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openspaceman

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About openspaceman

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    Senior Member, User formerly known as catweazel

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    Surrey
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    openspaces
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    admin

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  1. How will you check them? One of the things @Woodworks and I have previously discussed is how moisture meters are calibrated and the same holds true for the tables of equilibrium moisture content he cited. Most lumber drying measures moisture on a dry weight basis. I think the recent legalisation for firewood is measured on a wet weight basis?? Now if the example of 21% moisture content being in equilibrium with air at 90%RH is based on moisture as a percentage of dry weight then that equates to 17.4% wet weight basis. Also look down the chart for cities in america, are they all seriously dryer than UK as not one of them shows an EMC of higher than 18%. I'd like to see a real experiment of a log of moisture content determined by oven drying suspended in free air under cover outside. @Mike Hill mentions airflow and this is far more significant than one might think because diffusion alone isn’t enough to move moist air away from the log. My little experiments with single logs point to this also as they seem to do better than logs in my log shed. I should have weighed some sample logs and marked them before embedding them as I filled the store in May. Just consider how wet roads dry out in a day without rain even in January, so drying is still taking place mid winter albeit not much but if the wind is free... A m3 stack of beech logs at 21% mc wwb probably weighs about 280kg and has about 53kg of water, to get it to 19% means removing 6.25kg of water and the latent heat of evaporation that needs is 4kWh ( the heat in a1kg of 20%mc log), the trouble is that if the moisture in the logs is homogeneous the temperature would need to be high enough to get to all the log and the heat losses from that could exceed the heat needed to vaporise the water. One way would be a first in first out queue blowing warm air from the first out end with maybe4 days log deliveries in the queue in an insulated tunnel to polish off the few kg of moisture. We can have a separate discussion on how come there is a need for legislation and about selling wet wood when everyone knows dry wood burns well and green wood doesn't. It's a bit like gun law once garage forecourts stop selling wet wood then the people burning it are likely not buying it but getting it free and burning on an open fire.
  2. On 6 Jan I brought a freshly felled piece of beech 1287 grams to the side of the stove at 48% mc and two days later it was 33%. At the same time I brought a piece of holly into the house and it was 16% from my log store. This is similar to what I have measured from my log shed since I built it a couple of years ago. Last Wednesday I washed my winch rope and strung it up in the shed, today, despite rain on and off all week, it feels dry but then I am in a dry part of the country.
  3. Arthur Cundey made two posts here 9 months before I joined and looks like got no responses, a bit of a shame as Cundey peelers featured in many yards and sawmills. Back to the today’s post and those angle grinder attachments; I have not used a cutter on an angle grinder other than the arborcut chainsaw tooth thing but find a cheap £50 750 Watt electric planer with disposable blades does a safer job of removing bark off single poles where the curve means a 4" wide cut is adequate. It's a damn sight better than the sharpened spades we had to debark potential telegraph poles with.
  4. Trouble is now I'm finding it all too easy to fall into being a couch potato and online warrior and this makes me wonder if I would have kept as active as I did if I had taken a desk job early on.
  5. I agree, it is surprising considering the trade is a bit of a luxury service industry, but can think of many reasons for this not least of which is that people have a bit of money which may normally have been spent on travel etc. This comes back to the way we as a wealthy society fail to provide for the parts of society heavily affected by changes. Just as we didn't plan an orderly retreat from mining, steelmaking, shipbuilding etc. and let those parts of the country, once the core earners, become relatively poorer than the elite finance professions centred on London. Instead we have created a situation where labour is is made inflexible by H&SE requirements for expensive certification. No we will never have a great reset, it's not human nature, but I'd hope for a bit more compassion as well as resilience and of course looking at those activities that are causing problems to the environment.
  6. It has to increase but the worst thing is that if the site does not have a neutral return back to the point the three phases separated all that current travels back by earth. This is because when you put a balanced load across a 3ph supply the sum of the currents is always zero, so no separate neutral required, all the current runs in the three phase wires. If one phase is missing something has to be provided to return the current when both of the available phases are the same instantaneous polarity. I never got that far which is why I chopped trees down.
  7. It's kW but as long as the motor rotates with little slip and no load very little current will be drawn until you impose the load of your saw motor onto it. Not having 3ph available to play with I am not sure but the second phase is 120 degrees out of phase with the other so a quasi rotating field exists, in much the same way a single phase induction motor uses a capacitor to create an out of phase lead coil until the rotating squirrel cages induces it's own or a copper coil creates a lag in a shaded pole motor. See above. As for imbalanced load I'm not at all sure but 15kW implies 62A at a power factor of one so yes there could be a problem at low power factors You've lost me there, I can see using a transformer on one phase can create a 90 degree lag which would create a non symmetric rotating field with the other two but two transformers? and my maths doesn't do the sums of sines any more and it's too late for me to go back to A level maths again.
  8. So you have 380-440V between then and 230-250V between each and earth? Theoretically you could stick a bigger 3ph motor wiring 2 of it's terminals with the incoming phases and each coil to earth and then once that is spinning draw 3ph of each terminal as the rotating squirrel cage will induce the third phase. Mind it is 50 years since I studied electrical engineering.
  9. I agree with your last point but not the first. In normal white and grey cast iron the sites where oxygen can get in are occupied by cementite,(iron carbide) and graphite. This is why you cannot cut cast iron with oxy-acetylene or oxy-propane cutters. It is also why you can often find old iron castings still sound but pitted when steel has rusted away in flakes. Stainless steel develops a thin layer of chromium oxide which prevents oxygen penetrating further, put it in an acid environment which strips away the chromium oxide and it corrodes. I have posted a picture in the past of a flue pipe made of 316 pinpricked with holes where burning damp coated wood had allowed an acid condensate to form in the flue.
  10. Yes they are cast iron but doesn't cast iron resist rusting better than steel? I had assumed it was the pads exposing fresh iron that meant surface rust happened quickly.
  11. Hi Roger Long time no see. It looks like your website fell foul of brexit
  12. caught two on the lampshade this evening and put them out
  13. Try TXM plant, we hired their road railers but of course mostly the mats were already in position. I think I might know where there are some discarded level crossing rubber mats.
  14. There's definitely a queen living at the back of my bookcase against the cold outside wall because I saw her fly there from the log basket.
  15. I'm fairly sanguine about nuclear energy but this business of committing future generations to managing the waste is why I wouldn't support it because we have built our riches and wealth on fossil fuels and there is no saying future generations are going to enjoy the standards we have had for the last 50 years. I actually believe it could have been done much better but it wasn't and there is already a terrible legacy. I have a reasonable chance of dying within the next five years but I do have grandchildren to consider.

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