Silver Soldering Brass

[Bill PhinnParticipant @billphinn90025]

Chris, I've got the Smith Little Torch, which I use with an oxycon.

Even with the optional rosebud tip attached, it's not big enough for silver-soldering what I would class as medium to large projects. That's why I have a bigger oxy-propane rig-out and also the propane-only Sievert with a range of burners, of which the 7.7KW one is currently my third biggest.

Basically you need the right torch with the right burner turned up to the right setting for each job; depending on the range of work you do, that might mean having a range of torches, burner sizes and even fuelling systems.

You don't say how big the two pieces of brass are that you were trying to join, but it's quite likely your two mini torches weren't getting enough heat into enough of the work fast enough. I'm assuming the joint characteristics, including fluxing and cleanliness, were good, as was your way of directing what heat you had at your disposal on to the work.

I I were you I'd snap Noel's generous hand off, and be hesitant at this stage about buying the all-in-one kit you linked to; you may well find yourself starved of oxygen breathtakingly quickly.

[Old SchoolParticipant @oldschool]

My father was a clock maker made a living making clocks from scratch everything was done in the workshop at home . He used a Sievert type torch with a couple of different sized burners. I have it now and still use it. Not into clocks but still have most of his hand tools.

[Paul KempParticipant @paulkemp46892]

A propane torch with a range of burner sizes is all you need. I have a caravan size propane cylinder and a Micky Mouse Clarke propane torch kit with an adjustable reg, no idea of the Kw sizes of the burners but they range in diameter from about 3/8" to probably 3" it also has a gas soldering iron for soft solder comprising a copper bit with integral torch which I used quite succesfully to soft solder 1/2 round brass beading to my 4" traction engine steel tender. Last weekend I silver soldered a steel bush for the oiler 5/8" diameter onto a steel fabrication comprising a 2" length of 1 1/4 round bar previously welded to legs of 2" wide 1/4" thick steel flat bar so a fair old lump of steel. All done in what is essentially a CuP brazing hearth with HP5 flux using the 1 1/2" burner. No problem at all. I don't profess to apply any science to the choice of burner for any given job outside "that looks big enough"! For small jobs I use a self contained plumbers style torch with a propane aerosol size cylinder and the small nozzle of the pair it came with. As others have said if you can contain / reflect back the heat loss with some decent insulating bricks or mineral blanket, Charlies your aunt! I very much doubt you will find any clock bits barring one from the cathedral that sort of rig won't manage. I doubt the whole set up over the years has cost me more than £70 and I even used it in conjunction with a wood burning basket to harden and temper the front spring for my 6" TE. You can spend a fortune on kit but if you haven't developed the technique the job will be no better!

Paul.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Chris TickTock on 15/01/2020 20:23:57:

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I am still weighing up the pros and cons. My usage will be in clock repairs. For example if for any reason I needed to repair (solder) a tooth into a large brass wheel I would I feel be constrained to using soft solder […]

.

… That would be the safer option anyway; particularly on 18th Century Brass

[ there was another recent thread here, on that very topic ]

MichaelG.

[roy entwistleParticipant @royentwistle24699]

I've been repairing clocks for nearly 70 years and I've not found a need to silver solder. A proper soft soldered joint has always worked including main spring barrels

Roy

[Chris TickTockParticipant @christicktock]

Posted by roy entwistle on 15/01/2020 21:43:18:

I've been repairing clocks for nearly 70 years and I've not found a need to silver solder. A proper soft soldered joint has always worked including main spring barrels

Roy

Hi Roy,

Yes many clock repairers would agree with you and all I can add is that silver solder may be viewd as an alternative repair method in certain cases.

Chris

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Keith HaleParticipant @keithhale68713]

Hi Chris

Save yourself a lot of time and money, frustration and poor joints by getting to understand the process.

Silver soldering is a very simple process as long as you understand what you are doing and why. Then do it.

BUT IF YOU DEVIATE FROM THE BASICS OR TAKE SHORTCUTS (and there are lots of them on the forums!) YOU WILL RUN INTO DIFFICULTIES.

CuP Alloys have a good book (I wrote it!) that will definitely point you in the right direction.

Taking a little bit of time now will reap great rewards in the future.

Regards

Keith

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Keith HaleParticipant @keithhale68713]

Hi Chris,

Do not use borax flux with silver solder. It does not start to work until you have overheated the joint and alloy.

