Advice needed on Starting the puddle

[NGT]

I would like to ask what you guys do when you start your puddle.
In the first few seconds it looks like it stays on top of the metal with poor penetration, and then levels and widens as heat increases. I noticed this somewhat is happening again, when i was restarting the bead after a rod change.
I also noticed that the metal temprature chases my puddle and after some time my 2.5mm mild steel pipe becomes well red around the puddle and i was speeding up so i can input less heat so no holes. I also tried smaller rod and bigger rods. Funny thing is with the big rod, i can put lots of metal into the area so it becomes like a heatsink for my weld puddle during welding
! So i got all these observations in my head and i am very confused !! Small rod ? Big rod ? Lots of amperage and quick ? Low amperage and humps ? Avoiding holes while getting penetration plus all the above !
Any advice ??

PS: Thick plate is more stable but it happens there too.

[Scott Young]

this may be a silly question, but how cold is it there? i have welded on equipment that was frozen, and it did what you described. i fixed it by preheating it with a torch.

[injun joe]

well a rule of thumb is to never use a rod bigger than the base metal which i know is very hard to do like with sheet metal. and the to fix the poor penetration preheat the beginning of the work piece. and the bigger rod should actually make more heat when properly used. need specifics:confused:

[NGT]

My room temp is about 20C. And i am a noob, start to MMA prior to TIG'ING

I was butt welding 90 deegree steampipe bends mild 2.5mm thickness @ about 60-70 Amps with 2.5mm Rod, NO v groove on the butt, (i love the groove because hot or cold the weld just seats there like a good boy).
Maby i am using too much current, i will test that tommorow.
Welding on a flat 2.5mm plate was much easier and tidier i could change the amps the diameter of the electrode everything was good, but this round butt weld is really weird ! Maby the puddle drips at the edges of each pass, i do 1/4 of the butt joint at a time so i my puddle doesnt drip

[NGT]

Ok looking at the stick welding tips i guess i might be running a little higher amperage, i have a very short arc (sometimes i was dipping the rod in the puddle !!) and i go a little fast because of the high amperage. Plus the weld is not in horizontal position but moving on a round butt seam. I am guessing the biggest error was the short arc because i was pursuing to get as close as possible as a consequence when the metal heat was low the puddle formed a narrow bead. I'll do some more testing tommorow i guess ! http://www.hobartwelders.com/weldtalk/attachment.php?attachmentid=25757&stc=1&d=1204761475