Silver Soldering

[JssParticipant @jss]

Am I being over optimistic here?

This a big end bearing I’m trying to repair. I’ve bored it out and am hoping to put a leaded bronze liner in it prior to final boring and scraping in. I’m proposing to silver solder the parts together. I have the means to apply sufficient, uniform heat (oxy/fuel torch and motorised turntable). Having applied suitable flux to the surfaces and fed the solder in from one side, will the solder penetrate right across the 2ins to the other side? If not and I turn it over to feed from the other side will trapped flux prevent full penetration?

I have bought Silver-flow 55 solder which the seller said is suitable for most engineering metals (not aluminium), but read somewhere that leaded bronze requires a special solder so am not sure now. Does anyone out there have experience in soldering leaded bronze?

[Andrew CrowParticipant @andrewcrow91475]

I would have thought that silver soldering temperature might be a bit high for leaded bronze, maybe soft soldering would be sufficient for the use that the bearing will have have.

Andy

[duncan webster 1Participant @duncanwebster1]

Leaded bronze (SAE 660 probably) can be silver soldered, but not as easily as unleaded because the lead contaminates the flux. As Andrew says, I’d use soft solder or even epoxy. The joint doesn’t need much strength,  it’s only preventing the bearing turning

[Bill PhinnParticipant @billphinn90025]

Whether you decide to use silver solder or soft solder, you could sweat solder the concavities of the two halves first, pickle, smooth down any lumps, flux again, keep the three pieces of the assembly lightly pressed together, and heat until the solder visibly re-melts.

John Mills on his Doubleboost channel has done this successfully several times with soft solder on bigger pieces of bronze than you are dealing with.

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