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. n.b. There is a list of my first 800 posts in my post of 17 June 2021, titled "800 Posts"

Trevithick Dredger Engine-2 steps forward, 1 step back.

A few posts back I reported how I very cleverly silver soldered together some “sliced bread” bits of brass and bronze, because I did not have big enough material.

Then I spent a day machining the outlines, drilling the holes and finishing the parts.

Today I silver soldered the parts to the Trevithick boiler.  The joins in the material were so good they were invisible, and the fact that the joins were there did not enter my brain.

And this was the outcome.

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Before

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After

The beautiful silver soldered join melted as I attempted to silver solder the part to the boiler.  It has made the part unusable.

I will go through the exercise again, but next time I will bronze braze the join.  Bronze will not melt or let go with silver soldering temperatures.

I will try to not make this mistake again.  I try to not make the same mistake more than 3 or 4 times.

Trevithick Dredger Engine- Supports

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These are the boiler supports for th Trevithick Dredger Engine, which need a little more finishing.

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As you can see my CNC mill is working nicely.  The slow feed rate is because the brass is just super glued to the mounting base and I did not want to risk it coming adrift.

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The CNC milled parts.  The brass is 7.5mm thick.

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And this was cut out from the edge silver soldered brass bread slices.

And I have also been working on the 6″ vertical boiler.  The brazing with silver solder is almost finished.  I have been redoing some of the joins, and can now get the pressure up to 200psi.  There are 101 soldered joins in the construction (so far), so I am not too upset that a few of them were not perfect and required a redo.  SWMBO was wondering about the bills from the industrial gas supplier.  I have used several fills of oxygen.  Totally abandoned acetylene and using propane now.  It delivers more heat (at a slightly lower temperature), and much less costly.

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