High Temp Solder

[Phil CashmanParticipant @philcashman42796]

I need to repair a steam line fitting connected to my boiler and it requires high temp solder. I am unable to use Silver Solder due to location and cladding which is in place between the solder job and the boiler. Due to shipping regulations to Canada, I am unable to get specific flux for the high temp solder. Can I just use normal plumbers solder and still expect a good joint with a solid bond?

[Phil CashmanParticipant @philcashman42796]

[JohnFParticipant @johnf59703]

Phil I think more info is required to answer your question, what's the boiler for, what pressure is involved, what size pipe ?

Do you have any silver solder? What composition is the plumbers solder in Canada? In the U.K. It's around 50/50 or 40/60 tin/lead, tinmans is 60/40 tin/lead, tin to plumbers lead free solder is stronger and more fluid when molten.

Remember with any soldering cleanliness is essential!

John

[MWParticipant @mw27036]

Could you use a brass based hard solder if you're looking at high temp?

Michael W

[pgk pgkParticipant @pgkpgk17461]

Someone else more knowledgeable might comment but i vaguely recall reading that pig fat was an old substitute flux for lead based solders.. might just be worth trying the high temp solder ona test-piece using that if others agree…

[Phil CashmanParticipant @philcashman42796]

I apologize for the original post having an error. It should have said "Can I just use normal plumbers solder flux and still expect a good joint with a solid bond?

The boiler is for my 5 inch Gauge Locomotive working at 80 psi. We tried to use normal plumbers solder on the last repair but after a while a small leak developed. The pipe is 3/16 thin walled copper and goes into a fitting which, due to it's location, precludes the use of silver solder. For that reason I have obtained some Comsol high temp solder with a melting point of 296 degree C from Blackgates. A problem with that is that I am totally unfamiliar with that product. Our solder is "silver bearing lead free solder" with a 221 degree C melting point, but none of the packaging states the actual properties. The Comsol should be better able to stand up to the temp and pressure but the big question is will our "Lead Free Solder Paste Flux" work with it? Leaded solder is impossible to find here so the only Flux is based on lead free.

[pgk pgkParticipant @pgkpgk17461]

According to this comsol data sheet: **LINK**

The comsol described with temp 296 actually has very high lead content 93.5%. The data sheet describes the flux they recommend.. so compare it's properties (corrosive type flux) to what you have available.. and try on a test piece?? Or the pig fat? Or contact Johnson Matthey technical

[Michael GilliganParticipant @michaelgilligan61133]

Posted by pgk pgk on 04/01/2017 07:17:26:

According to this comsol data sheet: **LINK**

.

Could you check that link please. pgk pgk … it appears to be a local file:

http://file///C:/Users/cwmfarm/AppData/Local/Temp/Comsol.pdf

Thanks

MichaelG.

[Phil CashmanParticipant @philcashman42796]

Thank you for your attempts with the link but it must be a local file which I am unable to get to. I have made two attempt to contact Johnson Matthey beginning in early Dec but so far with no response.

I am concerned that doing a test piece will lead to a wrong conclusion and end in complete failure of the boiler fitting while running.

I am hopeful that I will discover a definitive answer somewhere short of flying to England and bringing the Flux back in my luggage. In the interim I will attempt to locate that data sheet on line.

[Clive HartlandParticipant @clivehartland94829]

You want a Zinc flux or Muriatic acid flux. Prepare the piece by abrasive cleaning and 'Vee' out the crack in the pipe. You want as much surface contact as possible with the applied solder. Hence the 'Vee' preparation.

Maybe a better repair is to cut the pipe, find a piece of tube that will fit over it and cover the damaged bit and solder it on. Doing the same at the other end.

Clive

[pgk pgkParticipant @pgkpgk17461]

Posted by Michael Gilligan on 04/01/2017 08:47:19:

Posted by pgk pgk on 04/01/2017 07:17:26:

According to this comsol data sheet: **LINK**

.

Could you check that link please. pgk pgk … it appears to be a local file:

http://file///C:/Users/cwmfarm/AppData/Local/Temp/Comsol.pdf

Thanks

MichaelG.

