New to TIG/Alum questions

[tom86951]

I've been practicing on 1/8" aluminum with my Miller Diversion 165. Despite everything I've heard, I have to say my aluminum beads after 2 weeks of practice are a heck of a lot cleaner than anything I ever got with MIG. A couple of questions:

1. Is my practice set up ok -- 3/32 ceriated, argon, 1/8" 4043 filler, on 1/8" aluminum?

2. Sometimes I'll get carbon marks around the weld. If everything was clean to start, does that mean I nipped the tungsten into the puddle and should regrind it?

3. Based on how fast/slow I go, and how much amps I give it, I can change the height, width, and ripple definition (i.e., clear ridges between beads, or smooth melted-together ridges). Are there any rules of thumb about how high, wide, and sharp the beads should be?

4. Anyone have a picture of an ideal bead run on a 1/8" piece of aluminum?

5. Sometimes the beads look fairly shiny and reflective, and other times they look more like cold solder joints with a more porous texture. What causes that?

6. I've watched lots of youtube video's, but they all tend to cover the same basics. Are there any good (more comprehensive) books or instructional series available?

[DSW]

3/32" ceriated is borderline at the amps you should be running to do 1/8" alum. It will work, but the tip usually won't hold up as well compared to running say 1/8" ceriated instead.


There's a good chance your marks are for dipping the tungsten. If you dip you should stop and regrind.

As far as that dull grainy look, sounds like you were running with the amps too low and too slow and overheated the material. Alum is fairly heat sensitive. Lots of new guys don't understand this and think they are doing well, when in reality their settings are totally wrong. You need to weld hot and fast with alum. It sounds counter intuitive, but more amps and faster travel speed actually reduces total heat input.


To do 1/8" with that machine you should have that machine maxed out as far as amperage goes. Hit it full blast to get the puddle going fast and then back off as the material heats up and move fast to outrun the heating material. With the stock 17 series torch, you won't get a lot of welding done before that torch starts to overheat running 1/8" alum.


Best suggestion is to post up picts of your welds with all the info. Then we can see what you are doing and make specific recommendations. Otherwise we are blindly guessing.

[shovelon]

^^^^^ What he said.

Only thing I would add is drop your filler wire size to 3/32 diameter and try 5356 as is holds it's shape better when overheating. It does not get mottled like 4043.

Don't know what your tungsten grind looks like, but I like to start out with a taper.

[tom86951]

Thanks guys. No laughing, here are some pictures of practice on 1/8" aluminum -- those are two 1" strips butt welded together. (And a what-the-heck try at welding an adapter plate on an old throttle body).

-- I grind the tungsten on a dedicated grinder wheel -- sharpening it to a point and then flattening the tip a bit.

-- As for turning the amps all the way up, I think I'd have to fly across the metal to avoid melt down, unless I let up on the pedal a lot...?

[shovelon]

Aha!

Turn your amps all the way up, Flatten the pedal to heat up the puddle and widen it, and then cram your rod in to freeze that bead. Move forward and repeat until all the way across.

Practice the movement before you strike your arc. Then pound the pedal and move it across. I am seeing some hesitation in your movements. Pump the pedal if you sense you are too hot. That why you have it, so make use of it.

But overall the weld looks clean and sound. Keep practicing. It will come to you.

Oh yeah, 1 amp per thousand of an inch is a rough estimate and for tranny tigs in particular. With inverter you have a much more stable and focused arc, so take advantage of it and haul ash.

[tom86951]

Should I be using a thicker rod then? As it is I have a hard time feeding the rod through my hand fast enough as it is. Is there some trick to that?

[DSW]

Trick? Practice... And lots of it. I tell students to take a piece of filler home with them and sit in from of the TV and practice feeding filler. You need to get the motions down to the point where it's second nature.

As far as larger filler, when your filler equals or exceeds the base material, things get a lot harder. 3/32" is what we have students use on 1/8" alum.

I know Terry likes to start out people on alum. I personally prefer they get the heat control down on steel 1st. Just a different method of teaching. In the end it all boils down to the same thing and that's heat control. Your pedal is the most important part, though filler can also play a significant role.


Keep practicing. I've seen a lot worse from new alum tig student.

[tom86951]

So I tried cranking up the amps and found it running way too hot -- creating molten sink holes if you will. I assume the idea is to turn it up just to get the puddle going, and then regulate with the pedal based on bead width? Also move to 1/8" filler, which on the margin allowed for faster filler (and, I now see, helps control heat a tad?). Which of these 3 beads (or portion thereof) is best, if any...

[yoshimitsuspeed]

The pedal is just like a gas pedal. You don't drive with your foot on the floor. You want your car to have more power than you need driving down the road. You want to be able to take off from a stop light or pull up a hill and you want more power available. While you are cruising down the road or running in the middle of a bead you will be mid throttle and modulating it to keep your speed/heat where you want it.

[shovelon]

So I tried cranking up the amps and found it running way too hot -- creating molten sink holes if you will. I assume the idea is to turn it up just to get the puddle going, and then regulate with the pedal based on bead width? Also move to 1/8" filler, which on the margin allowed for faster filler (and, I now see, helps control heat a tad?). Which of these 3 beads (or portion thereof) is best, if any...

