Jump to content

Log in or register to remove this advert

openspaceman

Veteran Member
  • Posts

    9,699
  • Joined

  • Last visited

  • Days Won

    5

Everything posted by openspaceman

  1. I think this bluish orange is the area to aim for. As you say if you put a dry bit of softwood on it rapidly evolves offgas ( the results of heating the wood is pyrolysis which means splitting the wood components by heat). This offgas then burns in what is known as a diffuse flame, the oxygen enters the fuel rich gas from the outside, the oxygen then further splits away the hydrogen and burns as a flame but leaves the carbon particles glowing yellow in the flame until enough more oxygen diffuses into the flame and oxidises this carbon. This is where a jet of hot air aids turbulence. If enough oxygen cannot pass into the flame before it cools down (mostly by radiatingto a cool surface) the carbon particles reform to a mixture of sooty particles, some of the carbon atoms reform in the heat to tiny plates of graphene, a single layer of graphite, graphite resists oxidation so once formed these sooty particles tend to carry over into the flue. This is why it is important to keep the combustion chamber hot and with enough residence time for the flame to be able to burn out. My take on this by observing the glass window on my little Morso II, is that you really need to see all the flame within the box to cut soot. Even so I have noticed, as the firebox is small, if I put a dry piece of wood on top of hot coals the sudden evolution of offgas overwhelms the ability of the downwash secondary air and the excess air holes half way up the back of the firebox and I can see sooty smoke. This happens with birch and holly for some reason, of course we know birch has an oily bark but holly? The only way to avoid these yellow flames going up the flue and being quenched is to cut the logs smaller, and not to load above the level of the excess air holes, so less offgas is suddenly evolved and there is adequate air to burn it.. That is a bit of a challenge to me. The main thing is to keep the combustion hot enough with adequate air to burn the tars before they get the chance to enter the flue. Wood moisture is the biggest culprit for lowering the temperature in a modern insulated firebox.
  2. MOT type one is a size distribution/assortment. Round here it tends to be mendip limestone and as it is compacted it crushes down to fill the voids nicely, then you put a wear course on top. If you omit the wear course the traffic crushes it further and the rain washes out the fines. Tarmac planings tend to be 10% bitumen, 40% stone (often limestone here) and 50% sand. Once the bitumen degrades the sand tends to wash out. ECO type one seems to have a mixture of crushed concrete, brick and pebbles and seems to hold up better.
  3. It looks like good old fashioned keynsian economics, couple this with the decision to go ahead with HS2, renewable energy etc.and devaluation of the pound post the referendum the government will spend its way out of depression. Just let's hope UK Ltd. can pick up the baton and run with it without dropping it to China Tech or Trumptown.
  4. I thought that was for clay sites? The Plaisance I drove had been used for road crushing before I got to drive it and I was told this included incorporating lime AND/OR OPC
  5. Talk about thread drift. Anyway your post made me search again and quickly came up with this: "The Far East was where the Mosquito suffered its most difficult losses – not due to the enemy, but to the degradation of the early version of their glued wooden joints (using casein glue in an unsuitable climate) leading to structural failure – sometimes in the air. Early production aircraft which were in India and Burma were condemned on inspection, but later examples in which formaldehyde-based glue rather than the milk-protein based casein were used, were passed as fit to fly." The Wooden Wonder – The Mosquito WWW.TRIUMPHWORKS.CO.UK After its first flight on the 25th November, 1940, the de Havilland DH.98 Mosquito was immediately adopted as a... Which is much what my father said, though I had wrongly ascribed the glue failure to bugs or fungi rather than heat and moisture. He fitted radar to them in 44-45, he had not realised that the tide of war had gone in allied favour when he was sent out, he didn't get back till 46.
  6. We were advised to do this, for cutting wildfire charred trees, and soak them in oil first, a special oil used by dirt bikes was suggested. I tried it briefly but the mills didn't want the timber so we put a Cat 977 and powerfork through the lot and burnt it.
  7. My dad implied it was bugs eating the glue that was the problem rather than boring insects so they changed it to a non casein based glue. I never did find reference to this when I searched for details of their use in Burma.
  8. I've a pretty fair idea Oi, I didn't think we had met.
  9. Sez who? Mind mine is probably 40 years old and measures 8" across the top of the pocket and 8" deep in the pocket
  10. Respect mate, I can safely say I have never got my knee down and don't intend to try but I'm still happy riding.
  11. I noticed my Morso had much less draw than the Jotul 602 it replaced and I put it down to the more tortuous path the primary and secondary air take, especially the fact the flow over the glass is a downwash so it is running counter to heat rising and thus doen't really draw well until there is a good hot flow up the chimney.
  12. Wasn't the traditional method to build the base with heather bales?
  13. I have known a house where a newly installed aga or rayburn would not pass the draw test for the chimney, it was not lined and the flue exhausted directly to a 9" brick chimney. The house was centrally heated and there was an open fireplace in the sitting room and that chimney was some metres taller than the aga one in the kitchen extension. I surmised that the heat from the aga was not sufficient to overcome the cold air in the chimney exacerbated by the warm air exiting via the sitting room actually causing a downdraught at the aga. I never did get told the final outcome
  14. is your council so inflexible they couldn't allow you to be seconded to the parks department for a while?
  15. I didn't know whether to laugh, like or just await the incoming onslaught. Yes Harsh and unkind but with a fair amount of truth excepting the old bit.
  16. Sounds like a draught problem as the one downstairs has a longer chimney. Are they both running at the same time? Are both flues lined and insulated?
  17. I've no doubt the breweries get paid for it. Not including the word "grain" would have left "brewers" which would have been meaningless as brewers' grain is the term that was used for them when we fed them to cows, yes they would have contained vestiges of malt but it was the maltose that the brewer fermented to make the beer, so most of it would have been removed.
  18. Brewers grains, it's the spent mash rather than malt which is in the beer, cows loved it. I get my logs for no payment because they cost time and transport off a job. Once they get to the yard I don't get offered them.
  19. It's the same with the Dosko on the team I was helping with, I always ended up as the brash dragger chipper feeder, it does the job with care but it's frustrating when you have used a chipper that you can drop a piece in and just walk away. Also the fumes were becoming a problem with my breathing and the noise is an embarrassment in urban situations BUT it's better than nothing.
  20. Docklands Light Railway is driverless, the attendant just opens and closes doors, I've not been on it as I preferred to walk from Waterloo to Canary wharf.
  21. If you get a derisory offer is it worth selling? With the problems some have had with new machines why not keep it as a back up until you are confident you can manage without it.
  22. In the absence of knowing what program or website you use for reading e-mail I cannot be more specific I'm afraid
  23. Most email clients have filtering and you can filter on the field mailed-by:vps1.arbchat.co.uk to be whitelisted or simply have these emails go into a dedicated folder
  24. I've a feeling almost any paint will suffice, old household emulsion, oil paint etc. the freer the better but I have no empirical evidence so may well be wrong.
  25. That's a nice short butt, almost a shame to cut it TT. It's not likely an issue for the next month but, as RHewn has said, you want thinner softwood seasoned stickers. Also have the stickers strictly vertical above each other and I would have them in line with both ends and the ends painted (because by summer you don't want moisture loss from the ends to be much greater than overall moisture loss) and some heavy weights on the top (I am not a fan of straps).

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

Articles

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.