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[CuP AlloysParticipant @cupalloys]

By definition, the brazing process, of which silver soldering is a part, is carried out above the melting temperture of aluminium.

Soldering is carried out below the melting point of alumnium.

For an explaination of this fact find an appropriate historian!

As above, silver solder (silver brazing alloy) will not flow/adhere to tippex residues, graphite, or stainless steel if you use a flux unsuitable for brazing. eg the conventional low temp flux

Unless you use a specfic flux for soldering alumnium, then soft solder eg 60/40 tin/lead, 97/3 tin/copper, comsol will not adhere to aluminium

regards

keith

[Sub MandrelParticipant @submandrel]

Sorry to contradict the expert, but electricians solder can be made to adhere to aluminium sheet. Clean a patch with abrasive, cover it with a light oil (e.g. 3 in 1) heat it with a big soldering bit and melt a pool of solder into the hot oil. Use tip of iron (if iron clad over copper) or use a steel point to scratch at the aluminium if the solder is reluctant to bond.

Try it, you will be surprised how readily you can tin aluminium this way, as long as you can get enough heat into it without the oil catching light!

I've done this to make an earth connection to an aluminium box.

Neil

[KWILParticipant @kwil]

Sorry Neil, it is not a true contradiction, Keith said, unless you use a specific flux, flux deoxidises the surface and keeps the oxygen away.

What are you doing,? Spreading an oil = keeps the oxygen away, scratching the surface = removing the existing oxides, hence some form of adhesion/bonding.

[Ian S CParticipant @iansc]

Neil, been there done that, soldering earth wire onto radio chassis, think I found out about the method in Practical Wireless, back in the day when radio was my hobby. Ian S C

[Sub MandrelParticipant @submandrel]

Kwil

I wouldn't call 3-in-1 a specific flux for aluminium, though you are welcome to!

Neil

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