Copper pipe soldering question

[glzahn]

I'm in the process of soldering copper pipe for my air system in the shop. I'm half way finished and I ran out of the larger solder made for soldering pipe.

It's Sunday and the big boxes will be closed by the time I drive to town, I'd like to finish this project tonight...so; can I use wire solder with rosin to finish the job or do I need to wait until tomorrow and get the lead free solder for pipe?

[K. L. McReynolds]

Use the on hand solder---clean each joint really well.

Lead free solder is intended for potable water soldering. I usually use rosin core for electrical, but for air systems it is fine.

[glzahn]

I thought so, but I figured I better ask. I do clean the joints thoroughly prior to soldering.

Thanks,

[geek2me]

glzahn said:

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I thought so, but I figured I better ask. I do clean the joints thoroughly prior to soldering.

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Rosin flux remains corrosive, even at room temperature - if you don't clean it AFTER soldering, it will eventually eat through the pipe. That's why electronic assemblies are washed after assembly and why modern "no clean" fluxes are used in electronic assembly rather than rosin core.

[GHR]

geek2me said:

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[blockquote]glzahn said:

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I thought so, but I figured I better ask. I do clean the joints thoroughly prior to soldering.

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Rosin flux remains corrosive, even at room temperature - if you don't clean it AFTER soldering, it will eventually eat through the pipe. That's why electronic assemblies are washed after assembly and why modern "no clean" fluxes are used in electronic assembly rather than rosin core.

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[/blockquote]

It is hard to clean the rosin from inside the pipe.

[AlanBienlein]

geek2me said:

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[blockquote]glzahn said:

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I thought so, but I figured I better ask. I do clean the joints thoroughly prior to soldering.

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Rosin flux remains corrosive, even at room temperature - if you don't clean it AFTER soldering, it will eventually eat through the pipe. That's why electronic assemblies are washed after assembly and why modern "no clean" fluxes are used in electronic assembly rather than rosin core.

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[/blockquote]

That's a new one on me . I would never use a solder for electronics that didn't specifically state that it was rosin core. There are solders out there for plumbing that contain flux that's acid based that should NEVER be used for electronics because it remains active and will corrode the joint.

[geek2me]

AlanBienlein said:

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I would never use a solder for electronics that didn't specifically state that it was rosin core. There are solders out there for plumbing that contain flux that's acid based that should NEVER be used for electronics because it remains active and will corrode the joint.

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Definitely should not use acid core solder. Can you even buy rosin core solder anymore? Haven't looked for it, but we stopped using it in industry in the mid 1990's. Rosin core is less chemically active at room temperature than acid core, so it acts more slowly, but is still corrosive and will eventually damage the soldered materials. In industry, the time required to clean off the flux increases cost, so "no clean" fluxes that have a flux that is inert at room temperature can eliminate the cleaning step.

[AlanBienlein]

I guess by.eventually you mean years as I have some projects that are 30 plus years old and no signs of corrosion and still work perfectly.

Amazon still sells it along with Radio Shack and Mouser.

[geek2me]

AlanBienlein said:

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I guess by.eventually you mean years as I have some projects that are 30 plus years old and no signs of corrosion and still work perfectly.

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Could be your climate - I am assuming it's fairly hot and dry there? Around here (midwest) some joints will fail within 10 years or so.

[blackhat]

You will use a lot of that solder doing pipe fittings. Air line doesn't have to be lead free. I would probably wait and buy a roll of plain 50/50 if you can find one. Well I wouldn't, I have 25 lb rolls of solder at hand, I would if I was you though. Nothing else at hand to keep you busy? BTW, buy another bottle of gas when you get solder.