Welding Tips and Tricks

http://www.weldingtipsandtricks.com/tig ... lding.html

Silicon bronze and Aluminum bronze vs ER70s-2
Surprising how weak a tig braze from one side can be....actually I guess not too surprised but a break test brings it home.
best of life to everyone here,

jody

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The etched picture seems to show a weld "nugget" with penetration into the base metal. Am I misreading this photo or was a weld etched sample put in video by mistake? Or does the braze metal etch like that.

I think we might be looking at the heat affected zone. The real bronze boundary is hidden by the yellow and red lines.


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vernd wrote:The etched picture seems to show a weld "nugget" with penetration into the base metal. Am I misreading this photo or was a weld etched sample put in video by mistake? Or does the braze metal etch like that.

Starting at 2:47 in, Jody states that the weld is on the left and the TIG braze on the right. If you extend a line down from the vertical plane on the left side, you'll see that the weld has penetrated into the root. The TIG braze on the right has not penetrated into the root.

Hope that helps,
Larry

I'll have to listen to the voice-over again: I >thought< I heard him say the base metal inadvertently melted and some braze filler was actually welded in.

I looked at the PDFs from the filler metal companies, and have some questions. Each PDF gives "weld" parameters, and I'm confused because the topic was brazing.

The filler metal charts also give an amperage range by tungsten width. In order to braze, do you match tungsten to the thickness of metal being brazed? I'm guessing the "1 amp per thousandth" rule would not apply since you only want to get the base material up to the melting temperature of the filler.

Or am I just way over-thinking this?

Sometimes the pores in the base metal will expand enough that the braze rod will fill in the pores and impregnate the base metal.

vernd wrote:The etched picture seems to show a weld "nugget" with penetration into the base metal. Am I misreading this photo or was a weld etched sample put in video by mistake? Or does the braze metal etch like that.

that was my bad... both nuggets are welds with slightly different penetration profiles. I meant to explain that the nugget on the right was a weld but would look like the lines drawn if it were a braze nugget. sorry about the oversight.

jody

What about using this on some lap joints on some 20ga for a fuel tank project on my motorcycle? Yes, I'm new at this, but am not terrible at a hobby level.