Welding experts

[pasbogdan]

I need to get some help with mig welding maybe some documentation about techniques.
Due to rollcage manufacturing i am very concerned about good penetration and welding aspect was not a big important task for me but i will need to get this right also.
My mig is the little in the big class,a 30 to 200 amp,230/400v feed.I worked with one the same before user had it for 5 years and had no problems with it that is why i bought it.I know that it is not a miller or lincoln but after getting all variants in mind i payed 700 eur for it instead of getting 300 for a small one or 1000+for anything else(maybe we will get a tool discution also)
Anyway:
I did its first test on 2 pcs of 2mm steel with amp set to 2'nd lowest position and wire feed according to it.As you can see in the pictures where welding starts aspect is bad(and on rollcages i can not get it bad because if i get another weld to enshure penetration aspect will be to bad)
Also penetration is bad at the begining.After that it gets good,even a little to high on some places and to high at the end.
Where am i wrong when starting?I got shure that gas was on my pistol,i was getting air out.
I was using "e" travel method
What about argon-carbon dioxide mix bottle price in your country?Here a big tube costs about 70 eur and because i do not have my own tube in the first month i will pay rent for it 15 eur,if in the 2'nd month i do not refill it will be 30 eur and if in the 3 rd month i also do not refill it will be 60 eur staying there for the rest of period of rent .If i empty it in the first month and recharge i will pay recharging and little tax for the first month of rent.I need to get my own tube...

[Error404]

torch speed is inconsistent perhaps?
Also how was the part fit-up before you started? I always try for a 1mm or less gap between parts to be welded

[pasbogdan]

So you are saying that at the beginning of the weld i tend to get to fast ahead and only after that i stabilise my travel?Should try starting with little speed and holding the nozzle closer to the weld(shorten the stickout)to avoid high buildup weld and after that starting with normal travel?
Looking closer i found out another mistake:my angle was not 45 so heat and more weld buildup on the bottom plate.But that fillet weld is the simplest weld that can be done.What about other types of welding,positions,vertical weld etc?Do you have some proper documentation about welding techniques?

[ryster]

Yes Pre heat slightly . Make sure all tubes etc are scolloped to correct angles and fit nicely , but slight shanfer end off tube ( not to a point ) And leave a gap when tacing up .. Make sure matierals are clean !

u could also back purge ( fill the tubes with the same gas that u are using on the mig welder) ,But on your cage u have to drill a hole where the joints are. So the gas can fill the hole cage in one hit. , tape up all tacked joints using metal ducking tape ! So not vent the gas ... U will defo get best result this way coz there will be less inpureaties in the weld , it end up being welded from both side .

A little more work though .

Another tip is back step ! Basically once you are all tacked up and ready to weld . Weld one joint then move to an other joint one the opposite side of the cage And do another joint and so on Don't put to much. Heat in one place . This will help with distortion .

Do practice joint first to set welder up don't set wire speed to fast !!

[ryster]

Hold nozzle about 10/12 mm away from work peace .

Mig vertical will look messy . U will get to much heat and blow hole in work.

U could vertical weld with mig half tidy by pulsing the trigger. :
Do a tack then move up a 3rd of the tack and do another and so on . Don't do down wards welds very poor penetration

Or put a root run in with mig or even better a tig and a caping run over the top.

Hope this helps or as it just gone right over ur head ? Lol

[stocious]

get a mask that tint's on arcing, my left eye is fooxed over mig welding and not taking care of my eyes. auto tint mask's will make starting your weld much easier.

[pasbogdan]

On vertical welding i found out that going downhill special when there is a little gap between parts to be welded staying in front of the puddle with gun angled up about 60-70 degree will get a nice fill.Also staying a little more time on the margins of "c"travel and quick pass to the middle section will get penetration to sides also,not only fill the gap.

[pasbogdan]

get a mask that tint's on arcing, my left eye is fooxed over mig welding and not taking care of my eyes. auto tint mask's will make starting your weld much easier.

I am using autodarking mask,this is how i can see what i am doing.With the other type all i saw was a flame and just a little of what was happening there.

[ryster]

I have a good book on pipe welding technique s. I m not sure of the name now tho. Have alook on amazon these really go books on there . I used to have a few pipe codes . But they have run out now .

[pasbogdan]

If you find the title please share.Tubing will be an interesting thing to see.Special on sharp angles where gun does not get into and welding is done with a long stickout
Thank you for info,please continue giving details.

[stocious]

im sorry i never took the oppertunity to do a certified course on it during my apprenticship. offered free. 400/500 sheets now. looking at picking up a tig soon

[ryster]

Yes. At low heats it's ok on say a gate etc but on a roll cage u want fall penertrasion really A down wards weld will look ok but it will be a weak point try not to do it .. Do a test

[pasbogdan]

Good price,i was asked 1000 eur.
Ryster:
What kind of travel are you using uphill?Do you go for z,half circle or e?How do you keep puddle flat not comming down?

[ryster]

I think it some think like pipe work systems. Not sure tho . Practice is the key !!

Another tip to think about is if there is goin to be joints u can't get in situ and you can do then before hand on the bench before hand it my save time.

Make a

[ryster]

Sorry . Plan . Are u trying continous up hill Or pulse Like I said be before