Hi,
Very well said.
In addition, the heat transferred to the joint has nothing to do with the power rating either. If you have a 50 watt that poorly transfers heat, you can have a 100 watt that poorly transfers heat, etc., but the heating element will really be 50 and 100 watts respectively, regardless of how it transfers heat.
The rule here is we dont say something doesnt work because there are ghost variables that we cant explain. If we cant explain them then they cant explain them either.
When it comes to heating, it's one of the simplest concepts on earth. If you have 20 watts of heating you have 20 watts of heating, and if you have 50 watts of heating you have 50 watts of heating power, period. There's no wiggle room here especially since soldering irons have been given ratings since the stone age.
I know people sometimes jump to the "possible variables" when something doesnt work right, but the reason we are here today is because we want to explain all the variables and come to a conclusion. For this we can, and state that the irons are being over rated by the sellers.
Also, and this really nails it, some irons sold as 60 watts come with elements stamped "50 watt" right on the element itself. Now that wouldnt be too bad i guess, 50 vs 60, but unfortunately that "50 watts" is also untrue because the element is still only 36 watts !
Maybe the better manufacturers put out some quality stuff with the right ratings, but some of these knock offs clearly dont. I havent been able to test any really good units unfortunately, only some cheaper ones. One was about $150 and the other was about 70 or 80 dollars (USD).