johnsmachines

machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment. I read every comment and respond to most.

Tag: firehole door

6″ Vertical Boiler. Finishing the firedoor

The doors on this boiler have consumed more time and energy than I expected.

Partly because the firedoor has a vent, has a heat shield, is oval shaped, and is mounted on a curved surface which will get very hot in use.

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It is still not quite finished, needing a catch and a latch.  There is a spring which pushes the vent against the door.  And a heat shield which needed a few shaping processes to make sure that it did not foul the firehole.  The heatshield is supposed to be stainless steel, but the copper cutout left over from when the firehole was cut in the wrapper, seemed ideal for the job.  The central shaft is stainless steel, threaded M4 at back and M3 through the door.

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I intend to use propane as the main fuel for the boiler, but I have constructed the firebox so it could use coal as an alternative.  This is the ash pan opening.  Constructed from 1.4mm brass, and silver soldering the join.  Pretty neat hey!  I have made the door and hinges, and will hang the door next session.  I will replace those cap screws with something more suitable.

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The hinges are quite small.  3mm wide, and when trimmed will be about 18mm long.  To make them I drilled a 1.5mm hole in a piece of brass rod, silver soldered the rod to some 1.3mm sheet brass, then bandsawed- cut the piece into separate hinges.  Since that pic was taken I have milled the width to 3mm, and trimmed the lengths.  I dropped one hinge, and spent a fruitless hour trying to find it.  Fortunately I had made a spare, but I cannot aford to lose another.  The hinges will be riveted to the door and the ashpan surround.

Two steps forward one step back again!

I had a whole day to myself, in the workshop.  SWMBO was happy painting or something, and the kids did not need us to baby sit the grandchildren.  So, let’s make the 6″ boiler fire door and ash pan door.

But first, I silver soldered the 4 joins on the super heater, and all went well.

The firehole is oval shaped, and the plans call for a rectangular door.  So I spent some time planning the machining for the rectangular door boxed section.  Then I thought … hang on…. this oval is really nice… why am I hiding it behind a rectangle ?

So back to the computer, and I worked out a method to make an oval door.  A bit like a hobbit door, with an adjustable vent.

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And here I am, machining it with a 2mm cutter.  In 1mm deep bites.  That brass is 4mm thick.

And I made a bracket to complete the hinge….

Drilled the holes for the 1.5mm pin…..

And the f*****g drill bit broke!!!!

I could not get it out.  It was a cobalt bit, and all of my methods for digging out broken bits were tried, taking a couple of hours, and failed.

So I reshaped the hinge end of the door..

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and I will silver solder a hinge end on tomorrow.