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where is the penetration?

Posted: Wed Jun 21, 2017 2:05 pm
by crimas
Hi guys, today while i was welding 2mm aluminum t-joint i thought to cut it and put some welding cleaner gel (how says jody if you aren't certe of your weld cut it) and see if is a goood weld, so i found no great penetration, luckily it was a test before welding other pieces, whats is wrong? im using 100hz 35%balance 140Amp with foot pedal , 4043 filling rod, maybe more heat input required?

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Re: where is the penetration?

Posted: Wed Jun 21, 2017 2:24 pm
by Skylineauto
I would try it again with the same amps but increase your frequency to 150 and try and try to get a tighter arc length.

Re: where is the penetration?

Posted: Wed Jun 21, 2017 2:26 pm
by cj737
Which side of the T did you weld first? Smart money says the right (in the sectioned photo) where you base metal was not hot enough. By the time you weld one side, the base is now very hot, and the penetration much greater for the other side.

Having sufficient heat to melt the filler is not enough to insure fusion. You need to heat the base metal up until its "wet" and puddling then add filler to prevent burn through. So, in essence, yes, you need more heat. Or wait longer to add filler, or add less filler/smaller diameter. The filler "cools" the puddle each time so you need to recover the base metal heat as you go.

You probably noticed how much faster you welded the other side than the first. Again, its the accumulated heat soaking in and allowing you to use less heat overall.

Re: where is the penetration?

Posted: Wed Jun 21, 2017 2:30 pm
by ignatz200
Judging by your etching test I would say that you did not wait for the base metal to puddle, but merely succeeded in melting your filler metal onto the fillet instead of into it. The wide weld bead (laying on top of the base metal) also indicates that you are holding your torch too far away from that inside corner.

Re: where is the penetration?

Posted: Wed Jun 21, 2017 2:52 pm
by crimas
cj737 wrote:Which side of the T did you weld first? Smart money says the right (in the sectioned photo) where you base metal was not hot enough. By the time you weld one side, the base is now very hot, and the penetration much greater for the other side.

Having sufficient heat to melt the filler is not enough to insure fusion. You need to heat the base metal up until its "wet" and puddling then add filler to prevent burn through. So, in essence, yes, you need more heat. Or wait longer to add filler, or add less filler/smaller diameter. The filler "cools" the puddle each time so you need to recover the base metal heat as you go.

You probably noticed how much faster you welded the other side than the first. Again, its the accumulated heat soaking in and allowing you to use less heat overall.
it's strange because i weld first the left side of the joint, the small weld with the greater penetration, , then i weld the right side, with more filler, maybe too much fill cools the puddle too much...

Unfortunaly my machine have limited frequency settings, 100Hz max, can i try different wave form instead of increasing amp? im using square wave, but i have triangular, sinusoid and soft square to choose...

Re: where is the penetration?

Posted: Wed Jun 21, 2017 6:46 pm
by LtBadd
crimas wrote: it's strange because i weld first the left side of the joint, the small weld with the greater penetration, , then i weld the right side, with more filler, maybe too much fill cools the puddle too much...

Unfortunaly my machine have limited frequency settings, 100Hz max, can i try different wave form instead of increasing amp? im using square wave, but i have triangular, sinusoid and soft square to choose...
Remember if your arc length is even a little to high, or a bad torch angle you'll quickly lose penetration. You are okay using square or soft square wave, triangular is for thin material, sine wave mimics a transformer machine, I'd recommend not using it for this weld.

Re: where is the penetration?

Posted: Wed Jun 21, 2017 11:28 pm
by cj737
What machine do you have that has that many wave forms but only 100Hz for frequency options?

Re: where is the penetration?

Posted: Thu Jun 22, 2017 4:50 am
by crimas
cj737 wrote:What machine do you have that has that many wave forms but only 100Hz for frequency options?
i think is made is the same place where everlast is made because its very similar, have the same interface,function, maybe have limited frequency because is cheaper hahahaImage

Re: where is the penetration?

Posted: Thu Jun 22, 2017 6:17 am
by AndersK
I assume you can go lower than 100 Hz so try that. Looks like you have nice clean aluminium so try and reduce cleaning action as much as you can.

Both changes will increase penetration.

Also make sure the arc isn't focused on just one side of the joint, which it can do when lowering the frequency. You might have to wiggle the torch a little to get the arc on both sides.

Re: where is the penetration?

Posted: Thu Jun 22, 2017 2:07 pm
by crimas
trying with standard n°7 cup instead of gas lens, 30% balance ( the lower i can setting) more focused arch lenghts slow my traveling speed and wait for great melting before fill the rod, it seems im going to the right direction, more penetration, i tryed different filling rod; in the photo i used 4043 but in the piece welded with 5356 rod when i put the acid (stainless weld cleaner)i cant see the different beetween the two metal, its look like is a unique piece, what different tipe of acid i can try ?ImageImage