Sorry about that.. below is the correct link

**LINK**

[mark smith 20Participant @marksmith20]

Why dont you contact AIM in Montreal , a big manufacturer of specialist solder/fluxes etc..who sell worldwide, im sure they would advise on something appropriate with a recommended retail supplier in Canada (if they dont supply to the public). I suspect many types of flux would work ok.

http://www.aimsolder.com/aimsolderproducts?gclid=CN-F2KqTqdECFYk_Gwodo0oNWQ

 

Heres a link to some of the solders they sell.

http://www.aimsolder.com/sites/default/files/alloy_chart_sept14.pdf

 

Also here for high temp solders which includes the same composition as yours and recommends 3 types of flux.

http://www.aimsolder.com/sites/default/files/aim_hmp_solder_sheet.pdf

Edited By mark smith 20 on 04/01/2017 18:51:02

Edited By mark smith 20 on 04/01/2017 18:52:34

Edited By mark smith 20 on 04/01/2017 18:53:25

Edited By mark smith 20 on 04/01/2017 19:08:03

Edited By mark smith 20 on 04/01/2017 19:15:03

[Michael GilliganParticipant @michaelgilligan61133]

Posted by pgk pgk on 04/01/2017 17:37:22:

Sorry about that.. below is the correct link

**LINK**

.

Much appreciated … a useful reference.

MichaelG.

[JohnFParticipant @johnf59703]

Hi all, Clive I don't see where Phil says there is a crack ? Am i missing something?

Phil IMHO the plumbers flux should work well, I'm assuming it is same or similar to the product available in the UK for lead free plumbers solder, it is a white paste, this is an acidic self cleaning flux — I have researched this for a particular job I do and see no reason why it will not suit your application. Its not suitable for mine !

However assuming that what you describe is a thin wall pipe going into a female socket ** –same as a regular soldered plumbing fitting, I would do a test using a regular plumbing fitting and pipe say 10mm then cut the assembly longitudinally to see the result. Providing the solder has penetrated as required go ahead with your repair but you will need to separate the two components to ensure both are cleaned properly — self cleaning flux is not a get out of jail free card ! Proper preparation is still essential but ti will clean minor and I do mean minor oxidation but it will not clean the oxidation and or fouling I would envisage on your failed joint.

*** "The pipe is 3/16 thin walled copper and goes into a fitting "

Just my thoughts John

[julian atkinsParticipant @julianatkins58923]

Hi Phil,

The easy answer is that any steam pipe on a loco should be silver soldered. I would never countenance soft soldering a steam pipe joint, in fact I always silver solder joints that are not subject to steam pressure as well.

This is 'best practice'.

I would suggest you depart from this at your peril.

'If a jobs worth doing'…

Soft soldered joints have no inherent strength.

Cheers,

Julian

Edited By julian atkins on 04/01/2017 23:31:40

[Keith HaleParticipant @keithhale68713]

Flux cored solder identical to comsol (trade name) is readily available ex-stock.Postage to Canada no problem. Look for CupSol.
http://www.cupalloys.co.uk/soft solders.

Regards
Keith
Declared interest – I used to own the company!

Edited By CuP Alloys 1 on 05/01/2017 15:24:18

[MWParticipant @mw27036]

Posted by julian atkins on 04/01/2017 23:30:31:

Hi Phil,

The easy answer is that any steam pipe on a loco should be silver soldered. I would never countenance soft soldering a steam pipe joint, in fact I always silver solder joints that are not subject to steam pressure as well.

Cheers,

Julian

So as a guide, what would you use soft solder for making? Bearing in mind we agree it shouldn't appear on a steam fitting.

Michael W

 

Edited By Michael-w on 05/01/2017 15:39:31

[Phil CashmanParticipant @philcashman42796]

Thank you to everyone who has responded with both information and with concerns and advice. Your help has been very much appreciated. With the information supplied by both Mark and Keith, I feel that I can proceed with acquiring the correct combination of solder and flux to do a proper job.

While I most certainly agree with Julian and Michael, I have had two of the most experienced Locomotive builders in my local area look at the problem. Both have seen no way to silver solder this fitting without causing irreparable damage to the boiler cladding. That cladding must be in place before soldering. I for one would love to be able to silver solder it and never have to worry about it again. The original builder was not able to silver solder it back in 1988 when he built it, but after these many years it did fail.

John has identified the setup perfectly and yes cleaning will be a concern because this non removable fitting was already soldered to a pipe. I am going to replace the pipe however with a new buildup all the way back to the injector.

These damn locomotives can be so much fun; or not!

A very grateful Phil

[Phil CashmanParticipant @philcashman42796]

Thank you very much Keith. I will be in contact with them directly.

Cheers,

Phil

[julian atkinsParticipant @julianatkins58923]

Phil,

Soft solder has no inherent strength. It is not suitable for joints under steam pressure you have described.

Take the cleading off and strip down and do a proper job with a silver soldered joint.

Cheers,

Julian

[Author]

Posts