If using easiflo you will certainly be boiling cadmium from the alloy. These fumes can,a eventually wil, kill you. It was this hoo-haw that led to the banning of the sale of easiflo and other cadmium bearing alloys.

Ring CuP Alloys on 01623 707955 for more information. To get specific information on your problem ask them for the contact details to enable you to set up a video link via Skype or WhatsApp.

Alternatively go speak to them at Ally pally over the weekend.

But put that borax in the bin unless your filler metal is brass.

Keith

[Chris TickTockParticipant @christicktock]

Posted by CuP Alloys 1 on 16/01/2020 16:26:56:

Hi Chris,

Do not use borax flux with silver solder. It does not start to work until you have overheated the joint and alloy.

If using easiflo you will certainly be boiling cadmium from the alloy. These fumes can,a eventually wil, kill you. It was this hoo-haw that led to the banning of the sale of easiflo and other cadmium bearing alloys.

Ring CuP Alloys on 01623 707955 for more information. To get specific information on your problem ask them for the contact details to enable you to set up a video link via Skype or WhatsApp.

Alternatively go speak to them at Ally pally over the weekend.

But put that borax in the bin unless your filler metal is brass.

Keith

Thanks Keith I will do that. I have decided for better or worse to go with the Smith little Torch. That is now decided but before ordering it I have to look at the acetylene v propanr routes. my usage will be mostly silver soldering so anyone who can add some value here is more than welcome.

Chris

[Michael GilliganParticipant @michaelgilligan61133]

Posted by CuP Alloys 1 on 16/01/2020 16:26:56:

Hi Chris,

Do not use borax flux with silver solder. It does not start to work until you have overheated the joint and alloy.

[…]

But put that borax in the bin unless your filler metal is brass.

Keith

.

Keith,

I hope you will forgive me the impudence of adding a footnote [*] to your excellent advice.

… especially as I am straying from the specifics of this thread.

[*] Although unsuitable for the materials under discussion; Borax is widely and successfully used when Silver-Soldering Silver.

MichaelG.

[Chris TickTockParticipant @christicktock]

Posted by Michael Gilligan on 16/01/2020 16:56:19:

Posted by CuP Alloys 1 on 16/01/2020 16:26:56:

Hi Chris,

Do not use borax flux with silver solder. It does not start to work until you have overheated the joint and alloy.

[…]

But put that borax in the bin unless your filler metal is brass.

Keith

.

Keith,

I hope you will forgive me the impudence of adding a footnote [*] to your excellent advice.

… especially as I am straying from the specifics of this thread.

[*] Although unsuitable for the materials under discussion; Borax is widely and successfully used when Silver-Soldering Silver.

MichaelG.

Thanks Michael, that is useful to know.

Chris

[Bill PhinnParticipant @billphinn90025]

Posted by Chris TickTock on 16/01/2020 16:46:06:

I have decided for better or worse to go with the Smith little Torch. That is now decided but before ordering it I have to look at the acetylene v propanr routes. my usage will be mostly silver soldering so anyone who can add some value here is more than welcome.

Chris

 

I'd say acetylene is unnecessary for your purposes.

Be careful where you buy your Little Torch. There is a wide variation on price* and many non-genuine and downright dangerous impostors are being offered for sale in certain marketplaces.

*even on the genuine item.

Edited By Bill Phinn on 16/01/2020 17:24:33

[Chris TickTockParticipant @christicktock]

Posted by Bill Phinn on 16/01/2020 17:23:43:

Posted by Chris TickTock on 16/01/2020 16:46:06:

I have decided for better or worse to go with the Smith little Torch. That is now decided but before ordering it I have to look at the acetylene v propanr routes. my usage will be mostly silver soldering so anyone who can add some value here is more than welcome.

Chris

I'd say acetylene is unnecessary for your purposes.

Be careful where you buy your Little Torch. There is a wide variation on price* and many non-genuine and downright dangerous impostors are being offered for sale in certain marketplaces.

*even on the genuine item.

Edited By Bill Phinn on 16/01/2020 17:24:33

Thanks for this, I agree many dodgy copies in genuine boxes apparantely…will go with CooksonGold.

Chris

[Chris TickTockParticipant @christicktock]

Just a post to state my thanks for the many helpful posts to date.

I decided to go with the Smith Little Torch due to its stable gas delivery and quality. I have learned much todate about silver soldering.

