From experience what wire would be recommended to use for ECU work? I assume multicore for more flexibility? But what size?

And additionally what methods do you guys use for tiny circular hollow contact pads. Do you even try to tin them or go straight at it with the flux and 60/40 solder?

And around what temp do you set your iron to?

Sorry for all the questions, normally I have no issues soldering but found today to be quite a challenge.

I was messing with a BMW for boot mode that required some resistors and had a real hard time with some of the thicker single core that I have. It was difficult to get the cable to take to one of the tiny contacts too.

i use .022" solder and kingbo flux.
350/360 deg c for regular work.
30awg wire.
hot air is great.

Nice work on the RS6 C167 thats impressive.
Think I need to buy an air station too.

So here is the solder I just ordered which should be suitable? The stuff I had before is lead free and a nightmare.

It's 60/40 tin/lead
http://www.amazon.co.uk/gp/aw/d/B002L5Y8R8/ref=mp_s_a_1_2?qid=1385163908&sr=8-2&pi=AC_SX110_SY165

This is the flux pen I currently have which is a no clean rosin.
http://item.mobileweb.ebay.co.uk/viewitem?itemId=130962877320&cmd=VIDESC

And I'm stuck with what wire to use. What diameter core?

The picture does not directly relate to the ECU I was doing boot mode on but I'm on my phone and was the first I could find that had the circular hollow pads I speak of.

i guess to answer your question, as opposed to a picture, IF i was going to solder to a via like that i would use an iron. i only really use hot air on smd type stuff. resistors, leds, that type of stuff, small ic's, mosfets as well.

all you need to do is flux the board, and touch the iron and solder to the point. it should flow right on there assuming its exposed. then just lay the wire on it and touch the iron to it. pretty painless in theory.

but if this type of work is something youve never really done before, you NEED to practice on a dead board of some sort or something you dont mind breaking. because you are going to brick something sooner or later.

That's some impressive work right there.

I was thinking of the jig idea but my frame will not facilitate it as the actual frame is in the way no matter how I position the ECU.

Think I need to get a little more creative :-)

Thanks to both for your replies and guidance