Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: hammer on September 18, 2013, 04:39:25 pm
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Having built a paddle steamer. Can be seen on Paddleducks site under Duke of Devonshire. I am now making another boiler for her, with the lessons learned from the first 2. The present one not certified. So I am running electric at the moment. A low centre of gravity is required in a shallow draft boat. Being given some 2.5" tube I hit on the idea of a twin system. 2 burners off the same tank cold not be balanced, so each has a (home made) regulator fitted. Almost ready for the pressure test.
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RGY.... as mentioned/questioned on PD's....is this bronze brazing or silver soldering?.........certainly a substantial amount of filler material
Will be interesting to hear what the boiler inspector says....or if he have experience in the brazing process?.....Derek
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Derek. Further to the answer on P.D.s There looks a lot of filler but that is the beauty of brazing you can fill a hole. but not in this case. See the drawing below. Number 1 is is used to working with lines holding 100 bar plus :o so he likes plenty of cover. The inspector :police: had seen the fit before brazing. I could paint it black but it won't be seen inside the lagging. {-) Geoff
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Showing some progress. Made and fitted a 8mm sight gauge, as opposed to 5mm used previously, in the hope for more reliable readings. Also in the photo blow down & clack valves.
Had trouble with with the burner flame turning yellow, when the ceramic glowed red. Now the material has hardened flame stays blue. Informed there where impurities in the ceramic. The 2 regulators note I threaded the wrong half with the second, only spoilt the looks. The steam take off and pressure gauge now fixed ether side of the safety valve bush.
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Making the case, gallon cans made of tin plate are hard to find, but I still have 2. The end & base are thicker from an old DVD player. Wedge the thin sides in position with wood, cut holes to fit over fire tubes fit the plate in place, draw around the case, cut out 10mm outside the line. Bend the 10mm edges inward drill and tap in place. Same with the other end using the bushes this time. After fitting take apart and enlarge the holes so the fire tubes & bushes don't touch the case. I will use soldering mat as the insulation.
The new fitting on the spare bush is the water level overflow so I am not relying on the sight glass. Will be removing the safety valve to fill quickly with hot water from a Thermos, save on gas.
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Finished casing & made internal manifold. This will help heat the stem drum, and keep the case from getting two hot.
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The flue. The case in with the electric only takes 10 minutes just 4 screws.
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Put the boiler together so I won't lose an bits, as I have other work for some time. No wood on the out side Derek.
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Certainly getting there, would be intrested to see how it steams. Keep up the good work. :-))
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How did the pressure test go? :-)
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Phil & Martin. As I said the boiler will be on hold for a bit. I have pressure tested myself, but have to wait for the club tester for the official certificate. As for the steaming capability, if it matches my previous boiler it will be fast. The old boiler 2.5+7inches+2 with 22mm fire tubes with 3/16 cross tubes +9 in each. The new boiler 2.5+6inc +2 with 28mm fire tubes with 1/4 cross tubes +9. That is why I have made a safety valve with a 1/4" ball.
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Well no one has said anything about the syphon fitted to the pressure gauge!! Mounted flat and useless, as in the 2 photos above. Now fitted correctly and visible with the superstructure in position.
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Nothing wrong with the face of the pressure gauge being horizontal providing the syphon tube is vertical and below the gauge to allow for a water lock.
Regards Ian.
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Managed a little play, striped the boiler stuck the solder mat insulation. Two layers over the flue manifold. The manifold sealed to the boiler with fire cement, to prevent fumes leaking into the casing. Glue will withstand 800c plus
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That arrow.