Jubilee boiler stays

I am finishing a boiler for the Martin Evans 3.5" gauge Jubilee tank.

The firebox is so narrow I am not sure how to complete the stays. ME says to soft solder them, but on previous boilers my club inspector have always frowned when soft solder is mentioned. If it is to be silver solder how do I get enough heat for the job.

i should mention it is a belpair shape, and the back head is already on.

has anyone out there made one of these (or similar) and if so how is it done please?

many thanks

hi john,

you dont say what equipment you have either propane or oxy-acetylene or oxy-propane.

ive done quite a few loco boilers copper silver soldered throughout with propane (see one of my albums), but the inner firebox doorplate has to be left off to silver solder the stays on the inside of the firebox. you can forget cyclone burners in such situations. it would be possible to do with oxy-acetylene or oxy-propane but it isnt an easy job with the inner firebox doorplate already silver soldered in position on a small boiler such as your's.

this rather begs the question if you knew your boiler inspector doesnt like comsol caulked stays on a new boiler why did you silver solder the inner firebox doorplate and backhead into position? i discuss plus show for examination all stages of boiler construction with my club boiler inspector.

that having been said, the current UK regs allow comsol caulked firebox stays, and i think your boiler inspector is being quite unreasonable in not following the current code. in fact i would never advise a beginner to do anything other than comsol the firebox stays, as you need to be pretty experienced to do them ok with silver solder.

perhaps change clubs and seek a second opinion?

obviously comsoled stays need to be threaded, and nutted on the inside of the firebox.

cheers,

julian

Thanks Julienne. That's helpful.

I have two propane torches with a range of a Sievert burners.

what material would you suggest for the threaded stays? Is it Gunmetal?

john

hi john,

the drawings probably specify gunmetal but i think gunmetal is totally unsuitable for stays. copper or hard drawn phos bronze would be much better.

cheers,

julian

Hi John,

As Julian says, you will be really struggling to silver solder stays now the backhead is fitted. Access will be difficult even with oxy acetylne/propane. There is nothing in the boiler regs that says you cannot use Comsol in a boiler but unfortunately some boiler inspectors make their own rules.

You might find the construction of my Helen Long boiler of interest as that uses threaded and nutted stays:

**LINK**

I theaded copper rivets for the stays which wasn't difficult to do, much to my surprise. The heads are actually silver soldered outside as that was easy to do but the firebox ends have brass nuts fitted and then caulked with Comsol.

You do have to keep a watchful eye on the water level but it would have to get pretty low to melt the solder.

John

Not withstanding John & Julian's comments, I have found it more difficult to apply comsol than SS, but then I do use oxy and its difficult with low temp solder. If you do as advised above, just remember to SS the outside before you comsol the inside - or it will all melt and fall off! Im not advising this, but way back I used copper nails on a 31/2 boiler, the head soft soldered on the inside. Made a very neat job and was easier to get the solder to melt due to the head size - surely frowned upon today but you never know!

My thanks to all for this advice. Looks like threaded copper stays, silver soldered outside first ( !), nutted and comsol on the inside. This should be pretty straightforward with my cyclone burner.

Julian - apologies for calling you Julienne - not intended - it's this dam ipad that keeps finishing words for me!

really grateful for all your comments.

john

I am assuming that you have a running Jubilee chassis.

How did you overcome the crosshead clashing with the coupling rod ?

The bottom of the expansion link clashing with the connecting rod ?

The return crank being far too 'out' to avoid a cranked eccentric rod ?

I've triple checked dimensions from the drawings and they do happen !

Your web site is very informative, thanks.

But one question: on Helen's boiler why did you not thread just the ends of the rivets? The end beneath the head does not need to be threaded as it is held strongly enough in place by the head and by the solder/braze.

Rob

Edited By robert mort on 15/11/2014 11:01:20

Hi, going to start my first loco 31/2" Jubilee. Just a couple of questions.

Will the latest drawings have been modified from originals?

Has anybody any answers to J. Hancock,s post

Derek

hi Derek,

i am not aware that the drawings have been 'updated'.

yes, this matter has been discussed in some detail recently on the following forum and thread

**LINK**

cheers,

julian

Hi Derek,

The LINK certainly walks you through several possible ways of ' making it work' after all the mistakes have been made ! I certainly had to adopt a few to make mine rotate without hitting things in all sorts of places.

It seems ' corrected' drawings do not exist , even today.

What we know.

The cylinder castings should never have had that ' packing' dimension machined off in the first place !

Think of a better way to fit those' support cheeks' either side of the valve rod as it exits the steam chest.

Re-drawing the whole 'layout' on squared paper , using the drawing dimensions , will show you exactly how

'impossible' it is to work ! And is the first step to see where all the 'corrections' need to be made.

As shown , changes can also be necessary to the running boards.

Make the brake assembly as drawn and you will never drop the ashpan !

Enough to get started on ?

Lovely locomotive though,well worth the effort to make.

Hi guys

Thanks for your response, checked out the links and realise there is loads of info out there for newbie

loco builders

First time in a forum so hope I can call on you all if I have problems

cheers

Derek

Incidentally, I've found 3.5mm, 30mm (or longer) copper nails to be excellent and cheap for stays, particularly crown stays: see **LINK**