[Blaze659]

I'm trying to make an aluminum beach cart for my brothers birthday. I can't get the metal for the cart to puddle, the metal just ends up warping. But if I light up on different aluminum I get a nice puddle and bead for my experience level. Do you all think I got some unweldable aluminum delivered instead of weldable aluminum? All the metal was cleaned the same. What does unweldable aluminum look like when you light up on it? Thank you for your time!

[Oscar]

When you light up on the "different" aluminum, is it the same exact sized part, thickness, and joint configuration?

[exnailpounder]

All metal will puddle and weld but alloys that are"unweldable" will crack and brittle out and all kinds of good stuff so thats why they are termed unweldable. You may have a piece of anodized or contaminated or something giving you fits.

[RamboBaby]

Looks like a thin to thick situation to me. Same scenario when you try to weld up to an edge. You need to keep your heat concentrated away from that edge, add a good glob of filler and then quickly sweep your torch angle back toward that thin edge (while keeping your filler wire positioned just over the top of the puddle and next to the thin edge). This will tie the two pieces together and it will instantly add anoher drop to the puddle because of where you had your filer wire placed. As soon as you see the pieces tie together then you need to instantly sweep the torch angle back toward the center of the puddle and stab another glob of wire into the joint. Now you can begin to move forward toward the leading edge of the puddle. DO NOT move your torch beyond the leading edge else you're gonna blow back that thin edge just like you did in the photo that you posted. If your puddle isn't penetrating into the root of the joint (lack of fusion) then you just need to sweep the torch angle (not the torch position) slightly forward so that it points at the leading edge of the puddle. The arc force will drive the molten puddle deeper into the root of the joint. Sometimes you may have to do this a couple of times before you get deep penetration into the root. The reason you may have to do it more than once is this: keeping the torch pointed toward the root at the leading edge for more than a split second is often enough to blow that thin edge away. It just takes practice. It's a whole lot to watch (leading edge, root, sides and height while at the same time modulating heat input and trying to keep even ripple spacing AND adding the appropriate ammount of filler to maintain even throat depth).
I personally went to a hypnotist knowing all of the things that I should be doing while being too overwhelmed to focus on it all at the same time. Didn't feel like I had gotten my money's worth until two days later when I saw everything starting to tighten up and, within a week, my welds were about three times better than they had been before I had that lady hypnotize me.
Just keep watching the puddle and trying to focus on everything that you know you should be. That puddle really will tell you everything that you need to know......you just have to be focused enough to read it.

Edit: clamping your metal down tightly will keep it from warping. I've never been in a situation though where I've seen aluminum warp. That doesn't mean that it can't happen though.

[Blaze659]

I cut 2 exact size pieces of another stick of aluminum and they welded clean. The only difference between the metal is the one having the issue was ground shiny months ago and sat in my shop but was reground today. If the aluminum got contaminated how do you get clean besides grinding it? Just doesn't make sense. Also, when the puddle won't start and you try to add rod the rod just balls up on its self.

[Oscar]

If you're grinding on it, you may be doing to much and smearing the oxide layer deep into the metal. Acetone wipe - SS wire brush - Acetone - SS wire brush - Acetone is what I do. No "grinding" of any kind on aluminum for me.

Your first picture shows a butt/edge weld, where as your second picture shows an inside fillet weld, which is why I was asking about the various pieces you had practiced on. Have you successfully ran a bead on an inside corner joint of the same size part and thickness using aluminum? If no, then you simply need more amperage and initiate with a tighter arc length. If yes, then simply go back to those settings you used for the successful weld bead.

[RamboBaby]

A stainless wire brush dedicated to aluminum. I regularly grind aluminum with the same flap disk that I use for everything else. It is usually obvious when the flap disk contaminates the puddle because it behaves poorly and looks like crap. You can usually tell when it's contaminated because you can either see crap floating to the top or it acts more sluggish than usual (not sure that that second scenario adequately describes how it really acts....it just doesn't do what you know that it's supposed to be doing). Not bearing down with the flap disk seems to help prevent this somewhat.

