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David Mack

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Posts posted by David Mack

  1. 25 minutes ago, LadyG said:

    and because they seem unable to produce this statement of account, which is a simple document, it would acknowledge my payments, that is why I want it.

    But you know you have paid, and have bank statements showing those payments. It doesn't seem that they have disputed receiving any money, so why do you need the acknowledgement?

  2. 1 hour ago, Cananalmaps said:

    Smeaton's carefully considered and concise reports were a model for future engineers.  This one for the Trent & Mersey Canal proposal is a good example.  Interesting that there is no mention of a tunnel at Harecastle.

    Indeed. He refers specifically to a deep cutting across the summit. Presumably at a somewhat higher level than the tunnel was built.

  3. 13 hours ago, Stevebd said:

    We. Don't like the idea of a back boiler in 28 mm copper to 15 mm though a pump then back to 28 mm copper tube.

    Why not?

    If its a back boiler system it was probably intended to be gravity circulation with 28mm pipe to provide minimum resistance. My guess is it didn't actually circulate properly so was converted to pumped circulation. If that had intended from the start it would have used 15mm pipe throughout anyway.

    • Greenie 1
    • Happy 1
  4. 14 minutes ago, MtB said:

     

    We here seem to be assuming you want a 12Vdc pump though. If you actually want a 230Vac pump then pretty much any central heating circulating pump will do. You can fit them with 22mm or 28mm isolator valves but beware, they typically draw about 50W all the time they are running.

    And will require your inverter to be on.

  5. Belfast's hull was primed with Jotun Penguard HB 2 part epoxy primer, and the same was used internally for the bilges.

    If you are going to use part cans, the weight of each component you need is given at https://www.smlmarinepaints.co.uk/uploads/files/library/files/2 pack weights 0314.pdf. Get yourself a cheap set of digital kitchen scales to weigh out the 2 components - a fiver from Asda when I bought mine.

    Since your boat is already out of the water you would get the best out of a 2 pack epoxy paint system if you had the hull shot blasted first. It will cost, but it will be a better job and will save you days or weeks of running around with an angle grinder and wire brush.

  6. 3 hours ago, PeterScott said:

     

    It included the word artconsortiume. ...

     

    (Reverse-engineer it by replacing consortium by icl ...)

    I knew someone who submitted a draft document for a project in Liverpool, which was strongly based on a similar previous project they had done in Manchester. Unfortunately, the search-and-replace failed to substitute for the one misspelled instance of 'Manchester'. The Liverpool client was not amused!

  7. I think that warm moist air from the cabin can find its way past the plywood panels into the unheated area around the tank, and the water vapour will condense on the cold hull sides, deck plate and water tank. Condensation will not be obvious if you look when the outside temperature is relatively warm, but I bet its there if you look early in the morning or late in the evening.

    • Greenie 1
  8. 1 hour ago, PaulJ said:

    Not really. A corroded welded in fitting will only drip slightly to start increasing over time.

    You would hope the appearance or smell over time of damp would be noticed and give warning of the problem.

    This plastic fitting was screwed onto a threaded pipe welded to the hull. It was all working perfectly, with no dripping, damp or smell, until I came to remove the wash basin and the heavily corroded pipe came off in my hand. The boat had been fitted out about 25 years earlier. But fortunately it was way above the water line.

     

  9. 56 minutes ago, davidwheeler said:

    they were  really just internal paddle wheels

    But simple paddle wheels of constant diameter operating in a cylindrical casing, entirely above the bottom of the boat, would just churn up a lot of water but not produce much propulsive force. The key to the Hotchkiss cone must be that water is drawn in at the small end, and the paddle wheel (which I see has slightly curved blades) accelerates the water both along the cone towards the biģ end and out to the larger diameter. Thus water is drawn in at the small end and out at the large end, but using a single hull opening rather than separate intake and outlet openings, as with other water jet propulsion systems. I guess they were normally installed as handed pairs to cancel out any lateral forces.

    Simple devices and suitable for shallow water, but I wonder how the overall efficiency compares with a screw propeller outside the hull.

    • Greenie 1
  10. When the decision was made that for rebuilding of Notre Dame after the fire, the new roof would be made of timber, similar to that which was destroyed, they had to source timber from all over France to find enough oak trees of the right size. I wonder what that has done to the price of oak in the country.

  11. 1 hour ago, blackrose said:

    Is 3mm thick enough to get enough threads in to make it secure and watertight? I honestly don't know but I'd hate to think about some clumsy oaf with steel toecap boots accidently kicking the fitting and emptying the contents of the skin tank.

    Well a welded on socket would certainly be better, but if the OP doesn't have access to welding equipment (or the skill to do a proper job of it), then drilling and tapping the tank may be the only DIY option. A simple plug would be less vulnerable to the steel toecapped oaf than a screw in drain cock, and would need to be screwed in enough to seal and no more - gorilla muscles on an oversize spanner could indeed strip the thread.

  12. The footnote to the report indicates that several reservoirs are being held at lower levels for engineering reasons. The big drop in the Shroppie/S&W group took place between December and January (although no reason is given in the January report), and the level rose by 3.6% from January to February. Since this section receives water throughout the year from Wolverhampton's sewage treatment works and from the BCN via the Wolverhampton flight, I suspect the low holding is of less concern than it might be elsewhere.

    The latest report gives the position at mid February, so the March report will be out soon, and will give a better picture of the water supply available at the beginning of the 'boating season'.

  13. 55 minutes ago, robtheplod said:

    what is the normal procedure on the Severn locks between Stourport and Droitwich outside of Winter closure... do you honk?? :)

    In my experience, if you arrive during manned hours the lock keeper will see you approaching, and if there are no boats using the lock he/she will start opening the gates or turning the lock before you arrive. If the traffic lights go green you can just motor straight into the lock, otherwise its usually easier just to hang around in midstream (current/flow/proximity of weir permitting) for a few minutes while the lock is readied.

    I can only recall one occasion when we actually had to moor up and go and find the keeper to see what was happening.

    • Greenie 1
  14. 48 minutes ago, Tony Brooks said:

    I think t would need a spigot welding in if you want to use a valve, but I think a simple plug could use a thread tapped into the tank skin. If welding is to be done then in order to weld the bottom of the spigot it would have to be clear of the baseplate, s that provides a sediment trap.

    I don't see why you couldn't drill and tap a skin tank to take a drain cock like this as long as the steel is at least 3mm thick.

    1-2in-bsp-brass-drain-cock-type-a-to-bs-

    But you would need room to rotate the fitting when screwing it in, so the drain would inevitably be a little above the bottom of the tank. 

    A simple threaded plug could be fitted as close to the bottom of the tank as you could drill and tap.

    1-2in-plain-hollow-plug-black_min_6446_P

  15. Normally skin tanks are mounted vertically on the side of the swim and all you have to do is loosen the bottom hose connection and the tank will empty into the bilges.

    Is yours on the bottom plate? If so you may have to pump it out with something like a Pela pump, or perhaps a wet and dry vac with a nozzle small enough to pass through the hose fitting.

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