Rolling a tapered boiler

[philsandy]

Have just bought an Judith Edge etched kit, a Stanier 3P 2-6-2T. Never built a kit before so it's all new territory.

Would like some advise on how to roll a tapered boiler. I don't have access to rollers so will need to do it by hand.

Found a diagram of a Stanier 3P 2-6-2T showing some dimensions. The boiler is  4' 2" (16.7mm) outer dia. at the front and 4' 9" (19mm) outer dia. at the rear. The etch is 0.015" N/S.

How would one go about rolling this to produce the correct taper, what diameter bar would I need, (slightly smaller than reqd. diameter?), is it best to anneal it beforehand? 

[Mark]

I usually clamp it over a bar in a vice first to form the edges as these are more difficult to form. Then it is just a case of using a bar which is stiff enough not to bend along its length. Keep rolling on a flat surface that has some give like a mouse mat or sleeping bag floor mat. You can form the taper by applying more force at the small diameter end as you roll it.

 

The pictures below should give some help with forming the edges.

 

I don’t anneal the metal personally. I have never found the need and the one time I did try it the metal became too soft.

 

Mark

[Michael Edge]

You will need to anneal this one since it's etched in nickel silver along with the rest of the loco. The bar in the suggestion above is a bit thin though, i would start with about 3/4" myself.

[Nig H]

I roll smokebox or boiler wrappers between two lengths of tube or rod, the one the wrapper goes round being of smaller diameter than that required for the wrapper. The wrapper needs to be fed between the two lengths of rod or tube, and these turned against each other, thus pulling the wrapper between them in a curve. You need to force the wrapper to follow the relevant tube by dragging everything away from that tube as you turn the tubes. Hard to explain but easy to do once you have a couple of goes. The rolled wrapper can then be eased out to the final diameter. I usually use tube of the appropriate diameter as an inner layer for the wrapper which should be a spring fit on the tube. The taper for the boiler wrapper is achieved by forcing some larger diameter tube or rod into the rear end of the rolled wrapper. I never anneal the wrappers but I model in 2mm finescale and the wrappers are usually only 0.125mm thick. If you want to try my method, start with some scrap etch to get the hang of it.

 

Here are some pics.

 

 

 

 

 

Hope this is of use. Please ask if you need further clarification.

 

Nigel Hunt

[Michael Edge]

I've never seen that idea before - looks like a sort of hand held rolling bars - seems to work well though.

[rab]

I suspect what may have been overlooked in the replies

so far is the OP reference to a  TAPERED boiler. 

I remembered learning about rolling tapers during

my apprenticeship but as that was over 50 years ago,

the details eluded me. So out of curiosity I googled

the subject and came across this link which may help:

 

http://www.westernthunder.co.uk/index.php?threads/looking-for-advice-rolling-taper-boiler.4898/

[philsandy]

22 minutes ago, rab said:

I suspect what may have been overlooked in the replies

so far is the OP reference to a  TAPERED boiler. 

I remembered learning about rolling tapers during

my apprenticeship but as that was over 50 years ago,

the details eluded me. So out of curiosity I googled

the subject and came across this link which may help:

 

http://www.westernthunder.co.uk/index.php?threads/looking-for-advice-rolling-taper-boiler.4898/

 

Thanks for that Brian, lots of good tips there, very useful.

[Michael Edge]

1 hour ago, rab said:

I suspect what may have been overlooked in the replies

so far is the OP reference to a  TAPERED boiler. 

 

That's the easy bit in this case, just roll it parallel to the smokebox diameter and then gently open up the other end - most of the taper is down between the tanks in this loco anyway.

[mark axlecounter]

I have done a few taper boilers for use on Mike’s kits, I do the same method as Mike said on Sunday ( just above my post ). 
I have done it on my princess kit and my stanier tank. 
im just building the Fowler 2-6-2 tank at present. 
Mike before you say anything yea I’ve nearly done that princess Loco ,just needs the motion doing lol 

 

 

[Jub45565]

Reawakening this, for the same kit, I've got an OK start without annealing - but the NS is a bit stiff to sort out properly.

 

I know annealing can be done on a gas hob, but how long do one heat it for? I presume the aim is to hold it in the tip of the flame?

 

This is the current state of play:

 

[Siberian Snooper]

Just long enough for it to go red.

 

 

[Michael Edge]

Heat it to red and then let it cool - before you pick it up!