Best Of SP&S 4-6-2 #626 Project

[mmagliaro]

Hello again everyone.

This installment covers a variety of construction topics:
- Making the firebox
- Joining the cab, firebox, and boiler together into a shell
- Mounting and aligning the shell on the frame

The photos should all include their own captions to explain what's going on. 

There are a lot of photos in all these steps, so I'll get this up there in several posts.

[mmagliaro]

On to the firebox, cab, and shell mount...

[Lemosteam]

Looking great Max!

[chicken45]

JB Weld is one of the greatest inventions ever. It's machinable!

[robert3985]

Max, totally fascinating!

[superturbine]

Looking really good Max,

Just curious, The screw, I am sure you have measured it out, but it appears to me to be located under the steam dome.  Screw accessed through the steam dome?  Also, I notice a slight boiler diameter change going from the 3rd boiler band to the fire box.  What's your thoughts

-Jason

[mmagliaro]

Looking really good Max,

Just curious, The screw, I am sure you have measured it out, but it appears to me to be located under the steam dome.  Screw accessed through the steam dome?  Also, I notice a slight boiler diameter change going from the 3rd boiler band to the fire box.  What's your thoughts

-Jason

Hi Jason, thanks (and thank you to everyone!) ...
Yes, the screw comes up right where the dome will be.  That's how I plan to hide it.

The boiler diameter is a puzzler.  I have looked a numerous photos of the real engine.  In the prototype photo I showed at the start of this thread, the boiler does appear to have a subtle taper on the section just in front of the firebox.  But the prototype drawings show
no such change in diameter.  So it must be a slight difference in the jacketing thickness.   I have also looked at some
photos of HO brass versions of this engine, and it is hard to even see that there is a taper. 
Overall, the difference would be, perhaps, the wrapping of even less than a .005"
sheet of styrene.  So what I'm thinking is that I'll wrap a strip of .005" on there, about an inch wide,
and clamp it and use a band of sandpaper, running it back and forth around the boiler,  to take some of the .005"
off and carefully taper it a little, to transition it to the next boiler stage, which will be my bare tube that you see in
the current photos.   I used a similar approach on my NYC Dreyfuss Hudson.  I transitioned that one with a "wrapping"
of JB Weld between boiler courses, and then wrapped sandaper and ran it back and forth until the JB Weld "transition"
area was smooth and tapered.

This one will be easier, I think, because the amount of change will be so slight.... I hope!

[chessie system fan]

Max, what size styrene tubing are you using for the boiler?

[mmagliaro]

Max, what size styrene tubing are you using for the boiler?

It is 1/2".  That works out to being a little big, (80" diameter), by 2-4 inches depending on where you are on the boiler.
But that is hardly noticeable in N Scale.

[Chris333]

I especially like the jigs for the walkways. I never though of doing that.

[mmagliaro]

I especially like the jigs for the walkways. I never though of doing that.

Ha!  Me either, and I can't imagine why!  It's so obvious, and walkways are a pain to get straight.
As you can see from this project, I've been "jig happy" this time.   Template to shape the cab roof, jigs
to spot the walkways and boiler height, jigs to support the cab so the whole thing isn't skewed around
on the  frame while I made that little keyed notch on the front.  It just makes it so much easier to get things straight.

[mmagliaro]

As per Jason's observation, I wrapped a piece of .005" styrene around the first part of the boiler just after the firebox, and commenced sanding a gentle taper into that area with bands of sandpaper, starting with 150 grit, then 400, and the 800.
I also got the boiler bands on.

I hit the shell with a quick spray of black because it's very hard to see flaws against all that white styrene.
Next, I will get out the sanding bands again and smooth the rounded upper corners of the firebox.  They need
to be smoothed, rounded, and pulled inward some more.  But otherwise, I think the boiler shape is okay now.

I actually sanded some more after applying the boiler bands, deliberately sanding the bands themselves to thin them down.
Even .005" is just too thick.  The bands on this engine are very very flat and wide. 

Oh, and that one very narrow band just in front of the firebox is really there on the drawings and photos.
I am not sure if it's supposed to be a regular band with just part of it peeking out from under the firebox seam,
or a special band.

[chicken45]

Awesome!

[mmagliaro]

Awesome!

Thanks, man.  But the top edges of that firebox ain't lookin' so awesome right now.  That is really starting to bug me.
I know what I'll be doing late tonight. 

[superturbine]

Lookin really good Maximus!! 

The boiler band and boiler diameter change blend really well.

Jason