Alternatively you can use a cleaner like alumabrite:

http://www.envirotechcoating.com/produc ... m-cleaner/

Alumabrite ingredients list:

http://www.google.com/url?q=https://www ... 5HHI0bOwzQ

[Kevin_Holbrook]

looks like your having problems with the fillet welds in aluminum , I'm assuming 1/8 material thickness

thing that have worked for me :



number 5 cup 3/32 tungsten with 12 CFH , too much gas will steal heat from the puddle and if your at too much of an angle it will suck air into the weld

tungsten ground to a point , 1/4 stick out , hold a really tight arc , if you don't start out with a tight puddle that has penetration it's very hard to get it through the rest of the weld bead

1/6 to 3/32 filler wire , too heavy of a filler wire and it will steal heat from the puddle

make sure both pieces ( sides of the weld area ) are grounded , if not grounded correctly the arc might jump to one side

[RamboBaby]

Too tight of an arc and you will discover that instead of sticking your electrode into the puddle, the the puddle will jump into your electrode. It's like watching a magnet sweep up iron filings. That's why you'll see Jody lift his torch when dabbing filler wire, and move it ahead as he lowers it back down with aluminum. When it happens (and it's going to happen to you a lot) you are going to know it instantly because you'll hear it explode and it instantly throws black soot everywhere.

[Kevin_Holbrook]

Too tight of an arc and you will discover that instead of sticking your electrode into the puddle, the the puddle will jump into your electrode. It's like watching a magnet sweep up iron filings. That's why you'll see Jody lift his torch when dabbing filler wire, and move it ahead as he lowers it back down with aluminum. When it happens (and it's going to happen to you a lot) you are going to know it instantly because you'll hear it explode and it instantly throws black soot everywhere.

it looks to me like he's having trouble starting a puddle in a fillet weld , from his top pic it looks like he was able to run a bead

[Oscar]

Also, when the puddle won't start and you try to add rod the rod just balls up on its self.

You're not supposed to add filler rod before the aluminum turns shiny like a mirror, hence why you're seeing what you're seeing. Lets go back to basics. What thickness aluminum are you working with, and how much amperage are you using? What is your actual arc length? What is your torch angle, roughly?

[Artie F. Emm]

Also, what are your AC balance and frequency settings?

[Blaze659]

Oscar,
I'm welding 1/8 wall tubing. I've tried 130, 160 and 200 amps but can't get the shiny puddle to start in the inside corner joint. Even at 200 amps the metal just heats up and melts without ever creating a shiny puddle or any puddle. I usually point the tungsten right at the crease where the two pieces touch. But even pointing at one does no good. I've tried welding the inside corner with it horizontal and vertical. I can hold and hold the Arc in one place and no puddle will Form then the metal warps and melts through. I can't blame the machine it welds nice beads otherwise. I am also having trouble with it starting a puddle on some aluminum my brother in law had sitting outside for awhile even after grinding it shiny. I have dedicated aluminum flap disks. Dedicated stainless brush. Acetone. I have grounded my table and also hooked the grounding cable straight to the work piece. I'm so fustrated I quit working on the project because it doesn't make sense. Maybe the machine is messing up but I don't see how one minute it runs a bead than the inside corner won't work. The piece for my brother in law is a piece of round tubing being welded to another to make a roll box fishing pile holder. Those pieces connect like an inside corner and the bead won't start there either. Thank you for your time!

[Blaze659]

Oscar, I'll also see if I can attach a video.

[RamboBaby]

That sounds like you forgot to set you your machine to alternating current. You will never get a shiny puddle without ac (unless you're running pure helium) and the base metal will just cave in. If you have your ac balance way too low the same could happen. Castings often weld in a similar manner. I've never personally welded one but seen the boss do a lot of them and they often just look like dull, bubbling crapola.

[Oscar]

Yea, sounds almost like it might be set or stuck on DC. Until we see pics, it's all just guessing.

[weldit321@gmail.com]

I use a $15 harbor freight air grinder with a Roloc attachment, and 3m Scotchbrite roloc pads (maroon) to clean my aluminum. Simply run it over with that and blow it off. Ironically I believe the abrasive in these pads is aluminum oxide, but all the impurities seem to blow away and I rarely have problems doing this. If it is super critical however I will use acetone after this.

[Blaze659]

The bottom pic on the very first post is what happens when you light up on it. The Arc is noisey, different then frequency noise and as you hold it in place waiting for a shiny puddle to form, Bam, the metal warps through. I think oscar is right my machine is having a problem switching to ac. The DC current works but the ac is sporadic causing it not to weld right.

[RamboBaby]

Try holding a DC arc to the unweldable piece and see what happens. It looks like brushed stainless steel to me.