Thread: Welding Critique: SS 2mm Thick MIG

Looks damned fine to me.

Nice job Justin - so is this done with a string of on/off pulses or a continuous run? How'd the back of the weld turn out? - clean? Cheers - Mick

For a welding trolley? Looks great.
For anything more structural, it's just a bunch of tacks.

Originally Posted by WelderMick

Nice job Justin - so is this done with a string of on/off pulses or a continuous run? How'd the back of the weld turn out? - clean? Cheers - Mick

It's a series of tacks but each tack blends in with the next.

Basically I weld, STOP, wait for the helmet to un-shade, and weld again.
Just keep doing this over and over until it's done.

It's a corner weld so once welded has full penetration.

Back of the weld due to the copper looks really good and like it's been done professionally.

Cheers

Justin

Originally Posted by distractor

For a welding trolley? Looks great.
For anything more structural, it's just a bunch of tacks.

That's probably true.

I can do full penetration welds no problem but being MIG they are just nowhere as neat as a TIG for decorative purposes.

I noticed at the 4x4 and camping show all the stainless water tanks are MIG welded and they don't pickle the welds either.

Could easily run a bead but didn't want to grind or finish it in anyway.

Cheers

Justin

Originally Posted by Jarh73

That's probably true.

I can do full penetration welds no problem but being MIG they are just nowhere as neat as a TIG for decorative purposes.

I noticed at the 4x4 and camping show all the stainless water tanks are MIG welded and they don't pickle the welds either.

Could easily run a bead but didn't want to grind or finish it in anyway.

Cheers

Justin

I really don't want to sound negative, so I hope you take this in the spirit it is intended.
Why do you feel that if you were to run a bead it would take any more finishing than your series of tacks, (as it has been described)?
My suggestion would be to have a bit of a play with some scrap ss and practice setting your voltage and wirespeed. Believe me you will be able to lay down the sweetest little corner to corner joint you have ever seen. I would suggest that for any more extensive work that you get a cylinder of the correct gas as your corrosion resistance and strenght may be compromised by the incorrect gas.
On the subject of pickling paste - that is seriously nasty stuff, so remember your ppe - face visor and rubber gloves. By the way, you don't need to wire brush before pickling your welds and either a red or grey scotchbrite pad will blend your welds in nicely.
Keep playing around and good luck.

Originally Posted by Karl Robbers

I really don't want to sound negative, so I hope you take this in the spirit it is intended.

It's a critique after all! So negative and positive comments welcomed.

Why do you feel that if you were to run a bead it would take any more finishing than your series of tacks, (as it has been described)?

Did lots and lots of practice to get a bead that I felt looked good. I couldn't get a fine enough/neat bead. Not saying it's not possible but had to draw a line some where. Hardest bit about fine MIG welds is blending the start of the weld with the rest of the weld so the entire short length is even. No different to 20 odd years of MIG welding mild steel sheet metal for fabrication and automotive work.
My suggestion would be to have a bit of a play with some scrap ss and practice setting your voltage and wirespeed. Believe me you will be able to lay down the sweetest little corner to corner joint you have ever seen. I would suggest that for any more extensive work that you get a cylinder of the correct gas as your corrosion resistance and strenght may be compromised by the incorrect gas.
It's only the beginning of stainless work, so corrosion resistance and strength in this application is a non issue. Gotta start somewhere

On the subject of pickling paste - that is seriously nasty stuff, so remember your ppe - face visor and rubber gloves. By the way, you don't need to wire brush before pickling your welds and either a red or grey scotchbrite pad will blend your welds in nicely.
More than well aware of how dangerous pickling paste is. With the right gas I wouldn't need it but the Argoshield does leave a tough residue.

Keep playing around and good luck.

Lots more to learn and practice and the right gas is on the cards.

Bear in mind I had discussions with an experienced SS fabricator before deciding to do it this way. Sure he maybe wrong but the work I have seen in his factory looks excellent so I had some faith in his advice.

Cheers

Justin

Originally Posted by Jarh73

Lots more to learn and practice and the right gas is on the cards.

Bear in mind I had discussions with an experienced SS fabricator before deciding to do it this way. Sure he maybe wrong but the work I have seen in his factory looks excellent so I had some faith in his advice.

Cheers

Justin

Not saying that your stainless fabricator is wrong at all.
Where I was headed with my comment was along the lines of saying that a continuous bead would not be all that hard to achieve, particularly as you had a copper backing bar in place and would have actually been more aesthetically pleasing, (if you look carefully at the weld that you did it can be seen that each tack hasn't really blended properly and a visible crater can be seen in each tack weld).
When cutting/grinding/sanding stainless be careful to only use iron free wheels and do not use wheels on carbon steel and then stainless as iron can be transfered to the stainless that will cause staining.
It's all a learning curve.

Originally Posted by Karl Robbers

Not saying that your stainless fabricator is wrong at all.
Where I was headed with my comment was along the lines of saying that a continuous bead would not be all that hard to achieve, particularly as you had a copper backing bar in place and would have actually been more aesthetically pleasing, (if you look carefully at the weld that you did it can be seen that each tack hasn't really blended properly and a visible crater can be seen in each tack weld).
When cutting/grinding/sanding stainless be careful to only use iron free wheels and do not use wheels on carbon steel and then stainless as iron can be transfered to the stainless that will cause staining.
It's all a learning curve.

It's all good and taken on board. Absolutely no offense taken.

All grinding, cutting and sanding equipment is marked for SS only. And all iron free too.

When I get the right gas mix for stainless I'll certainly be giving thin material another go. Doesn't seem to "wet" as well on the thin material. I did some excellent practice right angle welds on some 1.6 mm that required no further treatment. However that was at higher current and the weld wet in very nicely. Welds had no starting lump and finishing slump.

Might do away with the oxyset bottles and get some stainless gas.

Cheers

Justin

is the copper for removing heat from the work so you don't make holes?
aaron

Originally Posted by azzrock

is the copper for removing heat from the work so you don't make holes?
aaron

That is partly the reason. The copper block also has the effect of supporting the joint and preventing over penetration with the resultant poor appearance plus the copper stops the atmosphere from contacting the penetration bead to some extent leaving a much cleaner weld from behind. Aluminium will also work but copper is best.
This technique is also of benefit where fit up is less than perfect.
If welding Aluminium a stainless steel block could be used.

I like it, Justin. I'd be happy with it.