On my clock forum it is suggested I attend a demonstration of the Smith Little torch using both acetylene and propane so I can evaluate which is better. I am minded this is not likely to be easy to find especially as my interests are only with clocks and therefore mostly brass. Unless there is someone with a Smith little torch who can either demonstrate or advise I feel it's one of those occasions that I will just have to get on with life. Thanks to Noel for offering to demonstrate his range of silver soldering burners but I have decided it has to be the Smiths for me so spending several hours on a different torch seems upon reflection a bit pointless. Nonethe less a big thank you for noel's offer.

Cup alloys have been very helpful and rang me with advise.

Next stage is to source all;l equipment and practice. As a sid enote I learned my initial failure at silver soldering was lacking any real knowledge and that the job would be more suited to brazing or even riveting.

I believe all Easy Flo solder is now cadmium free so at least there is one less issue there.

On a final point are there any draw backs to getting a used Oxy concentrator in place of a cylinder and I believe I am right an oxy concentrator does not need the regulators / arrestors as the cylinder does, but still investigating this.

Chris

 

Edited By Chris TickTock on 18/01/2020 14:58:06

[JasonBModerator @jasonb]

I doubt that repair could have been rivited and look anything like original, you would have needed to add an additional "L" shaped piece and rivit the two broken bits to that.

Silver soldering is actually brazing but this is again were your visits to American sites can cause confusion as they oftehn refer to silver soldering as brazing where as in the UK it is generally regarded as using a higher melting point filler rod that in most cases won't melt with Propane alone.

Old Easy-flo is still called that anything you buy now will more than likely be Silverflo if made by JM. If you are able to buy Easy-flo then the seller is breaking the law and you are aiding and abetting. Flux still uses the Easy-flo name again if a JM product.

Enjoy your torch and just remember you now have a torch capable of completely melting brass parts so take it easy.

[Chris TickTockParticipant @christicktock]

Posted by JasonB on 18/01/2020 15:39:00:

I doubt that repair could have been rivited and look anything like original, you would have needed to add an additional "L" shaped piece and rivit the two broken bits to that.

Silver soldering is actually brazing but this is again were your visits to American sites can cause confusion as they oftehn refer to silver soldering as brazing where as in the UK it is generally regarded as using a higher melting point filler rod that in most cases won't melt with Propane alone.

Old Easy-flo is still called that anything you buy now will more than likely be Silverflo if made by JM. If you are able to buy Easy-flo then the seller is breaking the law and you are aiding and abetting. Flux still uses the Easy-flo name again if a JM product.

Enjoy your torch and just remember you now have a torch capable of completely melting brass parts so take it easy.

 

Hi Jason,

Yes I have an angled piece of brass and will look at riveting this or not in time. The site I got the information about the differences between Silver soldering and brazing actually was not the clock forum but thewelderswarehouse, it basically stated the difference between welding where the metal itself is melted and joined and soldering and brazing where only the filler metal is melted. You know all this so I see no point teaching you to suck eggs. Your right there is some jargon confusion but I get that.

 

At the moment I am nearly there but have to understand a bit more over gas pressures. You can get suitable oxygen regulators for a different range i.e 0 – 3.5 and 0 – 10 bar but what do I need?/ Also apparently if you connect a propane cylinder all you need is a camping type regulator don't understand how pressure is maintained, is that a property of the cylinder being compressed if so surely it diminishes at some point?

update I now think I should fit regulators with dials having the 0 to 3.5 Bar range  as the Smith little torch uses under 5 psi. (watched a Cookson gold video, very helpful)

chris

Edited By Chris TickTock on 18/01/2020 16:04:24

Edited By Chris TickTock on 18/01/2020 16:39:53

[Paul KempParticipant @paulkemp46892]

Not sure about 'dials' with a 3.5 bar range if you are looking for less than 5 psi. 3.5 bar is around 50 psi so using a gauge to measure 1/10th of its range is not going to be terribly accurate? I know nothing of the Smiths torch or the bottles it will be combined with but usually oxygen and acetylene regulators have a gauge on either side, inlet will be high reading showing cylinder pressure and giving an idea of contents, outlet will be line pressure to the torch. Also be sure to understand you generally screw regulator control in to increase pressure and out to reduce.

Paul.

