, the less energy you lose through an inverter. Many motor-driven devices such as fridges and washing machines are likely to run DC motors anyway, so it is doubly inefficient to step up to 230V AC and then back down again. Once you have got through all that lot, I think it should be possible to run a revised energy audit on what the actual requirements are. Firstly, it may 'find' some of the necessary capacity in savings and secondly the balance of low grade heat/high grade heat/DC/AC will determine what systems are most suitable and at what size. CHP would generally be sized to meet heating needs rather than power needs as otherwise the heat is going to waste, as per your Petter genset. Pure electrical generation without heat is tricky, particularly in a suburban setting. You are pretty much limited to solar I think. There are improvements here which make better use of space and produce more energy per square metre. The double-sided panels are interesting, as are CIGS. I think it is more incremental gains than step change at the moment, but the gains are big enough to be making a difference. However, unless you have enough space to install sufficient solar and electrical storage to cope in winter, you may end up with waste low grade heat. Heat and lighting demand will vary through the year. I doubt the latter makes much difference with LEDs, but the former definitely does, particularly if the electrical generating solution to meet base load generates heat. In theory you could switch between using and dumping it with a simple valve across two parallel systems - again, boats can do this with the engine coolant, varying between radiator loops and a keel cooling tank. What might be more useful is a higher grade heat store - running a coolant with a boiling point high enough to feed into a cooker. It would work on a modified Rayburn or Aga (the latter are already converted to 13A electrical supplies). It's a style of cooking that may or may not fit in with a lifestyle - very much about long and slow rather than nuking it in the microwave, but it does work. Again, a possible compromise. The systems I can think of offhand are internal combustion, external combustion, gas turbine and fuel cell. You have more experience than me of the problems with trying to run a cost-effective gas turbine. External combustion is the Microgen approach - I'm not really sure why it works out so expensive as it doesn't rely on exotic materials. The problem with Stirling engines appears to be that the power is all in the revs rather than the torque, so there are real efficiency losses when you step it down into an alternator. Fuel cells are attractive, but they all have their own drawbacks. PEM runs on hydrogen and works well but poisons up in impure gas streams. It also needs what would soon become a prohibitive quantity of platinum. SOFC as per RR runs on almost anything and doesn't have material supply issues, but it is a delicate piece of kit. The thin ceramic components are fragile, will break if you drop it, and and are not something that can be swapped out as they have to be brazed in place with complex filler metals in a difficult gas environment. Phosphoric acid fuel cells might be worth a revisit. They fell out of favour 30 years ago or so, but actually they might meet the need for cheap and cheerful. However, they are not currently available so far as I am aware, and are not exactly a DIY solution, so that would appear to leave the option of the most efficient diesel genset you can find, with good sound insulation and run on HVO if you want net zero emissions. This has got rather long! Alec

I did some work for Microgen a decade or so back. It's a good product but by their own statement it only really makes sense when you have a demand for a lot of heat to keep it running near continuously. Single domestic properties don't really work, but it is excellent for blocks of flats, leisure centres and similar. I have recently been doing quite a bit with a company that has installed a lot of CHP systems in the latter. Around 25yrs ago (worrying!) I used to work for Johnson Matthey developing catalysts for fuel cells. I specifically worked on reformate tolerant anode catalysts. The anode is the side where the hydrogen goes, with oxygen to the cathode. At that time, hydrogen was made by steam reforming, effectively the old towns gas process - water plus carbon goes to hydrogen plus carbon monoxide. The problem with the anode catalyst is that it really doesn't like carbon, which sticks to the platinum, covering it completely, known as poisoning, so there are no sites for the hydrogen to react at. This means the purity levels needed to run a fuel cell are phenomenally high. You can run a reverse reaction to remove the carbon but it takes a lot of power, so the overall efficiency of the system drops the more you have to do it. At the time, one of my colleagues was leading the activity to develop separator membranes. I am not sure that the technology has moved on that far since, as the shift from presuming hydrogen would be reformate to presuming it would be electrolytic and hence pure happened around that time. This means there may well still be some considerable technical development needed to create a cost-effective separation membrane which can run at a sensible flow rate. Irrelevant aside - my first patent was in this field: US5939220A - Catalyst - Google Patents PATENTS.GOOGLE.COM A novel catalyst comprising a Pt--M alloy wherein M is one or more metals selected from the transition metal elements or... Alec

Mine have been made from the stumps of elm suckers - the first one vanished so I made another. I find something around 6" diameter, dig it out about 6" below ground, cut off the side roots and round up the underground bit as the head and the very bottom of the trunk as the handle, carved down to a decent diameter as a grip. I have given it a serious hammering on froes and everything else and it has worn down rather than split. Alec

I realised I could probably give a more useful answer to this. First to say that I have no commercial interest in any system and do not own one, but have had some involvement in working with Carbon Compost Company professionally (not paid by them but by a third party). I have not seen Beau's system in the flesh, only on videos and photographs, but the data looks very promising. I do make charcoal, but only for my own use and I use a pit burn approach, which works well for the mix of biochar and charcoal that I am wanting to make. Some thoughts. Ring kilns are cheap but labour intensive. They also require quite a high level of operator skill, and loss of attention can result in loss of the whole batch. Retorts are easier to control, tend to give more reliable yields and are also much quicker per batch, but they are more expensive. Making charcoal is more labour intensive than making firewood. There is more time and effort invested in the product. If you have large volumes of raw material to process, or really you want to be working in the woods, charcoal may not be the most effective option - The Village Idiot's thread has some useful thought on this. If you have limited raw material then it makes sense to add more value to it - charcoal can be a good way to do this. However, you need to consider whether you can get the return on investment needed to justify a retort, based on how many runs you cna do with your available material. There is a fairly narrow window where there is enough to make it viable but not so much that you are better off selling firewood. The same window exists for a ring kiln, but in a different place. Whilst I have the utmost respect for the skill of using a ring kiln, personally the unburnt methane emissions which contribute 15x the global warming effect of CO2 make it a route I would not choose to take. That's a personal choice. There is definitely a market for premium British charcoal. However, to make the most of that you need to add marketing, sales and promotion. You will need to retail rather than wholesale. That requires a whole additional set of skills. There could be some interesting changes on the horizon. I would not want to rely on this but the Woodsure scheme may make charcoal a more attractive proposition, as may the emerging market for biochar and carbon credits. At the moment I am not aware of any retort which can process chip rather than reasonable sized logs/branches. This would open up the biochar market considerably. CCC's early products distorted quite considerably. Many changes have been made since then and you would need to satisfy yourself that this had addressed the issue. There are sometimes used retorts for sale. I'm not sure whether Beau has yet defined a route to market for his design. Alec