question for any certified welders

So my old man was telling me I shouldn't be welding chassis parts when the metal is below freezing. So yes or no?
I am welding with wirefeed flux core wire.

hes right. as you weld metal it creates a massive amount of heat, and emtal expands when its heated. The rest of the metal is freezing cold and you have a small condensed are of extreme heat. The cold weatehr outside and teh cold weather of the metal will create stress cracks in it. Some may not even be visible but the quality of your weld is greatly compromised

so warm it all up with a torch and life will be peachy?

You will need to preheat any metal you intend to weld outside in the winter cold...Though it is not recommended...

Unless you were doing Cold Metal Transfer MIG, then you could do whatever you wanted....But unfortunately it is designed for robots...

Okay, Dev what would be the best solution? Pre heat the metal with torch and the weld, and then keep heat on it like a small ceramic heater till the metal cools down to a normal temp.

Or maybe pre cut everything and wait till some warm temps, but how warm does it need to be?

room temperature liek 20ish is optimal, but if you really want to get er done now, then do as you said: pre heat tehn slowly cool it down

20-30 degrees would be fine...but the warmer the better imo....just less hassle!

So just like we have all said you can pre-heat it gradually, and then throw a weld on it, but do not force it to cool down with water or anything of the sort...Let things take their course...

Not sure what you are welding but if it is possible to transfer the heat around then do so, for example, start on the top, then bottom, then side to side (if welding something square) lame example I know, but you get the idea...

Once you do that then you should be good to go man! Honestly you shouldn't have any problems!

The only thing I would recommend is to get rid of the innershield if you can, but if you are using a small 110 or 220 then that is the only way you will get good penetration...

Just keep it clean, simple and you'll be fine!

well here is a short pass I made before I kicked the breaker. I'm stuck with the inner shield cause it's a 110v 110 or 120 amp welder. I don't remember the size but I've had it for 2 years now and with hobart wire it will melt 1/4" with ease. On this bead I have a nice blue ring about an inch or better from were the weld is on the backside so I know I'm getting penetration. But both pieces were warm too cause of just cutting and grinding.

anyways thanks for the tips guys, I will see what I can do to make the driveway a little warmer.

you might even want to post heat it if it is cooling to fast.