[Chris TickTockParticipant @christicktock]

Posted by Paul Kemp on 18/01/2020 18:03:57:

Not sure about 'dials' with a 3.5 bar range if you are looking for less than 5 psi. 3.5 bar is around 50 psi so using a gauge to measure 1/10th of its range is not going to be terribly accurate? I know nothing of the Smiths torch or the bottles it will be combined with but usually oxygen and acetylene regulators have a gauge on either side, inlet will be high reading showing cylinder pressure and giving an idea of contents, outlet will be line pressure to the torch. Also be sure to understand you generally screw regulator control in to increase pressure and out to reduce.

Paul.

Good to see you are awake and spotted my typo. 5 psi is .35 not 3.5 Paul …well spotted

Chris

[nigel jones 5Participant @nigeljones5]

Ive never met anyone using a generator for brazing, not saying there aent any, but I have seen them used on youtube. With an average flow rate of about 2 litres per minute (five max) at ambient pressureyou would not be able to burn with a decent flame for anything but the smallest of jobs. Fine for very small work but dont even think about using it on a boiler anything bigger than a mamod. Given that you can easily get the same and a lot more heat out of a b&q £20 prop torch the cost would be very prohibitive…But, for super fine/fiddly jobs you would have a lot more heat control and accuracy so it does have a place in some workshops.

[Chris TickTockParticipant @christicktock]

Posted by fizzy on 18/01/2020 20:56:06:

Ive never met anyone using a generator for brazing, not saying there aent any, but I have seen them used on youtube. With an average flow rate of about 2 litres per minute (five max) at ambient pressureyou would not be able to burn with a decent flame for anything but the smallest of jobs. Fine for very small work but dont even think about using it on a boiler anything bigger than a mamod. Given that you can easily get the same and a lot more heat out of a b&q £20 prop torch the cost would be very prohibitive…But, for super fine/fiddly jobs you would have a lot more heat control and accuracy so it does have a place in some workshops.

 

Hi Fizzy,

When I first come across people advocating a oxy con I thought what a good idea. oxygen in a cylinder is around 99%. Howevever oxygen in a oxy con is nearer 90%. This effects the flame stability and temperature. Therefore i agree with you and have reverted to theidea of using a cylinder. Also as an occasional user the cost of maintenance of a oxy con as it inevitabely needs maintenance / replacement is not more attractive than the reliability of a cylinder.

I note Fizzy you are an advocate for oxygen / propane so any tips greatly appreciated.

Chris

Edited By Chris TickTock on 18/01/2020 22:17:51

[not done it yetParticipant @notdoneityet]

I’ve used our oxycon for brazing. Only for small jobs. There are 10 lpm versions available – mine is only a 5 lpm version). They are great for lampwork (just soda glass, not pyrex type) but limited for jobs needing more heat with a high enough temperature.

One also needs to take into account that the output is about 98% oxygen (with noble gases making up most of the rest) but only around 88%, at best, at full flow. That extra dilution does affect flame temperature.

 

Edited to add that we’ve had our oxycon for several years.  Not used that much but we just switch it on.  These things are used by people who require oxygen on a day to day basis and are very reliable.  Mine was a reconditioned item, no longer to be used for medical purposes

Edited By not done it yet on 18/01/2020 22:34:07

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Chris TickTock on 18/01/2020 16:01:20:

.

 

[…] don't understand how pressure is maintained, is that a property of the cylinder being compressed if so surely it diminishes at some point?

.

You might like this video,Chris

Excellent graphics, and scrolling subtitles : **LINK**

MichaelG.

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Edit: Just found the Owners Manual for the little torch:

 https://www.millerwelds.com/files/owners-manuals/o263357b_mil.pdf

… and a detailed brochure:

https://www.millerwelds.com/-/media/miller-electric/imported-mam-assets/spec-sheets/2/d/e/ge200-the-little-torch-kit.pdf

Edited By Michael Gilligan on 18/01/2020 23:19:59

[Chris TickTockParticipant @christicktock]

Posted by Michael Gilligan on 18/01/2020 23:00:22:

Posted by Chris TickTock on 18/01/2020 16:01:20:

.

[…] don't understand how pressure is maintained, is that a property of the cylinder being compressed if so surely it diminishes at some point?

.

You might like this video,Chris

Excellent graphics, and scrolling subtitles : **LINK**

MichaelG.

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Edit: Just found the Owners Manual for the little torch:

**LINK**

… and a detailed brochure:

**LINK**

Edited By Michael Gilligan on 18/01/2020 23:19:59

Thanks Michael useful links

I note in the smiths little Torch manual it states 'when using natural gas a minimum of 1 pound pressure is required'. What is meant by 'natural gas'?

Chris

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