Hello everybody,

I'm Giang. I am reading some documents and confused with 2T/4T welding, hot/cold start. Could you make clear about that.
Thanks you very much!:)

Hello Giang , 2T and 4T is used on some TIG machines to describe how the machine is started , for example 2T mode is simply press the switch for on and release to turn it off where as 4T is a bit more complicated in that you press once for on and press again for off and will also have a ramp up and ramp down feature .
maybe some one can explain it better than I as I have found it to be different on different brands of machine as well .
Hot and cold start is how where a machine starts for example a cold start setting will start with low amps (cold ) and ramp up to your set working amps where as hot start will either start at your set working amps (hot) or may even start at a higher setting and ramp down to your set working amps . What you use will depend on the type of welding your doing for example I would not use a cold start with manual (stick) welding.

Hope this helps a bit

Many thanks to Metalmark,
I think that you have given the correct explanation about hot/cold starts.
But I am not sure about the 2T/4T welding. I think they relate to cycle time of a current (often 50/60 Hz), but I could not found the right definitions.

Progiangbk@gmail.com

you are right in that it has nothing too do with starting conditions , it also has nothing to do with cycle times or frequency etc . What it is is a mode of how you want the on-off switch to behave , I personally like to push a button on and hold it on to weld and to stop release it , other people like to push to start and push to stop , it is like the latching feature on some MIG welders . 50 or 60hz usually only refers to AC input frequency (the US is 60Hz and here in Australia it is 50Hz ) and has nothing to do with welding current or cycle times

Thanks you very much,
I have gotten your idea. You give me a lot of useful information.
On the same occasion, I know MIG is acronym of Metal Inert Gas welding and TIG stands for Tungsten Inert Gas welding, but I have never used any welding machine, could you briefly tell me how to operate one MIG and one TIG welding ( steps from preparation to the end of the process).
Progiangbk@gmail.com

To explain to you how to use either MIG or TIG would fill up a book , basic welding is not that hard to learn but it is a"hands on" process and it takes a lot of practice , a steady hand and good eye sight , I am not to sure where in the world you are but if you really wish to learn how to weld see if there are any courses available in your area .

Thank for your recommendation. I just want to know basic definition of the problems which help me in documents translation. Maybe I will fine some books or article about them.
Anyway, thank so much for!