[Elecraft] K2

[Don Wilhelm]

I have not used one of those irons yet, so I can't comment on those 
statements.
What I can say for certainty is that the component lead and solder pad 
must be heated sufficiently to allow the solder to flow onto both and 
out to a very thin (almost invisible) edge.

There is more to soldering than just melting the solder - it has to flow 
out onto both surfaces and adhere to both of them.  If the flow does not 
happen, you are just "pasting solder".  I am certain that can happen 
with any type of soldering iron.

The document that Josh referenced indicates that soldering may be done 
at a lower temperature with these irons, and that is OK - know your 
soldering tool and watch the solder flow as you work.

73,
Don W3FPR

On 6/2/2016 11:36 PM, Josh Fiden wrote:
> Sorry, that simply is not true. You don't understand how these Metcal, 
> newer Hakko (and other) irons work. Our production facility produces 
> thousands of through-hole boards per month. After testing the newer 
> soldering stations we immediately started replacing conventional 
> Weller WTCPT and Hakko 936 irons because both time per joint is faster 
> and temperature is more consistent as you move to the next joint.
>
> These newer designs intentionally use tips with low thermal mass, have 
> a fast control loop (rather than slow on/off cycling), and sense 
> temperature at the tip. Adjusting the iron temperature is normally not 
> required because the iron instantaneously provides more heat to 
> maintain the set temperature. If the rate is too slow, you would first 
> look at tip geometry to more efficiently transfer heat.
>
> This document describes the functional difference between conventional 
> vs new irons.
> http://www.eis-inc.com/Files/pdf/supplier_showcase_page_downloads/oki/Tech_Note_High_Throughput_With_SmarHeat.pdf 
>
>