[jrogers80]

Hey guys I recently bought a dynasty 280dx, got it all set up and in playing with some aluminum it just won't weld. I cleaned the heck out of it with acetone and a ss brush but it won't fuse together. A practice bead looks fine but trying to do a fillet weld and one piece melts and the other wont. Both are cut from the same sheet of al so I know it's the same material. Any help would be nice. I will try to bet pictures.

[Aleksi86]

At quik try focus your arc eavenly on both sides, and maybe adjust HZ Frequence if you can? bigger the HZ like 150-200 the narrow the arc is.

[Aleksi86]

At quik try focus your arc eavenly on both sides, and maybe adjust HZ Frequence if you can? bigger the HZ like 150-200 the narrow the arc is (i mean that lower it if its big).

[jrogers80]

THanks I will try that and let you know how it turns out.

[dirtmidget33]

I have had this a couple of times when fit up wasn't great. One thing I found that helped was get a puddle on one side and wash it into other piece. Once the pieces joined welded fine. Sort of technique I used playing with soda cans too. Only there I puddled on filler and wash it into cans then it's off and running.

Does the arc only go to one side if you can't strike arc on one side then that side not getting a good ground. Had poor fit ups not give other side great grounds too.

[nickn372]

One small note.... I have had ground issues with aluminum bad enough that the arc would jump to my filler as I dipped it. Why the ground was stronger on my filler ended up being a cleaning issue cuz I tried running beads won another piece of aluminum and it ran fine but I went back to the square tube I was working g with and the issue came back. So I'd look at cleaning and ground. Don't be afraid to over amp it just a bit too to try to start a puddle. A quick stomp of the pedal can sometimes jar some crap loose that causes issues whatever they may be.

[TRACKRANGER]

What's the thickness of the material, and what amps are you using?

If you can't get aluminum to 'wet' almost instantly (1-3 seconds) when you light up on it, you run the risk of just increasing the oxide layer, and then you're at the point of no return. You've got to get through the oxide first. This might help, I hope.

Also, the arc will only flow between the electrode and wherever the ground path is. If one piece isn't grounded, no arc and therefore no heat goes there.

Cheers

Ranger

[RichardH]

I have had this a couple of times when fit up wasn't great. One thing I found that helped was get a puddle on one side and wash it into other piece. Once the pieces joined welded fine. Sort of technique I used playing with soda cans too. Only there I puddled on filler and wash it into cans then it's off and running.

Does the arc only go to one side if you can't strike arc on one side then that side not getting a good ground. Had poor fit ups not give other side great grounds too.

+1

If fitup isn't good, the heat won't transfer from the piece where you light up, and the other side of the joint won't wet. Or the gap is enough that the puddles won't bridge the gap. Adding a little filler to start fixes this for me, particularly if welding a deep joint like down the length of round stock laying on a flat piece - feeding filler to make the puddle bridge both pieces gets the heat distribution jump-started.

[Bill Beauregard]

Hit it hard! You need to be very aggressive to start your puddle, I focus the arc a bit away from the joint, lots of heat at first, switch once or twice to the other side of the joint. After a bit of pre heat, lots of peddle right on the center of the joint, the arc may insist on one side or the other, form a puddle, dip, wash the liquid to the other side. As soon as a bridge forms you are golden. Close arc, near perpendicular to the bead, stay on the leading edge of the puddle. With practice you learn to move fast. As a spot for a new dime wets, dip filler, move on. I like auto set, 200HZ. Use a chart for heat settings at first if you like, but it's hard to get too much unless your metal is thin. Your peddle controls avoiding too much heat. After a few tries you'll know to set it at the most heat you'll want to start. Preheat also helps.

[aeroplain]

I used to have this problem ALL the time. When I found out that stick out was to short and arc length tightened up, things went as they should.

[dirtmidget33]

I have had this a couple of times when fit up wasn't great. One thing I found that helped was get a puddle on one side and wash it into other piece. Once the pieces joined welded fine. Sort of technique I used playing with soda cans too. Only there I puddled on filler and wash it into cans then it's off and running.

