Stefan,
>Isn't 6 minutes a bit long...
One common reflow profile calls for an initial gradual heat
(approx 2C/sec) up to 125C, then a slow increase (about 1C/sec) up to
175C, followed by rapid heating to soldering temp (220-250C) and a
10-15 sec dwell for full reflow. Altogether about 2.5 mins and then
cooling down. Co-incidentally, this sounds like it would be a good
profile for baking the ink also ;-?
I reckon with some insulation (there is none currently) it should
be achievable OK. Elektor recommend 100W+ per litre of oven. Mine is
800W and 4 litres so should comfortably exceed these requirements.
Stripping out most of the internal metalwork will also help.
>How do you plan to insulate it?
Some time ago while building a heat-treatment muffle, I bought a
large roll of refractory insulation, rather like rock-wool but good
for 1800C. I still have lots left, so I'll be using some for this
project.
>I may want to isolate at least the electronics...
Definitely!
Regards,
Philip.