The Home Machinist!

Hi Tim - the through stays are 1/4" NPT Sch 80 seamless, SA106-B.
One thing I learned long ago - tack, then weld one end, leaving the other free to expand.
Unless of course, you want it to assume a gentle curve!

Somewhere I remember hearing somebody say, "You get what you pay for".
What a beautiful product!

It's almost a shame to eventually hide that thing under lagging and a sheet metal jacket. It really should go on a pedestal in the Metropolitan Museum of Art.

Thanks for the info Marty.

We put the tubes in today.

Marty, That's a Milwaukee wrist breaker drill/driver with a brand new anti wrist breaker (unhanded) handle.

Beautiful, beautiful work!

BC

Here are links to the YouTube videos of rolling the tubes.
https://youtu.be/4HtbHUnFpb8
https://youtu.be/DW1pszsFcEk

Hi Marty,

On the photo from 12/8 showing the firebox tubesheet to crownsheet joint, about what size gap did you guys start with? Also, is it cheating to tack up and then gouge from the same side, finally going back to gouge out and finish weld the spots with tacks?

-John

Marty:
I am currently laying out my 10 wheeler boiler ( I guess you know that), So I am soaking up as much information as I can. I see that you put quite a proud countersink for your stays. I assume for a full penetration. Is that necessary beyond a simple fillet? Is there an advantage that I don't see?
And, we all thank you so much for sharing your information here. It really helps us understand what is going on inside the boiler and firebox, what to expect and how to better (safely) take care of our investments.
Scotty

That's a great question in regards to the stays. I'm hoping to reap a benefit from Marty's response, but I'd like to comment, in the hopes that I understand the purpose of the large countersink.

Going out on a limb, I'd suggest that the purpose is to ensure a 100% weld. Any area that is open would permit water to create corrosion, and getting full penetration without proper relief isn't easy. The large countersink allows for a weld through to the opposite side, resulting in the stays being a part of the body, with no seam to collect water. Now lets see what Marty has to say.

H

Harold_V wrote:That's a great question in regards to the stays. I'm hoping to reap a benefit from Marty's response, but I'd like to comment, in the hopes that I understand the purpose of the large countersink.

Going out on a limb, I'd suggest that the purpose is to ensure a 100% weld. Any area that is open would permit water to create corrosion, and getting full penetration without proper relief isn't easy. The large countersink allows for a weld through to the opposite side, resulting in the stays being a part of the body, with no seam to collect water. Now lets see what Marty has to say.

H

Exactly right, Harold.
Another reason is that you should not weld over the end of the stay. You leave enough of the end exposed so you can tell that it is, indeed, a stay - not just a glob of weld.
The large prep makes it easier to weld from the side.

Marty_Knox wrote:Another reason is that you should not weld over the end of the stay. You leave enough of the end exposed so you can tell that it is, indeed, a stay - not just a glob of weld.

Thanks, Marty. That thought didn't occur to me.

H