Don Foreman wrote:

The key here is gas velocity, set your pressure for whatever torch you
use to provide a low-velocity flame. 4 psi is a pretty good
guideline.

Sorry for dropping in. But this puzzles me a bit.
I mostly have my Oxy-regulater at 2.5 bar (36 psi) and the Ace-regulator
at 0.5bar (7 psi). That is what I have learned and I only change that
setting when I need some wired setting.
The kind of flame I want is regulated at the torch.
If I want a soft flame, I use a big tip and throttle Oxy and Ace down.
If I want a sharp flame, litte tip, oxy fully opened and adjust flame
with ace.

And also, I got better results when aluminium welding with a sharp
flame. That is because I can keep the puddle smaller. Al tends to have a
big (easily huge :-)) puddle because of the good conductivity.

And, while we are at Al welding: Preheat the work. Heat it up until a
wooden stick drawn over the part is dropping little sparks. It then has
the right temperature for OA-welding.

Heating up (to about 100°C) helps getting better first few inches when
MIG-welding Al.


Nick
--
Motor Modelle // Engine Models
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