GraemeVW
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- 1,660
- Location
- Chesterfield
Decided to have a try at try and brazing a tooth on a cast iron gear.
Didn't go very well.
I'm using map gas, borax and these rods.
I'm aware I'm already going at this the hard way.
I am.encasing the gear in 50mm of vermiculite fire insulation board. I have an old drill as a spindle so i can hold the wheel vertical and rotate it.
To be fair, I think I got it hot enough. I heated the whole wheel, turning, making sure it was pretty even until it was at a point where I could stop rotating and quickly get it to glow red.
I then went to the area that needed repair and heated that area until the borax melted and went glassy.
I've done loads of silver soldering so this isn't new to me so far.
I then warmed the rod (also had borax on it) and poked it to the piece. It was sort of starting to want to stick. All signs to me I was getting close. Some braze melted off onto the piece so I kept playing it, even added more flux, but it wouldn't wet to the iron.
I was poking around with the rod and the piece was easily melting rod but it just kept balling up.
Ally experience tells me the base metal isn't got enough, but it was glowing orange/yellow at this point.
After maybe 45 mins of this i gave up.
I know there are better ways to braze this, but I need to build up a couple of teeth, then I'll never braze again, so reluctant to invest in loads of new stuff.
How i left it...
It looked even brighter in real life.
What are the group's thoughts?
Not enough heat?
Rubbish rods?
Borax not good enough for flux? (I have a borax cone you grind down in a dish, I've been using it on gold, silver, brass etc for many years)
It's possible I could use a friend's off acetelyne, bit it would be a pain as it's his professional work, if have to leave stuff there to cool, and I have 3 pieces to braze so would have to keep going back. Heat didnt seem to be the limiting factor though. I could get it hotter i think. But it didnt feelnlike it needed it. Im clueless about brazing though.
My gut instinct is it's either my prep (It's spotless but only ground out a tiny V in the middle) or its the flux.
Didn't go very well.
I'm using map gas, borax and these rods.
I'm aware I'm already going at this the hard way.
I am.encasing the gear in 50mm of vermiculite fire insulation board. I have an old drill as a spindle so i can hold the wheel vertical and rotate it.
To be fair, I think I got it hot enough. I heated the whole wheel, turning, making sure it was pretty even until it was at a point where I could stop rotating and quickly get it to glow red.
I then went to the area that needed repair and heated that area until the borax melted and went glassy.
I've done loads of silver soldering so this isn't new to me so far.
I then warmed the rod (also had borax on it) and poked it to the piece. It was sort of starting to want to stick. All signs to me I was getting close. Some braze melted off onto the piece so I kept playing it, even added more flux, but it wouldn't wet to the iron.
I was poking around with the rod and the piece was easily melting rod but it just kept balling up.
Ally experience tells me the base metal isn't got enough, but it was glowing orange/yellow at this point.
After maybe 45 mins of this i gave up.
I know there are better ways to braze this, but I need to build up a couple of teeth, then I'll never braze again, so reluctant to invest in loads of new stuff.
How i left it...
It looked even brighter in real life.
What are the group's thoughts?
Not enough heat?
Rubbish rods?
Borax not good enough for flux? (I have a borax cone you grind down in a dish, I've been using it on gold, silver, brass etc for many years)
It's possible I could use a friend's off acetelyne, bit it would be a pain as it's his professional work, if have to leave stuff there to cool, and I have 3 pieces to braze so would have to keep going back. Heat didnt seem to be the limiting factor though. I could get it hotter i think. But it didnt feelnlike it needed it. Im clueless about brazing though.
My gut instinct is it's either my prep (It's spotless but only ground out a tiny V in the middle) or its the flux.