What kind of LEDs are on the Arduino boards? Indicator ones/ onboard pin13 one.
Is there a special term for them other than SMD LED? (Searching for that turned up all shapes and sizes)
What "size" or "model" is used to refer to the ones on the Arduinos?
If you install the free version of Eagle, and you load the Eagle files for the Mega, then you can see the parts properties.
The LEDs come up as "CHIP-LED0805".
So an smd LED in an 0805 package.
Leo..
INTP:
What kind of LEDs are on the Arduino boards? Indicator ones/ onboard pin13 one.Is there a special term for them other than SMD LED? (Searching for that turned up all shapes and sizes)
What "size" or "model" is used to refer to the ones on the Arduinos?
The size is easy to measure with a caliper guage, most SMT components come in a standard set of sizes,
but there are always exceptions. There are literally 1000's of devices out there from dozens of manufacturers,
there is not enough room for markings on an SMT LED so you can't actually tell what part it actually is,
just guess from the size, colour and brightness.
Dimensions sre typically at the bottom of the datasheet. You have to pick a specific one and look up the datasheet.
Or pick a size, then select a part for its color and brightness at a certain current.
These are all 0805 size LEDs for example:
http://www.digikey.com/product-search/en/optoelectronics/led-indication-discrete/524729?k=led&k=&pkeyword=led&pv16=6&FV=fff40008%2Cfff801b9&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25
Was just looking for a place to start, in terms of what numbers mean what size and a brightness reference point.
How much current does the Arduino put through its 0805 smd leds?
The number is the size. 0805 (imperial) is 0.08" x 0.05".
It's metric equivalent is 2012 or 2 x 1.2 mm.
Google "SMD sizes", and go to images for charts.
Most Arduinos have a 1k resistor array for the LEDs, so about 3mA.
But I noticed that the ProMini uses 10k (~0.3mA).
Much better I think. Small LEDs can be like lasers.
So bright that you can't see the writing on the board next to it.
Leo..
The number is the size. 0805 (imperial) is 0.08" x 0.05".
Really ? Who knew ? 
Ordered some 1206 leds, figured a little bigger is better since I'll be hand soldering them.
Now the question is to go at it with traditional rosin core solder or pick up some 'solder paste'.
If I dab a little solder from the rosin core solder wire onto my soldering tip, does any of that flux make it onto the surfaces to clean/wet or does it cook off pretty quickly?
INTP:
If I dab a little solder from the rosin core solder wire onto my soldering tip, does any of that flux make it onto the surfaces to clean/wet or does it cook off pretty quickly?
Don't put solder directly on the tip of a soldering iron, unless you want to pre-tin the tip and clean/wipe it off.
Rosin is needed to solder and it will quickly burns off, making the tin useless.
Heat one of the pads with the tip, and apply a tiny amount of solder where the tip meets the pad.
Quickly, so that there is still rosin left on the pad.
Position the LED with tweezers, and tack that side of the LED.
When happy with it's position, solder the other side of the LED first. Then re-solder the first pad.
Solder quickly (<3seconds), and wait 10 seconds between (re-)soldering.
Leo..