Learning to braze

[joco-nz]

... the other thing to engage in is welding warm up just before starting on the real project. You want to get the mind and muscles working in sync before attacking a work piece with dozens of hours in it. This would apply no matter the process, be it silver solder, brazing, oxy welding, stick or flux core. Get your machine and mind dialed in before hitting the real stuff.

This is SOO TRUE! :thumbup:

Something I have finally learned, especially for fiddly processes like Aluminium welding or where you need to be able to keep a point a long way from your hands under mm level control i.e. a good old Stinger.
I get some scrap and run a few beads to get my mojo back in the game, get the muscle memory going again and just to relax. Brazing or welding when you are tense is going to end in a screw up.
When I look back over time at how I was positioned and feeling when I ran a stick bead and had the slag peeling off on its own or got a nice "stack of dimes" TIG weld look I was in a comfortable, well balanced position, breathing evenly with no muscles tensed up through the shoulders and arms. It probably sounds a bit "mind and body is one Grasshopper" but seriously it really does make a difference.

Cheers,
J.

 

[XD351]

MRA ,
If you are new to oxy acetylene you need to go back to the basics like regulator settings because you must be careful with the acetylene setting - it has a strict maximum setting for pressure that must be adhered to .
Once you have that right you need to understand the setting of the flame - oxidising, neutral and carburising.
Once you understand what you need there it is time to set up for some practise , 3mm ( 1/8) x 20mm (3/4) black mild steel flat bar pieces cleaned up with a grinder or linisher to remove the mill scale and set up some lap joints .
I suggest this because steel is easier and small parts don't need a big tip so gas economy is good , i won't suggest a red heat to aim for because glowing hot steel looks different under different light conditions so what i use may look to cold or hot in your shop depending on the light -better to start too cold and work your way up in heat slowly but a dull red would be a good starting point .
I would bin the flashback arrestors you have and buy new ones - they are there for a reason and a safety item and i would rather have new units that i know will work as intended .

 

[XD351]

This is SOO TRUE! :thumbup:

Something I have finally learned, especially for fiddly processes like Aluminium welding or where you need to be able to keep a point a long way from your hands under mm level control i.e. a good old Stinger.
I get some scrap and run a few beads to get my mojo back in the game, get the muscle memory going again and just to relax. Brazing or welding when you are tense is going to end in a screw up.
When I look back over time at how I was positioned and feeling when I ran a stick bead and had the slag peeling off on its own or got a nice "stack of dimes" TIG weld look I was in a comfortable, well balanced position, breathing evenly with no muscles tensed up through the shoulders and arms. It probably sounds a bit "mind and body is one Grasshopper" but seriously it really does make a difference.

Cheers,
J.

100% spot on !
I had some fantastic teachers at tech college and they taught me a few mantras with welding .
Cleanliness - you can't get metal too clean and you want bare clean parent metal so any mill scale , oxides , paint or any other coatings must come off.
Set up - this is 75% of what determines a good weld , if your set up is crap so will the weld be .
Comfort and steadiness- get comfortable and lean on anything you can to steady yourself , if you have ever tried doing a vertical up weld free standing then tried leaning on something or sitting down you will know what i mean !
I used to take this to the extreme at tech - i used to drag the bench around so i could rest my back in the corner of the room and put one foot up on the welder and the other on the shelf under the bench , this pushed me back into the corner so i couldn't wobble and it sure made doing vertical up welds easier - Sure out in industry you can't always do this but at home you can !
If you watch really good welders you will notice they don't rush too much and they have their little tricks to speed up the cleaning and set up so they can concentrate on the weld , if you watch Bob Moffat on weld.com and watch his head as he welds you will notice little the movements he makes to adjust his view of the weld pool - that is all he is focusing on and not worrying if the set up is ok or the job clean .