I'm going to start a build. But my cheap harbor freight soder iron is crap!!! What kind of specs should I look for when buying a new soder iron? Should it be temp adjustable? And how many watts ?

I use/d
- 60W cheap soldering iron for heavy weight soldering - 12awg wires etc
- 25W very cheap soldering iron for pretty much anything else (I changed tips VERY frequently because they burned out quickly) - that one died after 1.5 years of use and that lead me to buy:
- soldering station with a hot air gun, had to learn regulating the temp and to change tips depending on the task, but it heats up momentarily and I'm very satisfied with it. Having a regulated hot air gun is also great. It's very similar to this: https://kamami.pl/stacje-lutownicze/2350...a-60w.html

But before my 25W died, I was able to do everything except SMD desoldering so... choice pretty much depends on what you want to do really.

Antex 18W G/3U: http://products.mmnewman.com/antex-solde...ering-iron
You'll want to pick up some smaller tips than the one that comes with it (also at mmnewman).

Not cheap, but this is the best soldering iron I have ever used (I have about 10). Beware of cheap clones (found on eBay and elsewhere).

I like to have the possibility to change the temperature so you can use it for multiple tasks.
I'm using now something like this and it's 48 watt:

I was just yesterday given a butane soldering iron, sadly its about 15 years old and the gas line to the nib is blocked so it doesn't work, hopefully I can fix it... The gas flow can be regulated and the tips changed for use with fine work or heavier wire/solder. Refilled with lighter gas, heats up in seconds and usable anywhere. Man I have just sold it to myself all over again, I really need to fix it...

I've used cheapie pen-type irons for decades, and didn't realize what I was missing until I got an adjustable station. Been using the $20 Yihua 936 from Hobbyking for a year and highly recommend it. I think it's a Hakko knockoff, but works very well for all my projects. You can't go wrong for the price, but you will need to get a $5 pack of misc. tips, since it only comes with a very fine one, which only works well for small cconnections. Good luck on your project!