bit of trouble...

[jef88]

okay, been arc welding about a week (5hours a night or so laying straight beads after work), and my flat beads are now really great, welding 3/32" steel with 1/8" 6013 rods at about 80-90 amps (I think) and they're just right, look great and the reverse side of the sheet it still flat but the exact same colour as the weld, so I'm assuming that the penetration is about right..

So last night I decided to chop a bit of the end and weld it onto the sheet, assuming it would be easy enough like with mig. ha!

surprised i didn't give myself flash trying to tack it up, then I was either blowing holes through it or if I moved slightly faster it just made a crap weld, could break it with my hand, and then there was just 2 lines of beads each side of where I had welded this bit on.

I didn't turn the amperage down as I wasn't getting any spatter at all on my flat beads with this set up, but I may well be wrong...


All suggestions welcome, and I'll try and get some pictures up when my mam returns with the camera.

Thanks alot.

James

 

[rodofgod]

Hi James!

I think the problem your having could be due to magnetism! Welding beads of weld on a piece of sheet steel and then cutting and trying to weld together again is a recipe for this type of problem. Are you using AC or DC set?

Also, your rod size (3.2mm), while ok for just welding beads on plate (2.5mm), when it comes to welding a 'butt' type joint, I'd use a 2.5mm rod for the plate thickness you are using, at least to start with.

Regards

 

[jef88]

it's AC mate. magnetism does sound about right as even when i make it have it, the weld seems to disapear somewhere. i thaught you only got magnetism on DC > 250a though :s

 

[rodofgod]

James, magnetism is quite rare when using AC, but not UN-heard of, especially if the parent plate has had a lot of previous welding on it! From your description,I'd still go with the magnetism. Try and get a couple of 'Virgin' pieces of plate and see if you still have the same problem! Also try and post some pics of actual weld!

Magnetism can occur at any amps and is probably less likely the higher the Amps you are using!


Regards

 

[jef88]

Thanks for the reply rodofgod.

just been down my mates place (big plant works) and had a blast down there, went pretty well and and one point I had a really really great few inches of weld. I think you might be right, I also think the gaps between my 2 pieces at home were too much (between 1/32" and 3/64" i'd say).

anywho, the weld was _real_ messy, even messier than my first mma flat beads. but practice makes perfect, and the weekend is nigh!

Thanks alot for the help.

 

[aero]

Some pictures would pin it down

 

[Drains]

I get to disagree with Rod of God! Wahey!

It's not magnetism, it's the beginners bad technique. Jef, you're travelling too fast so the molten weld material never gets a chance to join up between either side of the butt. You need to start the arc, watch for the join.. hard to describe, but it looks like a quarter round, sort of meniscus affair. With a 6013, lengthening the arc a mil or so can help get you going, then go tight and get moving at the correct speed. It all happens very quick though - we're talking fractions of a second. Try upping your amps a bit too.

What happens with the bad weld is that the slag beats the weld to the joint. You need to get the molten metal in first, then the slag will ride on top. Practice practice. The too-wide joint certainly won't have helped, and RoG's suggestion of using 2.5s has got to be a winner!

RoG, the reason you (almost certainly) got it wrong is it's so long since you saw/did this, you've forgotten all about it

 

[rodofgod]

Hi All!
Drains, your explanation is spot on mate, and don’t worry, you’re not the first person who has disagreed with me and it’s not the first time I’ve been totally wrong either! Lol!
Your comment about how long I saw or did this is also very valid, it has been over 20+ years since I was in the same boat as many contributors on here and I will have to recognise this in future posts!
However, my reasons for stating magnetism over poor technique for jef88’s problems were that:
• He had stated that he had managed to deposit acceptable weld beads on a clean piece of plate with the given electrodes and power setting. This would assume a certain level of visual inspection of what was and was not acceptable! And competence!
• The fact that he had cut a piece of welded plate up and presumably placed it at right angles to the previously welded parent plate.
• The fact that ‘spatter’ played a part in the problem! Excess spatter is indicative of many problems, but in this case, magnetism would be no 1.
Your point about bad technique are more than likely more valid than mine. The fact that photo’s are possible on this site are are a god send in these cases!

Regards