Tip distance to material

[BigPoser]

This may be a dumb question, but I see people doing different things when brazing which prompted this question.

How far does the tip of the torch need to be to the material being brazed for it to be effective?

I see some that damn near put the tip on the metal, where others are 4-6" away. Are the people putting the torch right next to the material doing something different than those that keep it farther away?

Thanks in advance.

[steve garro]

How far does the tip of the torch need to be to the material being brazed for it to be effective?



Thanks in advance.

Depends on how high you turn it

- Garro.

[Andrew R Stewart]

I think it depends of what they are trying to do. Independent of personal style the laws of heat transfer remains the same. Tiny flames don't put out as much energy as large ones do, either by adjusting the flow or the tip size. Any flame held closer will heat a smaller area faster then if held further away. The longer a flame is held in one spot the hotter it will get. Pretty simple:) Of course saying it don't make it happen.

When I braze w/ silver I tend to use a smaller tip, less flow/smaller flame and position the flame off the work an inch or two. For braze ons less flame, for lugs more flame.

With bronze the flame is bigger/higher energy and I'll get a bit closer to the work as well. If I'm lugging it the flame will be biggest. For fillets I'll sometimes do both root flow and fillet in one pass so the flame is med sized and fairly close to the work. Other times I'll flow the root with a med/big flame then go back to build the fillet and turn the flame down and get pretty close. As close as the flame's inner cone tip is almost touching the work.

This is why you practice, to find what happens when you do this or that. As you refine your skills, read and reaction, you'll settle into what works for you. The more experience you have the faster you can become. Andy

[Michael Gordon]

Use the force Luke...

There are times when I am brazing a joint that I need to being the flame closer, and others when I need to back it off. Heat can be controlled not only by the size of the flame, but also with the distance of the flame to the work.

While fiddling with the brazing rod in one hand, don't lose site of what your torch hand is doing at the same time.

[Eric Estlund]

The cone zone temp will be based on fuel gas. The cone size (length) will be determained by flow rate and tip size. How the cone size and zone are being utilized will depend on the operator, material and filler.