I told ya, crank up the amps, floor it to add the heat, and cram the rod in to soak up that heat, and move fast. Alum conducts heat fast, and you want to keep pace or outrun that heat transfer. The more consistant you can add that rod, the better the weld will look. I see your bead overheating by forming silicon islands that mottle the finish. That is from using 4043. If you use 5356 you wont have that problem.

Anyway 165 amps is not that much. I do the same work at 200 amps or higher and make the pedal squeal like a pig, literaly. I sync the pedal pump every time I add the rod. If you really start overheating, back off the pedal.

And I personally would start with 3/32 diameter filler and just really cram and plump each bead. For comfort only would I jump up to 1/8th.

For the record, the bead at the left looks best to me.

[Drf255]

I told ya, crank up the amps, floor it to add the heat, and cram the rod in to soak up that heat, and move fast. Alum conducts heat fast, and you want to keep pace or outrun that heat transfer. The more consistant you can add that rod, the better the weld will look. I see your bead overheating by forming silicon islands that mottle the finish. That is from using 4043. If you use 5356 you wont have that problem.

Anyway 165 amps is not that much. I do the same work at 200 amps or higher and make the pedal squeal like a pig, literaly. I sync the pedal pump every time I add the rod. If you really start overheating, back off the pedal.

And I personally would start with 3/32 diameter filler and just really cram and plump each bead. For comfort only would I jump up to 1/8th.

For the record, the bead at the left looks best to me.

Sorry for the hijack.

So Terry, you pump the pedal with every dip? I remember B_C saying he did the same. I've tried it and I've gotten better dime stack definition and a flatter bead.

[tom86951]

Better?

[yoshimitsuspeed]

The top one isn't bad. I'd say you just need to keep laying down beads. Work on keeping your speed, rhythm and pattern consistent.

[DSW]

Top one is fair, but you are still overheating the material as noted by the grainy appearance of the weld.


Something that hasn't been clearly mentioned so far is the fact you need to let the material cool between welds, or dip it to remove the excess heat before starting your next weld. If you don't the excess heat will F with you. I tell students if they can handle the piece with their bare hands, it's cool enough to make the next weld. I also don't see any sign of material prep. Wire brushing the material with a dedicated SS brush will help remove the naturally occurring oxide layer. The oxide layer melts at a much higher temp than bare alum and can make your life a pain in some circumstances.


Starting with cold material, well brushed, more amps and travel faster and you'll end up with shinier welds with more definition.

[shovelon]

Sorry for the hijack.

So Terry, you pump the pedal with every dip? I remember B_C saying he did the same. I've tried it and I've gotten better dime stack definition and a flatter bead.

Yes I do 95% of the time.

[tom86951]

Top one is fair, but you are still overheating the material as noted by the grainy appearance of the weld.


Something that hasn't been clearly mentioned so far is the fact you need to let the material cool between welds, or dip it to remove the excess heat before starting your next weld. If you don't the excess heat will F with you. I tell students if they can handle the piece with their bare hands, it's cool enough to make the next weld. I also don't see any sign of material prep. Wire brushing the material with a dedicated SS brush will help remove the naturally occurring oxide layer. The oxide layer melts at a much higher temp than bare alum and can make your life a pain in some circumstances.


Starting with cold material, well brushed, more amps and travel faster and you'll end up with shinier welds with more definition.

Working on cool metal is one of those things that is obvious -- the minute after someone says it. I was zapping away over and over and the same pieces (lured in by that video that seems to show bead after bead on the same piece of aluminum). At any rate, tonight I focused on quality over quantity -- cleaned everything, reground, used the ss brush, and only worked on cool pieces. I promise to stop posting my welds everyday, but the feedback and tips have been very helpful. Here are three from tonight (ignore the melt-through from the other side), which seem shinier and less melted.... Better?

[DSW]

Don't worry about posting too many picts.


Top two look much better. You are too cold starting out, but as things heated up a bit they improved. I'd say you need to hit it harder at the start. I'm not seeing what I would expect of someone blasting it with the full 165 amps in those picts. You've still got a long ways to go, but there is definite improvement shown.


The heavy "lumps" shown in those picts are welds coming thru from the back side. Those tell me you were going way too slow and probably using too few amps on those welds and way overheating the material. Basically the only thing keeping those welds from dropping out was the fact the surface oxide layer melts at a hotter temp than the interior bare alum does. You had the interior all molten and completely out of control. That's why heat control and going fast to outrun heat buildup is so important. Good welds allow you to control the puddle. Eventually you'll get to the point where you can have a slight "bead" showing on the back side that's as even and consistent as the one on the front. Don't worry about that at this point. Concentrate on getting the top to look right 1st, then we'll work on full penetration when you eventually get to but joints, but that's still a long ways away.

[tom86951]

Two of the better looking ones from tonight for review and comment....

[shovelon]

Two of the better looking ones from tonight for review and comment....

Yeah, that's it now move onto joints. You wil find it hard to bridge the two pieces when they do not want to fuse, but poke the rod in and they will. Then move forward.