hi. the torch should give enough heat but it will be difficult to be precise with it on a little 3.5". In my experience they are no where near hot enough for 5". Even with oxy at 5" you need a lot of heat. Last 3,5 I did was a juliet, started cutting material saturday morning and completed it sunday afternoon, and that was TIG'd, what a piece of cake that was! If it helps im in nw uk, have every weld type reasonably possible, you are welcome to use my workshop and equipment at the cost of the gas/wire etc.

Have been told that TiG welded boilers will only be tested if they were welded by a qualified (certified) welder ?? or is this only for Stainless steel and does not include Copper boilers ???!!

Hi Terry,

Declared interest – I have recently retired from the company but a link still exists. I only provide technical information. See your private messages.

Keith

Steve (I'm not Keith, but I'll butt in here)

– Kozo Hiraoka made his 3-1/2" gauge boilers with just a propane torch. Find one of his books on building his locomotives and have a read. They are well worth it, IMHO.

– My first 2 boilers made with just a propane torch. (Sievert, one large burner – I can look up the # if you wish) Two Tich boilers – first one was "I've never worked with copper" and decided after it was complete that I could do better, so kit from Reeves ordered and 11 HOURS of work produced a Tich boiler still working fine.

– I do have a Kozo Shay boiler mainly completed with my 1 propane burner.

– recently finished a Martin Evans "Ivatt" boiler. Mainly propane.

Ok – problems/issues.

1) The propane burners I have inject air in by the burner head, so they can go out if the air intake is restricted, like working in a firebox, for instance. A friend has a propane burner with air intake close to the handle, so that is a better one than mine.

2) I put firebrick on my barbecue and do the work outside. Propane flames can get blown around by the wind, and it does not take much wind to do the blowing. It's a wide, "soft" heat.

3) My firebricks are the hard, heat absorbing bricks; I should use the softer heat reflecting bricks, but have not bothered so far.

Solutions.

My Air/Acetylene torch with biggest burner works wonders. More "firm" flame than Propane, not as hot and specific as OxyAcetylene.

Doing fireboxes, leave the backheads (inner and outer) off and put them on as the last 2 operations – this leaves the firebox open and combustion works well.

—

All 3 successful boilers done without any help. I would like to make two Q1 boilers fairly soon, and do not expect to require any outside help. I do have a larger 7-1/4 boiler to complete (model like Aegnoria in the York museum) and I think I'll get some help there. We'll see.

The worst part of building a boiler yourself is the contemplation!

Another JohnS.

That's all pertty usefull information John.

I have just had a quote back from a model supplier.

22 months lead time.

20% up front.

£1750 cost now with the possibility of the price going up at the time of construction.

EEEK i think i need to change skills if they have an order book with 22 months worth of work in it!

Bri

Edited By Boiler Bri on 19/09/2013 19:08:36

It’s no good having a burner which is ‘ adequate ‘ for the job . Really you need one which will heat the job rapidly – no more than a few minutes from all cold to job done .

The work is deteriorating all the time it is under heat and any joint that has to be heated for ages before solder runs properly is likely to be less successful than one done rapidly .

Often better to use two modest size burners than one great big one . An assistant applies general heat with one burner while you use the other burner to put direct heat into the joint area .

Forced air propane burners are usually better than self blowing types for boiler making .

Some great experts like LBSC always advocated the use of a ‘ scratcher ‘ when silver soldering . Jury’s out on that one – scratcher might save the day if silver soldering is not going too well but personally I take the view that if solder is not running clean then something is wrong- so cool down , pickle and investigate .

MikeW

Thanks for the comments John. I felt that propane should be fine and no need for oxy-Aceteleyne. I have dreams of a 5" sweet pear or 71/2" narrow gauge so have started collecting various sievert burners. Glad I am on the right track.

Steve

One memory that might be useful – A Speedy boiler was once satisfactorily completed using two Sievert burners about 1.5 inch diameter going flat out . Simple coke bed and a few bricks to conserve heat .

Job was done just at twilight on a calm night – the old advice proved sound on that occasion .

MieW