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openspaceman

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Everything posted by openspaceman

  1. The kid will stay completely still even if discovered and only start squealing if touched, it's a survival trait and still to be found in domesticated cattle to some extent. When I first got a brushcutter I was doing heavy weeding of broom and chestnut coppice regrowth in a failing douglas plantation and my saw passed right over a roe kid, it stayed so still I though I must have hit it. I still have a photograph the ranger I summoned took somewhere, complete with sawdust on its spotted hide. It had stayed put for the hour or so it took me to find him (well before any mobile phones).
  2. This is basically what a late friend , a biochemist and forest manager, told me. Too strong and it traumatises the plant and it doesn’t translocate. A bit like whisky, it hits the spot quicker with water.
  3. @Khriss go and join David Cropper on the naughty step
  4. I'd have said s. intermedia as the bottom leaflets are not separate.
  5. I'm so long out of marketing softwood, over thirty years really and last parcel of hardwood was probably twenty years ago but I'm sure you are right. I did not know band saws were not common now, last big sawmill I went to had a chipper canter followed by band resaws. Yes if the wood went into a normal mill alongside other "green" logs it would not get a premium or be used as high quality. The general rule in Forestry is that small amounts get subsumed into the next lower grade. The only hope would be if the premium timber were kept for own use or a niche where its superior strength would be recognised. If I had owned woodland near to home I would have pruned and thinned simply to be able to enjoy the resulting timber, standing. I still walk past oaks I pruned 30 years ago and wish I had been able to continue another lift as they are growing fast and clean, being on sand they will shake if left to a long rotation.
  6. The point being that all the wood laid down subsequent to the pruning will be clear timber. The aim is to have a knotty 100mm core to 6m in two or three lifts Choosing the right trees to prune is a problem and then avoiding harming them during thinning. In slower grown stands in colder climates falling snow does the job for you. As we have little pruned timber here getting a premium price is the problem. Also net discounted revenue means that the cost would be unlikely to be recovered at felling.
  7. A user is only allowed to remove an immediate obstruction, not to maintain the full width of the right of way, which is the highway authorities duty if the path is adopted (normally being fenced in either side means the HA have consented to the enclosure and become responsible for the vegetation on the surface). I am a local volunteer path warden and not allowed to use power tools unless on an organised work party with risk assessments and warning signs plus a banksman. On my own I can only use hand tools and cut branches only up to 50mm. Then there are guerilla tactics...
  8. True and I bought my first telescopic silky for pruning douglas that was spaced 6' by 8' And that becomes doubtful unless you use of saw the timber to show the higher grade Sad but probably true. Will you get a sympathetic harvester driver in on a 5Ha site nowadays. It's different in Scandinavia because they have a culture of harvesting little sites.
  9. Was he? cut looks like a hand held
  10. Male hen harrier? Only going from the light colouring as I have never seen one
  11. Bearing in mind I don't sell or buy hardwood just collect for my own use, though in the past I did commercial work on dryers and chip stoking boilers, hence my interest in the science, I take what I can get, and don't turn my nose up at softwood. Felled in winter it can have a low moisture content and it does dry fast once split. Anyway the basic density of pine and oak from the blue book says 350 kg and 540 kg oven dry timber per m3. As pine is a slightly higher calorific value I would suggest when buying by cubic metre bulk loads the ratio should be about 70% the price of oak for similar heat output at the same moisture content. It will be lower for spruce.
  12. @Stubby avert your eyes That's what I did too: 1kg log at 25% mc wwb contains 0.75kg oven dry wood with 3.875kWh thermal energy. The 0.25kg of water needs heating to 100C from 20C with 83.6kJ, turning to steam at 100C with 564.1kJ and then raising to 300C (I still think ~200 is more realistic) with a further 100kJ which adds up to 0.208kWh. This represents 5.36% of the energy in the wood. Allow the same piece of wood to dry to 20% mc before putting it on the fire means you have the same thermal energy but now only need 66.88+451.28+80 kJ or 0.166kWh that is 4.29% This is not a rigorous way of looking at it as that 5.17kWh not only varies between species, part of tree and season when felled but it is a Lower Heating Value, it already allows for the water formed by combustion of dry wood. I put something here a couple of years ago
  13. I used 5.17kWh/kg for dry wood and my calculation gave 4.29% loss in steam at 300C.for 20% and 5.36% at 25%. I would like to know if people using flue temperature gauges actually see temperatures as high as 300C as it seems a bit high to me. Flue temperatures have to be above 100C at the chimney exit to avoid condensation with wetter wood but it would take a bit of working out what the dew point would be for dry wood, it would be less than 100 because the partial pressure of the water vapour would remain above the partial pressures of all the other combustion gases down somewhere below 100C. Of cause the chimney would be absorbing some heat and depressing the temperature of the column of flue gases, more so if it is not insulated. I use this as a feature, so the chimneybreast's thermal mass keeps the house warm after the fire is out.
  14. You've got it Actually the latent heat of water does vary with temperature but your 0.6kWh holds good for the approximation we are looking at. When you burn wood it changes from a solid with associated moisture to ash (a solid but very small part of the original mass) and gases/vapours that go up the chimney at whatever temperature it leaves the stove, this mix of gases carries away heat from the wood that never gives you benefit as heat in the room. If the moisture content of the wood is high then you lose that 0.6kWh for every kg of moisture that goes up the chimney plus the additional amount of sensible heat it contains at temperatures above 100C. I guess most stoves run a flue temperature of 150-350C so this sensible heat of the excess water is also considerable. As you say wet wood is harder to burn cleanly, mostly because it quenches the burn, this shows up as smoke and particulates, Products of Incomplete Combustion, so some of the potential energy of the wood also leaves as PICs. Worse still is the business of excess air; because wood is a complex mix of substances that burn in stages we have to add more air than is what is needed to combine with the fuel to ensure enough oxygen meets the fuel to burn it out. Good wood stoves will use 1.5-2 times the ideal (stoichiometric) amount of air but this all has to go up the chimney at the flue temperature. Thus the massflow of products up the chimney consists of excess air, excess moisture plus the products of combustion (ideally steam and carbon dioxide, even burning bone dry wood produces water)). Worse still is wet wood tends to need more excess air than dry wood, hence increased sensible heat losses from the high massflow as well as extra steam. Bear in mind you need a stoichiometric mass of air about 6 times the mass of the burning dry wood because only 21% of the air is oxygen, the rest is nitrogen which has a free ride through the fire but still carries away heat up the flue, increase that with excess air and you see what a heat robber it can be. I think it does but it is a tiny effect only of consequence when discussing how much moisture is regained as dry wood picks up moisture again as the humidity increases in the winter.
  15. Yes, the thing is there is much wringing of hands and wailing about using wood to dry wood but the physics of it is all the same , energy is energy whether we use solar heat for the drying or intercept it first on its way to gaining entropy and store it in a tree. The bigger argument is whether our value system, money and wealth, are good measures by which we make decisions. If not we need to come up with another one that functions as well as this. @gdh has put some numbers on it and it's simple to work out the difference in energy available in 25 or 20% mc wood but the rest is so many variables. One would need to know the parameters of the stove and the flue temperature to decide on which was better for which stove. From the supply side one would need to know the cost of covered space, seasonality of labour, cost of capital equipment etc. In practice a person makes simple decisions to run a business and one thing leads to another, if another business makes different decisions and as a result out competes the first then it is more successful, that's what drives capitalism, not basing decisions on what's good for the environment, that's what regulations do to keep everything acceptable to most of we also rans.
  16. Does anyone know anything about the hydrostatic transaxle on these flails. The input pulley seems to have a bit of slop in it and I wonder if these things can be worked on or is it a case of running them to failure? @GardenKit or even possibly @PeteB
  17. Interesting I've not seen one. When I tested our tracked chipper at 35 degrees for the CE technical file I found the Hatz engine oil pick up had to be factory modified.
  18. For the time being I've drawn it at strimmer plastic but I still wear polyester-cotton clothes
  19. Make sure the engine oil pickup doesn't get uncovered at extreme angles
  20. My apologies I snipped badly and somehow it mixed up the attribution, I don't know exactly how but it is something to do with the quote selection feature when I highlight the specific bit I am replying to.
  21. That too but I was considering the plastic one rather than the link he gave
  22. It shows how there's always someone out there trying to catch out someone in the limelight, who'd want to live in that situation even if he's a pernicious creep.
  23. I wonder where all the line worn off ends up

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