Crown stays, superheat and bushes

[Deleted]

Hi all,
Regarding crown stays, on the one hand LBSC didn't like rods due to waisting (or wasting?) away and Martin Evans similarly seemed to prefer girder stays, whereas Nick Feast in the ongoing Q1 in ME has used P.Bronze rods as it helped him set the firebox wrapper gap.
On superheat, specifically, I have G.A. builders drawings for a successful locomotive that has no superheater. What are the group's thoughts on being prototypically correct and omitting this on a model in our scales?
Finally, if there is a choice between having a central screw thread to fix to a larger boiler bush such as for the regulator in the tube plate, or simply 4 radial screws, what do people think?
Thanks
Dave

[Shawki Shlemon]

I use hard drawn copper rod to make crown stays and form a head on one side . I generally use super heaters but it is one of those things that people argue about its need , I think they help . As for the the last point I agree with Paul radial screws are better in my opinion .

[Deleted]

Thanks for your replies. What is your preference for fixing the top end of the stays? If you use a blind nipple or thin profile nut, followed by silver solder on both top and bottom ends, you get a penetration of the stay end into the cladding over the firebox. I have seen hollow depressions purposely formed at the heads to get round this, but I'm not so sure if this is ideal.
Many thanks
Dave

[steam4ian]

G'day Dave

Regarding crown stays the AMBSC Code seems to come down on the side of rod stays as opposed to girder stays. IMHO I think rod stays would be easier because you can fit them progressively. Shawki answered one of my questions by advising the use of temporary threaded rods during soldering up to hold the parts in their correct relationships; the rods had divided spacers such that the spacers could fall out of the boiler when the rod is removed.

Regarding super heating I am in the process of making the same choice at the moment. See the topic in the General section.
It would seem that little boilers need all the help they can get to deliver dry hot steam and lessen wastage in the cylinders due to condensation.
One thing that gets overlooked is that we seldom run with the regulator fully open so there will be some superheat due to wire drawing at the regulator.

My decision is being guided by the need to lower the firebox crown to get sufficient water and steam space and still get enough tubes. The old boiler inherently delivered wet (very wet) steam which needed superheating. If I can get more steam space I will get drier steam with less need for superheat.

Opinion at my club seems to favour superheating.

Regards
Ian