Does the arc only go to one side if you can't strike arc on one side then that side not getting a good ground. Had poor fit ups not give other side great grounds too.

+1

If fitup isn't good, the heat won't transfer from the piece where you light up, and the other side of the joint won't wet. Or the gap is enough that the puddles won't bridge the gap. Adding a little filler to start fixes this for me, particularly if welding a deep joint like down the length of round stock laying on a flat piece - feeding filler to make the puddle bridge both pieces gets the heat distribution jump-started.

Didn't realize when I typed my response up on break about washing the puddle forgot to mention I add filler when washing over. glad you pointed that out for him. doesn't wash to well without it.

['Stang]

Hey guys I recently bought a dynasty 280dx, got it all set up and in playing with some aluminum it just won't weld. I cleaned the heck out of it with acetone and a ss brush but it won't fuse together. A practice bead looks fine but trying to do a fillet weld and one piece melts and the other wont. Both are cut from the same sheet of al so I know it's the same material. Any help would be nice. I will try to bet pictures.

Your problem is your torch angle. When you do a fillet weld on aluminum, you always need to concentrate your heat on the thickest piece. The material may be the same thickness-but the lower piece is wider. It has more room for the heat to go. The base piece can absorb the heat . The vertical piece can't absorb the heat. The edge will burn off. Concentrate your torch on the lower piece-then wick over to the vertical piece. Add filler!

[rick9345]

On alum a good ground is just as important as a clean joint
I use small jumpers to each part
I use a set of cheap 8 ga auto jumper cables to supplement my table
Oxide on alum prevents a good ground just like it can prevent a good arc start
Black spots on backside of alum laying on grounded table is oxide burn through seeking a ground path
don't under estimate the power of ground needed for any material, it can have large influence on weld appearance/quality

When trying solve bad/poor arc starts look for improper /bad grounding

[Bill Beauregard]

Aluminum's ability to conduct away heat is astounding! If you're on it too long it has time to conduct the heat away, meanwhile the gas coverage is never truly complete, it skins with contaminants. your bridge has to be built quickly or not at all. Once you join the puddles on both sides of the joint, heat conducts pretty well and keeps the puddle at the joint. Hot, liquid aluminum receives the arc, and reestablishes well for the second half cycle. Set your balance as high as you can for effective etching, seldom will you need it to be in the 60% range.

[TwentyFourSeven]

You have to move the tip of the torch so the arc is hitting each piece evenly. Also I have noticed keeping the tip of the electrode 1/8" away from the metal makes a big difference.

[TRACKRANGER]

You have to move the tip of the torch so the arc is hitting each piece evenly...

It'll never be able to hit each piece evenly if both parts are not evenly connected to the return path. This is likely to be related to the O/P's problem

[rick9345]

You have to move the tip of the torch so the arc is hitting each piece evenly...

It'll never be able to hit each piece evenly if both parts are not evenly connected to the return path. This is likely to be related to the O/P's problem

thought I already stated that
On alum a good ground is just as important as a clean joint
I use small jumpers to each part
I use a set of cheap 8 ga auto jumper cables to supplement my table
Oxide on alum prevents a good ground just like it can prevent a good arc start
Black spots on backside of alum laying on grounded table is oxide burn through seeking a ground path
don't under estimate the power of ground needed for any material, it can have large influence on weld appearance/quality

When trying solve bad/poor arc starts look for improper /bad grounding

[Blaze659]

Is the aluminum alloy your using weldable? Not all are.

[Bill Beauregard]

Update us. How are you doing?

[TRACKRANGER]

Is the aluminum alloy your using weldable? Not all are.

That's a great point. We had a job come in once to attach some flanges to a machined tube. We'd done them previously without issues. All parts supplied were supposed to be 5052 alloy. After dismal (no) success we went back to supplier and asked them to check.

Answer: Oh, they were out of 5052, so used 2011 instead. Would that matter? they asked.

[jrogers80]

Hey gys thanks for all of the advice but I haven't been back to the welding table yet..but I will get more seat time soon.. nothing like having a new 280dx and not using it