By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

Boiler Formers

Material other than steel for copper boiler formers.

All Topics | Latest Posts

Search for:  in Thread Title in  
Steve Bright 226/10/2021 22:44:49
17 forum posts
14 photos

Hi all,

a bit of advice please, I hope this is the right section for this question.

I am planning on making the Reeves 2-6-2 Prairee in 5" guage. It is a super detailed plan and copies the shape of the belpaire boiler quite well.

The tubeplate is a typical round with a flange and in such cases I have turned a steel former and followed the normal procedure of clamping the annealed plate between two plates, beating reannealing etc.

The throatplate follows typical design with a flanged hole for the taper and an opposite outside flange for the firebox wrapper. The firebox backplate and the backplate are to me unusual in that the firebox back has an outward facing flange for the firehole that mates with an outward flange on the boiller backplate, so no firehole tube.

So there are three plates that have outside flanges in one direction and flanges in the opposite direction. All these are typical belpaire shape.

I have in my mind the method of forming the plates, form the holes first and use that as a register in the clamping plate on a forming plate with a matching male section to hold the plate for forming. So any plate is going to take quite a lot of hammering. I don;t have acces to a steel bandsaw and don't fancy cutting steel formers.

What alternatives are there to steel please? I have a wood bandsaw and router, available. There is a hardwood timber yard not too far away and I have offcuts of MDF but I am doubtful if MDF will be strong/firm enought.


bernard towers26/10/2021 23:14:32
619 forum posts
109 photos

There is a super heavyweight density fibreboard available, the offcuts I have had in the past are incredibly hard.

Peter Simpson 327/10/2021 07:26:01
40 forum posts

Hi Steve, I'm making a BR Standard 2 boiler at the moment. I got M-Machine to lazer cut all of my flanging plated out of 12mm steel. Check around your location for lazer cutting companies.

JasonB27/10/2021 07:31:50
22751 forum posts
2653 photos
1 articles

For single use a bit of hardwood such as beech should be upto the job, worked for this part. If you can find an offcut of solid wood worktop that will be ideal or even a cheap cutting board

Buffer27/10/2021 08:15:20
338 forum posts
153 photos

Plywood is fine it will stand up for single use with no problems at all.




And you can use plywood any old bits of softwood and p38 filler to to make formers for the firebox wrapers like this.  If you have a bandsaw you really have no problems.



Edited By Buffer on 27/10/2021 08:26:11

Edited By Buffer on 27/10/2021 08:33:11

Bo'sun27/10/2021 08:22:33
609 forum posts
2 photos

Another vote for Beech formers.

Buffer27/10/2021 09:13:13
338 forum posts
153 photos

I've just read your post again and that fire hole sounds really hard to make to me. Can't you just fit a tube within a tube? I would think trying to flange those holes to line up would be a bit of a nightmare.

Edited By Buffer on 27/10/2021 09:13:37

Nigel McBurney 127/10/2021 09:49:59
1000 forum posts
3 photos

I used .5 and .75 aluminium plate for my Allchin TE boiler and tender formers, they were also loaned out to another Allchin builder, The aluminium plate came as off cuts which were free,

Samsaranda27/10/2021 10:03:07
1430 forum posts
5 photos

Digressing slightly, I am about to commence, with some trepidation, to construct the boiler for the Allchin 1 1/2” scale Royal Chester that I am making and I am following this article with interest. I would prefer to purchase flanging plates ready made rather than have to reinvent the wheel so to speak, but I don’t think that they are available, failing that perhaps someone has some that they would be prepared to lend or even sell. I see Peter had his made from 12 mm steel, is this the optimum thickness to use and I am thinking perhaps using M-Machine to fabricate as he did, there aren’t as many engineering facilities here in the South East as there are in the Midlands and the North so choice of suppliers very limited. Dave W

Samsaranda27/10/2021 10:04:59
1430 forum posts
5 photos

Just seen Nigel’s post which popped up as I posted the above, so Aluminium plate is also a contender. Dave W

Steve Bright 227/10/2021 10:16:46
17 forum posts
14 photos

I get my steel plate from a local engineering firm that has laser cutting, so that is a possibility. But from the drawings you can see the shape of the plates I have to form.

I like the idea of beech and the local timberyard should have some and as in my previous like I was a joiner I can work it easily and get a good finish. It also means I can easily add extra parts to register the firehole either to fprm it or act as a register to form the outer flanges.

Buffer, I suppose it would be possible, but I like a challenge and as the drawings show a hole centre that gives me a good datum to set out from.

Hole centres.


Side views




Dave Smith 1427/10/2021 11:04:12
213 forum posts
43 photos

I used plywood for the flanging on my Aspinall and 3D printed formers for outer and inner wrappers, which work a treat. I have also used a 3D printed former successfully to reshape one part when I got plywood shape wrong.

Hope the following photos may be of interest to some people.

First couple of photos show the 3D formers.



This photo shows the laser cut and 3D printed drill jig I made to get all the bits in the right place.



Where I am


Trial fir in chassis.


Samsaranda27/10/2021 11:25:37
1430 forum posts
5 photos

Nigel, I have sent you a PM. Dave W

Phil H127/10/2021 11:46:20
459 forum posts
60 photos


Would it be possible to take a couple of pictures of your outer wrapper to throatplate joint please. That looks like an interesting joint for round top boilers.

Phil H

Dave Smith 1427/10/2021 22:30:49
213 forum posts
43 photos


The joint is basically as per Don Youngs drawing. The only change I made was to the outer wrapper to include the little 'ears' that line up with boiler tube flange. The throat plate is double flanged, hopefully this picture will explain the joint, note the bottom of the throat plate and the wrapper have not yet been trimmed to length.. If you want more detail let me know.


Nick Clarke 328/10/2021 09:22:58
1427 forum posts
63 photos
Posted by Bo'sun on 27/10/2021 08:22:33:

Another vote for Beech formers.

Take care sawing woods like beech (aka old school desks) as the dust is not good for you

Baz28/10/2021 09:36:31
724 forum posts
2 photos

Love the 3D printed formers. I have used ally plate for flanging formers with great success, cnc milled on a Taig Micromill out of 10mm ally plate.

Phil H129/10/2021 11:50:01
459 forum posts
60 photos

Thanks Dave, excellent picture.

Phil H

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
Eccentric July 5 2018
Rapid RC
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest