[tigandmig]

I am looking for advice with some difficulty I have when welding .25" thick aluminum diamond plate. The material was sheared. The welds are outside corner welds. The machine being used is a Dynasty 350. Obviously set to A/C, machine defaults for wave type, orange, 3/32" Tungsten, 140 amps. 4043 filler rod. Argon gas. The material tacked together fine. The problem starts about .5" into the weld. The farther I travel, the dirtier it gets. Lots of black carbon type deposits. I have to stop and grind the last portion of the weld and then restart. It's like the puddle is getting more and more dirty as I go??? I have ground out portions of the weld, and the problem returns. Tried brushing edge with stainless steel brush. No change. 80 grit sanding sponge on the edge, No change. Acetone... no change. I'm no expert, but have welded aluminum before. Am I missing something??? Is there any specific settings I can use with this material? Thanks for any/all help!!!

[angus]

you could try a carbide burr.

when something is shear cut there are two things that can happen. if the shear is not a dedicated shear for aluminum, (somewhat unlikely) then you have the possibility that the blade has been contaminated with oil. the reason being the oil present on the surface of a lot of cold rolled sheet metal leaves a film on the bed and the cutting blade or if the hold downs on the shear are hydraulically actuated, over time they will occasionally leak small amounts of fluid onto the bed, onto the blade, then onto the edge of your material.

if your material was cut in an industrial job shop either of those explanations is probably why you are experiencing this issue.

a mill edge can also be an issue at times.

also, you should be running hotter and you could easily go to a 1/8th tungsten and 1/8th filler.

[gamble]

Your machine has lots of power and the ability to adjust electrode neg vs electrode pos independently from each other. So why not turn the amps up, turn the EP up or EN down. and that will give you a lot more cleaning. Not a cure all but it will help.

[rick9345]

Your machine has lots of power and the ability to adjust electrode neg vs electrode pos independently from each other. So why not turn the amps up, turn the EP up or EN down. and that will give you a lot more cleaning. Not a cure all but it will help.

Agree
Amps up More cleaning action(EP+)

[weldin mike 27]

Or, with aluminium, you can run a wood router around any edges to remove and crud. (cutting plates a little oversized obviously)

[Braehill]

Welding on an outside corner of Aluminum is one of the few times I like to use a small regular cup and not a gas lens, it seems to not send as much Argon down the sides. Not sure if that makes sense or not. You can also try a foil dam to keep the cover gas where you need it. Fit up is important too or you'll need a backer to keep the back side from pulling in atmosphere.

Just some things to try.

Len


Sent from my iPhone using Tapatalk

[tigandmig]

Thanks everyone! I'm gonna try these suggestions and report back.

[Bill Beauregard]

I too sometimes have a problem. After doing a thorough cleaning, by the system you like best, I clamp a copper 1-1/2" square inside. I have a couple pieces 8' and 20 " long, one corner is ground to a radius providing a nice profile on the back. My theory is the argon blowing through the gap can cause a swirling current mixing with air. The copper backer dams the argon providing back purge.Benefit two is clamping, benefit three is limiting the size of heat affected zone, benefit four is it eliminates burn through when getting good penetration.

[tigandmig]

Thanks everyone for your input. Ok... I made a couple changes. I set the amps to 175, the A/C balance 65% EN, and the frequency to 100. Things that were the same as before - Waveform: advanced squarewave, Gas: Argon, Tungsten: 3/32" 2% ceriated tungsten. I only did a slight more cleaning on the edge with a small stainless brush. Here's the result:

Good enough for the project, but I have one more small question/concern. when the AMPs are pushed to max value I set (175), the arc gets a little unstable and the tungsten starts to deform a bit. Is this due to the 65% balance? I've read on the Miller quick reference card that a 3/32" tungsten can go to 250A?

[TRACKRANGER]

Wow TigAndMig
It looks like you're on top of things now, for sure!

[gamble]

Yes, remember more cleaning is more heat into the tungsten. So you can run a 3/32 tungsten at 100amps but if you have a lot of cleaning the tungsten will go to crap quicker than say 150amps at a lot less cleaning.

[angus]

I don't understand about the 175 max amps.

I assumed with a dynasty 350 you would be operating with a cooler, water cooled torch, foot pedal or maybe a slider on the torch handle.

I can see that the material is polished, you said it was 1/4 in. thk, is it 3003 alloy? just curious because that alloy has
been known to present problems when welding. some use 1100 most use 4043.
I would suggest switching to a 1/8 th tungsten.

the weld looks good; was that welded with 3/32 rod? I only ask because a corner to corner weld on 1/4 inch thk material is going to require feeding a lot of rod and that looks to me like a single pass, plus the weld is somewhat smaller than what I would imagine it to be.

I suggested the carbide burr but the guy that mentioned the router had the better alternative if there was a lot of edge to clean. I have also used a plane to skim a straight edge. you have to make sure the blades are set for very light removal or else you'll toast them.

[motox]

angus
the plane idea is great.
do you have to grind the blade with
less angle?
craig

[angus]

angus
the plane idea is great.
do you have to grind the blade with
less angle?
craig

I have a Makita electric planer. I only use it as a last resort. I sold an identical one for parts on ebay not that long ago because my helper laid into a large weld that was left behind when a fender cleat was torn off the side of an aluminum boat. it tore up the blades and the part they are fixed to. I have used them on occasion to skim the mill edge on sheet stock. I don't know about a carpenter's plane so I can't advise on sharpening the blade but I would not hesitate to give it a try.

[tigandmig]

I don't understand about the 175 max amps.

I assumed with a dynasty 350 you would be operating with a cooler, water cooled torch, foot pedal or maybe a slider on the torch handle.

I can see that the material is polished, you said it was 1/4 in. thk, is it 3003 alloy? just curious because that alloy has
been known to present problems when welding. some use 1100 most use 4043.
I would suggest switching to a 1/8 th tungsten.

the weld looks good; was that welded with 3/32 rod? I only ask because a corner to corner weld on 1/4 inch thk material is going to require feeding a lot of rod and that looks to me like a single pass, plus the weld is somewhat smaller than what I would imagine it to be.

I suggested the carbide burr but the guy that mentioned the router had the better alternative if there was a lot of edge to clean. I have also used a plane to skim a straight edge. you have to make sure the blades are set for very light removal or else you'll toast them.

I actually started out lower than 175... Yes, water cooled torch and remote foot control. Before I got the material, I did a little research on Miller's site and used their TIG calculator to come up with a place to start. For 1/4" Aluminum, corner weld, I got --> 3/32" tungsten, A/C high freq, Amperage range 140-170, Argon gas at 25 cfh.

It is 3003, I believe.... very soft and gummy. I did use 4043 rod. I think I may try 1/8" tungsten on the second part. Or, I may try a little less cleaning action.

Thanks! Yes, 3/32" rod, single pass, and I was feeding it fast. I may try larger rod too... I think my cleaning of the edge with the sanding sponge and stainless brush was sufficient. Especially since it was sheared. I guess I just had the settings too far off... or maybe I was standing on the gas supply hose...

[Bill Beauregard]

I wonder if the 250 amp figure is for DC. You get considerable tip splitting, or nodules at high amperage on AC. Jody suggests intentional balling to prevent this.

[Boomer63]

I have been having similar problems with aluminum welding; very dirty results. In the end, I think it was the filler metal. I purchased new filler rod, and the problem dried up. I did clean the old rod, but that didn't help.

[GreinTime]

I have a whole box of Alcotec 5356 that I hate with a passion. It's junk as far as I'm concerned.

[Superiorwelding]

I have a whole box of Alcotec 5356 that I hate with a passion. It's junk as far as I'm concerned.

Sam,
Well, I can think of someone who might could use it. Hint, hint.
-Jonathan

[Braehill]

He knows where there's a shelf that was holding that box of filler rod up when he got it and it can go back there if he doesn't want it.

Len

[Otto Nobedder]

You can take that Alcotec and weld the crack the sun doesn't shine on...

[Superiorwelding]

You can take that Alcotec and weld the crack the sun doesn't shine on...

Wonder what polarity and amperage you would need for that?
Not "straight" for sure.
-Jonathan

[tigandmig]

I wonder if the 250 amp figure is for DC. You get considerable tip splitting, or nodules at high amperage on AC. Jody suggests intentional balling to prevent this.

Yes, and on the Aerowave I used to use we would intentionally ball the end. The Miller documentation for this Dynasty recommends using a sharpened tunsten with a slightly blunted tip...