Building Kozo's New Shay locomotive

[crueby]

It sounds as though you are still making some good progress Crueby, and I have no doubt you will track down those last few pesky leaks and get them fixed.

Bill

Yup, still getting better, current leaks dont show till higher pressure, so I take that as good sign. Given the winter weather, am moving on to other parts during cold spells. That should keep the momentum going!

[Stuart]

Small weeps not spurts often take up on the first firing
Your tests done so far prove the boiler is safe but damp , just like our new born
Take care with repeated tests and bring the pressure up in increment due to the copper being fully soft at this stage .


I know it's not that time of year but do not ever test a boiler in the hot sunshine in summer , I have seen a boiler pumped up to twice its working pressure valued off and pump removed they then when inside for a beer to celebrate the success , on returning to the boiler it was like a balloon totally trashed , the reason the heat from the sun had expanded the water the pressure went sky high result boiler K for no good

If you followed not know what the K is for its where you take a a horse when it's dead here in the UK

Nice work on your first boiler they are not easy as some early plans have errors

Stuart

[crueby]

Stuart, good tip on the sun heating. Not a problem on this one right now, it would more likely freeze and burst this time of year! With use, and the expansion and contractions, is that enough for the copper to re work harden again? I was curious about that during assembly.

[Stuart]

Yes the stress of use heat/cool cycle will put the copper back to is normal state.
When a boiler is first made its like putty and may well fall below the stress level , mainly the fire flues and super heater flue my collapse that's why you bring up the pressure in stages and relax it before going for the two time swp.

Note also is very very rare for a copper silver soldered boiler to explode steel is another story .
In practical terms if the safety valve fails shut and the pressure goes up two things will happen one the gauge glass will break either from the pressure or more likely the backhead bending thus glass is broken . The othe failure mode is collapse of the flues this will stop the boiler steaming

Yes the boiler will be a mess but no bangs , no doubt someone will say other wise

The gage glass rupture is a failure mode and they should have a cage over them , imagine trying to shut off the blower with the cab full of steam
It is a fact that a boiler will hold steam but leak water when cold

Stuart
Yes I am guilty of trying for a perfect cold test but the initial test is for the structure of it

[daveb]

Hi all
Can't believe that I never found this site until now.  I have been building Kozos new shay for six years, not quite as fast as crueby although I am a little ahead.  Currently testing the engine out on air.  Having problems getting it to run on no load pressure of 10 Lbs.  It started running at 45 and its down to 25 now.  The engine is very tight and don't know if the cause is binding somewhere or the piston rings are to tight.
 
I can relate to the problems with the boiler.  I ended up doing a second boiler after I could not get the staybolts on the first one to seal.  I'd try to seal one and two others would start leaking.  With the second boiler my soldering skills were a lot better resulting in a better boiler which tested out to holding 175 lbs for 15 minutes.

I also can relate to your weather.  We live in Bow NH and were just without power for 2 days after 15" of heavy wet snow.  I do all my soldering outside and its not fun in the cold.
I'll try to attach a couple of pictures.  Its great to know someone else is building the new shay


 Daveb

[smfr]

Have you guys seen Ed Hume's Shay construction? https://www.flickr.com/photos/edhume3/sets/72157614192042835

Stunning!

Simon

[crueby]

Have you guys seen Ed Hume's Shay construction? https://www.flickr.com/photos/edhume3/sets/72157614192042835

Stunning!

Simon

Wow, that is beautiful work!

[crueby]

Hi Daveb,

When I am looking for binding in an engine, sometimes it helps to disconnect all but one conrod and valve at a time, and turn by hand. Can usually feel differences in resistance and narrow it down that way. Often its something like a slight misalignment. Just running it for a while can help. Running down around 10 is pretty good on small pistons. Picture looks good!

Chris

[crueby]

...  that's why you bring up the pressure in stages and relax it before going for the two time swp.

Did not know that one - thanks for the tip!!

It is a fact that a boiler will hold steam but leak water when cold

Stuart

Does that mean I dont need to be too concerned about the filed off assembly screw that just barely seeps a drop over a long time? If it is below the water fill level, will it still leak there when hot? Or does the metal expansion seal it up? I have been striving for zero leaks/seeps - if I can get there will be very happy for first attempt. Worst cases: either make another attempt, or keep it as a display/air-runner. Best case: all works. Either way, great project, learning a TON doing it.

[Stuart]

Water has disolved salts minerals that will stop the weeps

Note some people use distileled water , but that is corosive and will try to rebalance itself and leach from your boiler shell

Stuart

[b.lindsey]

Thanks for that link Simon. He did a fine job of documenting his build and with very nice results too!!

Bill

[b.lindsey]

Daveb,

When you have a chance it would be good to post an introduction in the introduction section so that we can welcome you properly to the forum. Meanwhile, nice work on your Shay and welcome to MEM.

Bill

[crueby]

Okay, back in the shop again! While waiting for the next batch of warm weather to arrive to do more boiler soldering work (we usually get a couple warm days every week or two this time of year, good thing too, or the snow would get really deep by end of winter seeing how we get anywhere from 60 to 160 inches a year!), I am going to skip ahead a chapter or so in the book and work on a simple/fun section, the cab and tender. The cab pieces are just soft soldered, so can do that work indoors. The few bits that are hard soldered are small, can use the little butane torch for those.

Started out with cutting the sheet brass for the roof/sides of the cab. The window openings get cut later on after the frames are in place, so for now just the outlines are cut.

Then, cut the brass bar stock for the edging pieces, and milled the ends to square them up and take them to final length.

Last photo shows these pieces laid out in place, ready to drill/tap for some small screws to hold them for soldering. Also, there are mounting holes to be drilled in them. Will get to that part later today probably. Got to get up to the range and get my bow sighted in before the winter leagues start, so may not get to soldering these pieces till tomorrow.... Nice to be back fabricating again - these pieces will change the look of the model really fast.

[Marinus]

That looks great. The cad would be quite sturdy, with those brass bars.
How did you cut the brass sheet?

[Roger B]

Looking good, as ever    We have snow forecast for this weekend so hot work/running engines may be curtailed for a while