Aoyue 857A++ 2.4mm nozzle fit problem? Or is it?

[shadewind]

I got a hot air station recently and I've been trying out different nozzles a bit. All nozzles work fine except for the 2.4 mm one. I've tried desoldering some small resistors (0603) but it takes a very long time. I've got the temperature set to 350 C and the airflow on the default setting. I'm suspecting the culprit might be that the nozzle seems to fit a little worse than other nozzles which leads to some of the air leaking out the sides and instead blowing back on my hand (not so warm that it's uncomfortable, but I can feel it). But maybe it's just the very small hole in the nozzle which forces the air to escape on the sides? Or maybe the problem is simply that the nozzle is too small to heat the area the resistor and the area around it effectively?

Anyway... has someone else experienced this with small nozzles in this or other stations? Maybe small nozzles are simply inappropriate for most work? What sizes do you usually use?

[Bored@Work]

5 mm is a good size. Smaller nozzles create a problem for the pumps in such cheap hot air stations. The small nozzle means pressure is building up in the system (as evident by your observation that you have some 'blow out'), and the cheap pumps can't work well against that pressure - reducing the maximum airflow you can get out.

Fixing your 'blow out' should increase the airflow a little bit, but won't make a huge difference. These nozzles are typically of rather soft material, so you should be able to bend the 2.4 mm nozzle into some better shape to sit a little bit tighter. Also check if you have other leakages in the air system. But see above.

350 °C is also a little bit low. On a professional, well regulated station one would typically start with 400 °C, and 20 l/minute air flow. But scales, displays and regulations on these cheap hot air stations are such that what is shown on the displays or scales is not what is going on. Especially the airflow is not regulated.

[shadewind]

Thanks for the great answer. I suppose I could bend the small nozzle into shape but it seemed to me that it worked poorly regardless of airflow which tells me that it's probably more of a temperature problem. As always, you get what you pay for, of course, but I feel that this station could be a lot worse. At least it's rather solidly built and has no electrical safety issues.