Silver soldering contradiction

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Or [alternatively, and perhaps more typically for small jobs] the solder is included within the joint area, either as 'paillons' or as rings of wire ... and the flow comes out to the edge.

MichaelG.

Therein lies the problem, quite likely.

If you beat or press a domed/flanged boiler end out of flat copper plate and make it a tight fit in the piece of copper pipe that forms the main boiler shell, does that mean it's a "no gap" fit? Or does it mean the end piece is a tight fit on the three points around the OD that are in contact with the ID of the copper pipe and there is possibly a one or two thou gap throughout the rest of the joint?

To mate two pieces of metal together with gaps of less than a thou or so often requires engineers' blue, scrapers, surface plates and the like. Would bits of copper sheeting and pipe as formed stand up as "no gap" fits if checked with engineers blue etc to a similar standard?

And if you prep the copper surfaces with emery paper, do the myriad surface scratches created constitute a "gap", being they could be a thou deep in each of the two pieces?

Edited By Hopper on 13/04/2018 08:48:20

Edited By Hopper on 13/04/2018 08:48:59

The danger now with this topic is that people who are new to silver soldering will read this and assume that they are obliged to make provision for a 'gap' when preparing parts to allow for the solder ....In actual working practice one can forget about the 'gap' when making up parts and components by hand methods (and most machining too) as there is every chance that solder WILL flow into joints...and the solder WILL NOT fill any gaps.....

Again;..parts must be a good close fit......the parts MUST be clean of impurities.........the joint MUST be hot enough (red, 'glowing' before solder is applied.

BEWARE of;....impurities in fuel or torch that spoil cleanliness before temperature is reached......lack of heat due to poor torch choice, poor heating technique......touching the parts with bare hands after cleaning........not dissolving flux, such as Borax, sufficiently before application so that the undisssolved 'grains' can't run into the joint.

Edited By Bob Stevenson on 13/04/2018 15:41:13

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Sorry, Bob ... I must beg to differ !!

If those people actually READ what has been written, I think they will be able to make a reasonably well-informed judgement.

MichaelG.

Sam,

Did you read the piece that I quoted from, earlier ?

MichaelG.

Guilty as charged, Michael

I knew I read it somewhere.

Is this what happens when we get old?

Keep smiling,

Sam

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You're doing fine, Sam

MichaelG.

This is what I would use if using filler rod.

For a butt joint, I would interpret that to mean lightly clamped, VE !?

Does this help those who have never seen or heard of H7/j6 ?

https://en.wikipedia.org/wiki/Engineering_tolerance 

'Go to the back of the class, Sam!"

Edited By Sam Stones on 14/04/2018 20:37:26