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Boiler making torch

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Nick Welburn10/03/2022 09:25:40
128 forum posts

I’ve got a Cringle boiler kit on the bench, and I’m going to need to solder up a few bits on my Minnie when work gets underway.

I’m going to buy a torch for this, my borrow propane one was fine for a 10v crank. Now I guess I’m going to need a bit more heat.

I’m thinking about this… **LINK**

That should do the trick for a small boiler right?

Durhambuilder10/03/2022 09:49:29
72 forum posts
5 photos

Sievert every time, get a starter kit and add burners as required.

https://www.gasproducts.co.uk/blow-torches/sievert-gas-blow-torch-kits/sievert-general-purpose-gas-blow-torch-kit.html

Calor gas cylinders can be found quite cheaply at car boot sales and the like, don’t worry about size or condition once you have the cylinder you just swap it with the size you prefer at your local calor dealer.

Nick Welburn10/03/2022 09:52:27
128 forum posts

So I have one of these in the garage, any use? **LINK**

Bob Unitt 110/03/2022 09:55:28
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204 forum posts
33 photos
Posted by Durhambuilder on 10/03/2022 09:49:29
once you have the cylinder you just swap it with the size you prefer at your local calor dealer.

Check first - my local Calor dealer will only replace with the same size cylinder.

Edited By Bob Unitt 1 on 10/03/2022 09:56:24

noel shelley10/03/2022 10:02:19
1348 forum posts
21 photos

Seivert or bullfinch are both good names. If buying a starter kit make sure the regulator is big enough for the biggest torch you will use ! As a propane bottle is used, especially with a big jet, it will freeze and you will loose bottle pressure, the bottle may have plenty of gas in - it just can't boil off, bigger bottle less trouble. I would say use a 13 or 19Kg ! 3.9Kg is too small! Once below 1/3rd on cold days you may have to warm the bottle, pour warm water over it, DO NOT wrap it in a blanket ! If your near N Norfolk I can find you a bottle. Noel.

Edited By noel shelley on 10/03/2022 10:05:39

roy entwistle10/03/2022 10:02:20
1525 forum posts

Propane is hotter than Butane and I would think that Map cylinders are he dearest way of buying gas

Roy

Oldiron10/03/2022 10:23:25
976 forum posts
40 photos
Posted by Nick Welburn on 10/03/2022 09:52:27:

So I have one of these in the garage, any use? **LINK**

Always usefull. I do find that these GAZ cylinders/bottles although filled by Calor, work out to be very expensive. I always carry one as a backup in the caravan. I have all the accessories for them.Burner ring, Grill, Light & blowtorch.

regards

Andrew Johnston10/03/2022 10:28:31
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6602 forum posts
701 photos
Posted by Nick Welburn on 10/03/2022 09:52:27:

So I have one of these in the garage, any use?

No, it's for butane; you need propane. Temperature and heat are different things. Many of the small torches will reach the required temperature for silver soldering, but will not be able to supply enough heat. When I started silver soldering I had all sorts of problems, even with a Sievert torch. Turned out I didn't have a big enough burner, ie, not enough heat. By the time even small work got up to temperature the flux was exhausted. I second Sievert and propane.

Andrew

Oldiron10/03/2022 10:28:40
976 forum posts
40 photos
Posted by Bob Unitt 1 on 10/03/2022 09:55:28:
Posted by Durhambuilder on 10/03/2022 09:49:29
once you have the cylinder you just swap it with the size you prefer at your local calor dealer.

Check first - my local Calor dealer will only replace with the same size cylinder.

Edited By Bob Unitt 1 on 10/03/2022 09:56:24

Agreed. All Calor resellers have to abide by Calor's ruling that they can only accept like for like exchanges.

regards

Gerhard Novak10/03/2022 10:29:45
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109 forum posts
114 photos

The map gas set from toolstation is very good, the burners are easy to change, but I do not think they are good enough for a boiler. A very small one probably. I think the map set is more for silver soldering smaller parts together. Also: as you hold the bottle all the time your arm may get tired (Or minimum mine does....).

On a boiler the heat will "run away" because of the good thermal conductivity of copper. So you need plenty of power. The Sievert pro 86/88 burner has 7.7kW, this together with some thermal insulation (fire bricks) should do the job. Problem at the moment is to get a propane bottle. Some kind of shortage on the market.

Edited By Gerhard Novak on 10/03/2022 10:30:55

Dave Halford10/03/2022 10:38:18
2052 forum posts
23 photos
Posted by Durhambuilder on 10/03/2022 09:49:29:

Calor gas cylinders can be found quite cheaply at car boot sales and the like, don’t worry about size or condition once you have the cylinder you just swap it with the size you prefer at your local calor dealer.

Those were the days, now you need to check the Calor web site.

Some torches need a particular size of bottle to work properly.

