I meant to ask this question last week when I asked about firebox welding/repair ect. My question is, is there a "working" reason why most people choose to continue to thread staybolts rather then welding them. Was told that the Laona engines firebox was repaired with welded stays, but this is the only one that I know of. I do know that there must be others as well, so what is the reason most stay with the threaded stays. I was also told that flush welded stays had a tendancy to break more do to stress then the ones that were extended slightly. Any truth to this? Many thanks in advance for the "knowledgeable" taking time to answer my many questions on boiler repair and welding proceedures. Regards, John.

springfield@tds.net

John,

I am by no means an "expert" (yet), but I do know quite a bit....
To my understanding, the reason why most stays (non-flexible, of course) are threaded and peened over is due to ease of later removal and inspection. When you go to remove a stay that has been welded, you pretty much have to remove or cut out much of the welded area, making it extremely hard to re-insert a stay of the same size into the same hole. When you thread the stay however, you can cut through the on the central/longitudinal portion of the stay (through the side of the telltale), and back the upper part (which has just been removed from the bottom by cutting) out with a chisel. This method provides you with a means (when conducted carefully) to save the original threaded hole that the stay was in.

Anyone who knows more please feel free to correct me!

Hope this helps!

Dave Haring
-W&W Shop Crew/Trainman
-R&T Shay R.R. Fireman/Conductor

> I meant to ask this question last week when
> I asked about firebox welding/repair ect. My
> question is, is there a "working"
> reason why most people choose to continue to
> thread staybolts rather then welding them.
> Was told that the Laona engines firebox was
> repaired with welded stays, but this is the
> only one that I know of. I do know that
> there must be others as well, so what is the
> reason most stay with the threaded stays. I
> was also told that flush welded stays had a
> tendancy to break more do to stress then the
> ones that were extended slightly. Any truth
> to this? Many thanks in advance for the
> "knowledgeable" taking time to
> answer my many questions on boiler repair
> and welding proceedures. Regards, John.


The Historic Wilmington and Western Steam Railroad
SteamTrain84@aol.com

> John,

> I am by no means an "expert"
> (yet), but I do know quite a bit....
> To my understanding, the reason why most
> stays (non-flexible, of course) are threaded
> and peened over is due to ease of later
> removal and inspection. When you go to
> remove a stay that has been welded, you
> pretty much have to remove or cut out much
> of the welded area, making it extremely hard
> to re-insert a stay of the same size into
> the same hole. When you thread the stay
> however, you can cut through the on the
> central/longitudinal portion of the stay
> (through the side of the telltale), and back
> the upper part (which has just been removed
> from the bottom by cutting) out with a
> chisel. This method provides you with a
> means (when conducted carefully) to save the
> original threaded hole that the stay was in.

> Anyone who knows more please feel free to
> correct me!

> Hope this helps!

> Dave Haring
> -W&W Shop Crew/Trainman
> -R&T Shay R.R. Fireman/Conductor
Thanks for the reply Dave. I have been told that reason before and while it may be a valid reason to some, it didn't really make all that much sense to me. Some times I can be rather dense too. I guess by looking at it from my vantage point I can't see the logic, but then again I think like a welder and don't see any reason not to weld. Of course that is why I am asking. I was given this reasoning as well as "historical integrity", which I can relate too on one hand, but if you want to keep running old boilers you may have to update 100 years of technology and apply it. I realize that staybolts work just fine the theaded way, but am referring to updating 1906 technology so we can keep running steam in the future. I do appreciate the reply, regards John. PS I have seen some "saved" staybolt holes, and I wouldn't really feel that good about screwing in a new staybolt. The threads may look all there, but I think those threads may not be what they used to be as far as strength goes. Guess I am being a "devils advocate" here!

springfield@tds.net

> I meant to ask this question last week when
> I asked about firebox welding/repair ect. My
> question is, is there a "working"
> reason why most people choose to continue to
> thread staybolts rather then welding them.
> Was told that the Laona engines firebox was
> repaired with welded stays, but this is the
> only one that I know of. I do know that
> there must be others as well, so what is the
> reason most stay with the threaded stays. I
> was also told that flush welded stays had a
> tendancy to break more do to stress then the
> ones that were extended slightly. Any truth
> to this? Many thanks in advance for the
> "knowledgeable" taking time to
> answer my many questions on boiler repair
> and welding proceedures. Regards, John.
the threaded stays are easier for most people to change themselfs. If you come under the state you most likly need a code shop to do it. But you could put your own threaded ones in. As for my self I don't think one way is all that better than the other. I have seen and done both. regards bb

The threaded bolts are much eaiser to change but there is nore to it than that. The dynamics of welded bolts are different that those of threaded bolts and if you mix the two the threaded bolts teld to loose and break. Most repairs are done "in kind" with the same materials and same methods.

To put it in automotive terms your shouldn't put a Chevy head on a Ford block.



pfdx@aol.com