making a 3.5 inch boiler

Hi chaps, with the price of cylinder rentals being a major factor in my no longer having excess to oxy gas.I wonder if someone could let me know if the following would be ok for the making of a 3.5 copper boiler.I am thinking of using a propane touch with a forge.or should I go for a compressed air and propane touch and forge.what are your views.also if I do ok with the 3.5 inch boiler, I may try to make a 5 inch one.gain what way is best.michael

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.

Thanks for the offer.when you say you tiq welded the boiler.what was the process and the equipment you used.I am in somerset, would love to take you up on your offer, but as a new boy feel that I would drive you mad.Michael

Fizzy, i have pm'd you.

Bri

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.

Hi Terry

Have you considered oxy-mapp gas?

The kit has bottles that you own and exchange when empty.

No rental charges, no admin charges

regards

keith

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 ???!!

Keith. Where do we go for your suggestion

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

keith

What sort of size copper silver soldered Boiler do you believe is feasable with just two Siveret propane torches with a good selection of burners ijncluding cyclones available. I pressume some sort of size is possible as in the old days they mainley had parrafin blowlamps.

Steve

Hi, I think that mapp gas would soon run out, I have looked at my inbox and can, t see any messages.michael

Hi Michael,

The mapp gas is a cylinder - not a canister.

Check your inbox again.

regards

keith

PS There is a clue in the pen name!

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.

Thanks John,

You post is a really useful overiview.

Neil

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

Hello Steve,

Good stuff from John.

The burners with the holes nearer the handle are called cyclone burners.

The key is keeping the heat in. Compliment the effect of the lightweight bricks with a ceramic blanket.

Use a long life flux like HT5.

regards

keith

Michael;

Not disagreeing, but adding/observing;

1) I think in hindsight that the reason that I get away without a "helper" is that, yes, fairly big burners, and also, the boilers are small.

Small boilers == heat flows through the boiler much faster than with (say) a larger boiler. So, it all comes up to temperature faster, and (because of the larger burners) heat "stays" and does not radiate away.

Not sure if it is worded properly, but "scaling" here helps in more ways than apparent at first.

2) "LBSC" scratcher - never used one until recently, and it was used because I pre-locate silver solder, but sometimes it moves due to flux bubbling. my "scratcher" is used to re-position silver solder before it melts, but after the flux melts - make sense?

(my "Turbotorch Air/Acet. burner of choice is the A32 - which is, IIRC, 32 cu.ft Acetelyene per hour burn rate)

(whilst I have smaller burners for both Propane and Air/Acet; , I never seem to use them; small stuff (boiler fittings, etc) is done with a small plumbers torch on one side of my workshop; anything larger is done outside with my large burners)

Another JohnS.

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

no pm??