Keith Hale10/03/2022 10:52:24
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333 forum posts
1 photos

Hi Nick,

Sievert every time until propane heating does not fit your needs. This is likely really when you might want a more defined flame.

The mapp or map torch is ideal for a plumber. It has a slightly higher flame temperature but may not deliver enough heat because it is not burning sufficient gas.

Heating is probably the biggest cause of brazing (silver soldering) problems usually resulting in poor joints.

Look beyond the headline price. You could be heading for higher costs later.

Why not discuss your requirements with someone who appreciates and understand what you want to achieve? Try CuP Alloys.

Why ask a storeman in a plumbers shed? Alternatively read my book. Either way, you will understand enough to buy any pre-loved equipment.

But buy sievert.

Keith

Durhambuilder10/03/2022 11:28:39
72 forum posts
5 photos
Posted by Bob Unitt 1 on 10/03/2022 09:55:28:
Posted by Durhambuilder on 10/03/2022 09:49:29
once you have the cylinder you just swap it with the size you prefer at your local calor dealer.

Check first - my local Calor dealer will only replace with the same size cylinder.

Edited By Bob Unitt 1 on 10/03/2022 09:56:24

You can swap within the same group eg a 4.5kg butane can be swapped for a 6kg propane.

https://www.calor.co.uk/gas-bottles/refills-and-returns/refills

Andrew Tinsley10/03/2022 11:44:53
1630 forum posts

No way is that torch going to work on anything unless it is very small indeed.

Use Propane and take heed of the size of regulator AND cylinder. For big jobs a small Calor cylinder will not provide enough gas per unit time.

As to torches and nozzles, most people say Sievert. I have a large range of Sievert stuff and an equally large range of Bullfinch torches and nozzles.

I much prefer the Bullfinch product, they are British made and they have an extremely good advice set up, if you need help.

When I was accumulating torches, the Bullfinch products were less expensive than Sievert. Both are good and should be your only choices.

Andrew.

JasonB10/03/2022 13:01:16
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Moderator
22751 forum posts
2653 photos
1 articles

You need to look at the output of the burner more than the temp the gas will burn at. For boiler work or any reasonably sized fabrications then about 7.5Kw would be a minimum and just so happens to be close to what the standard issue Sievert torches usually come with..

Even if a little torch may eventually get the job upto temp you will likely have exhausted the flux before it gets there.

You also want a high pressure regulator not the low pressure ones often used on Butane or low consumption propane fired items 2bar minimun, preferably adjustable upto 4bar

SillyOldDuffer10/03/2022 13:30:59
Moderator
8694 forum posts
1967 photos
Posted by Gerhard Novak on 10/03/2022 10:29:45:

...

On a boiler the heat will "run away" because of the good thermal conductivity of copper. So you need plenty of power. The Sievert pro 86/88 burner has 7.7kW, this together with some thermal insulation (fire bricks) should do the job...

Gerhard hits the nail on the head. The answer more about the ability of the torch to deliver heat, measured in kilowatts, than brand-names.

A lot of heat is needed to braze or solder large lumps of copper, especially if the lump isn't insulated. Heat isn't temperature. Gerhard mentions 7.7kW, which is certainly more powerful than the Vortex Map Torch sold by Toolstation. Toolstation don't specify their torches output, but the burner and cylinder are similar in size to my baby Sievert, which is only good for 900W. 900W is OK for brazing small parts carefully insulated by a firebrick igloo and is more than adequate soldering copper pipes, but I wouldn't attempt to braze a boiler with it. Not enough kilowatts.

Boiler work needs a big nozzle fuelled by a cylinder big enough to provide a high volume of gas. Cartridges are probably too small to deliver the necessary kilowatts. I'd talk to CupAlloys about the size of torch needed.

The original MAPP gas was a hot burning mixture of Methylacetylene, Propadiene and Propane, often used instead of Acetylene (also hot burning). Good stuff, but it's not made any more, I believe because Methylacetylene was a by-product from a chemical process now obsolete, and the amount of MAPP sold doesn't justify setting up a dedicated plant. Current 'MAP' gases are mixes of Butane, Propane and perhaps Propylene - they burn at a higher temperature than Butane and Propane, but are cooler than true MAPP. I think MAP is a bit of red-herring too - its about kilowatts rather than temperature.

Dave

Thor 🇳🇴10/03/2022 13:34:09
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1630 forum posts
46 photos

I too use Sievert equipment for my silver soldering (brazing), mine is a couple of decades old and still works well. As Jason says, the heat output (kW) of the burner is more important than the temperature.

Thor

Bazyle15/03/2022 20:41:19
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6324 forum posts
222 photos

Just on Friday at an EDMES meeting one member told me he couldn't get a calor refill because they had no small cylinders - bit of a run on them due to people perhaps cooking on gas to save electricity. He had to get a 19kg one to exchange.

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