my first true mig welds

[dan s]

Yesterday i finally stopped by my local gas distributor and picked up a tank of C25. I have been using flux core wire since i picked up my welder (black Friday impulse buy ).

One thing is for sure I'm never going back to flux core unless i need to weld outside.

the following are my newbie (less than 6 hours of stick time) attempts at MIG welding.

My beads still aren't the most consistent.



A perpendicular cut through the bead to check penetration.



This butt joint was 1/8" bar no bevel or gap (my welder is only 110v), i still have an issue with little pin sized gaps.




Is there a simple formula to calculate bevel and gap, for a given ipm/amps?

[Davek0974]

Looks good, check out here...

http://www.mig-welding.co.uk/

lots of help and calculators there.

Dave

[Your Old Dog]

One thing is for sure I'm never going back to flux core unless i need to weld outside.

I was told I'd never go back to fluxcore after trying gas and they were right. Someone here told me that. I guess the fluxcore still works outside in gale-force winds I never weld outside.

[torker]

Your weld...not bad. Try to steady it up so you avoid the "sawteeth" on the edges.
Destructive (bending) testing would show a fracture along that area.
With a light welder...don't walk it from side to side (weave)as much...that'll avoid the saw teeth issue.
The "T" joint...in the position shown is a horizontal weld. Don't weave in this position.
Run nice straight beads. You want a wider fillet...do multi pass welds..
If you want a 100% weld your bevel must come to a point. You will also want good preheat...especially for a light machine.
"Rule of Thumb... Fillet size (for that "T" joint) should equal half of the base metal thickness.
If you want I could post some pics of a heavy multi pass weld on a T joint.
Keep at it!
Russ

[dan s]

Torker,

The pics would be interesting to see...

Do any texts exist that cover the different set-ups?

All the books i have checked out of the local library (and university) are either child simplistic, or studies on ways of minimizing costs in a production environment.

I haven't been able to find anything that talks about bevel, root gap size, bead laying etc, in any kind of systematic way.

these two videos are pretty interesting.
http://www.youtube.com/watch?v=7AZXG5WVw6E
http://www.youtube.com/watch?v=HL2H79cgDuo

[oldtiffie]

Torker,

The pics would be interesting to see...

Do any texts exist that cover the different set-ups?

All the books i have checked out of the local library (and university) are either child simplistic, or studies on ways of minimizing costs in a production environment.

I haven't been able to find anything that talks about bevel, root gap size, bead laying etc, in any kind of systematic way.

these two videos are pretty interesting.
http://www.youtube.com/watch?v=7AZXG5WVw6E
http://www.youtube.com/watch?v=HL2H79cgDuo

Thanks Dan.

That's good work that would do for most folks.

To see it better, sand/grind/polish some of those faces in your pics and acid-etch them (almost any "acid" will do) and you will see the changes in colour and boundaries that will tell you how it went. The "miss" or "inclusions" at the roots will do for most jobs.

Torker is pretty well the subject matter expert here and really knows his stuff and really goes out of his way to help - which he is very good at.

A lot of reading, a lot of practice, more reading, more practice etc.

Anyway, some of these links should help.

http://www.thefabricator.com/ArcWeld...le.cfm?ID=1083

http://www.millerwelds.com/education...pamphlets.html

http://www.millerwelds.com/pdf/mig_handbook.pdf

http://www.mig-welding.co.uk/tutorial.htm

[macona]

Dont weave at all. Unless you have a tractor with a weaving feature. Most people can not do it with enough repeatably to do it consistently.

http://www.weldreality.com

[boslab]

the right hand flank showed a bit of undercut, watch the amps, you dont realy need to weave more than the width of the weld unless your trying to plug a big gap, then that wouldent realy be a good idea. on the whole a brilliant first effort, mine looked like seagull **** splatered on a windsheild according to my instructor!
keep at it [you can try running a chalk along the weld it does help, reflects uv etc and gives you some reference point in an otherwise dark world]
regards
mark

[Alistair Hosie]

That's a gold star for your first attempt . I tend to not see the workpiece or the nozzle. I have an automatic helmet should I adjust it more so as I can see better what I am doing that's definitely my problem any advice welcome.Alistair

[torker]

Weaving is entirely acceptable in most industries...in the flat, verticle and overhead positions.....never in horizontal.