Looking for some AL welding critque

[600SL]

The first paragraph of this is bad advice. You want a gas lens vs a collet body due to the more laminar flow of gas. This allows you to put the electrode out where you can see it, and makes for a better shielding envelope for a given gas flow.

As for recessing the electrode into the cup, this is also not a good idea. The arc is bell shaped. The closer you get your tungsten to the work, the more intense and focused the heat is. When you have an increased arc length, it increases the overall amperage needed, and due to the wider arc also makes it harder to control heat input. The only time I pull the electrode into the cup is when I will be walking the cup on pipe, and the roundness of the pipe allows me to see what I'm doing while the cup is resting on the metal.


Finally, if your filler is melting before you get it into the puddle, your torch angle is wrong. Probably due to the tungsten being so far into the cup you tilt the torch more to see it.

The second paragraph is right though, a few seconds of cleaning action before you give it the beans can help, as well as let you get the arc stabilized and get your bearings.

I came to the conclusion that the gas lens worked better. As far as stick out I usually stick the tungsten out the diameter of the cup. #6 cup stick out is 3/8". I could probably get away with less stick out for everything but the inside corner fillet welds.

On the inside corner fillet welds my filler is melting before I get to the puddle. I believe I'm holding the torch angle at the perfect text book 15° off the vertical but the puddle seam to lag behind the torch and I have to dip under the torch to get at it. While dipping under the torch the filler melts before reaching the puddle. Jody from Welding tips and Tricks shows a method of backing off the torch for each dip. Seams like it would work good for this situation but I will need to develop better better filler rod feeding control before I can apply it.

 

[600SL]

I did a little better today but I'm not sure if I was using unorthodox welding practices to get there.

The two areas I was having trouble with were the inside and outside corners.

For the outside corners I pulsed the pedal as I had reported earlier and using no filler got it to weld together nicely with a small easy to fill hole here and there. That gave me really nice looking weld but thin so I took another pass over it with filler to build it up and they looked reasonable good.

For the inside corners. They took a lot of current. Had the machine set to 120 amps. Went peddle to the medal to start the puddle. I had to get the filler to melt first to transfer heat to the base material to get the puddle formed. Trying to form a puddle first usually ends up with a hole. With the puddle started I fed the rod continuously into the puddle as I moved forward. No dipping and I used a 1/8" rod for this pass. I used the 1/8 rod because the 1/16 rods were consuming too fast to keep under control. This produced a heavy but consistent weld. I may elect to try this with a little more stick out and the smaller rod.

Unfortunately for some reason my side welds were off today but at least those are easy to fix.

So for today I had the machine set to 120 amps. #6 cup, 15 CFH. Today I also tried out an E3 1/16" tungsten. These work real well. Much better than pure tungsten, not sure if they are better than the Zirconium. But they are almost 2 times the price of all the others so I believe the E3 will be short lived. For all the welding I used 1/16" 4043 filler rod except for the inside corners I went to 1/8" 4043. The material was 2" x 1" 0.062 rectangular tube.

 

[buildyourown]

The first paragraph of this is bad advice. You want a gas lens vs a collet body due to the more laminar flow of gas. This allows you to put the electrode out where you can see it, and makes for a better shielding envelope for a given gas flow.

As for recessing the electrode into the cup, this is also not a good idea. The arc is bell shaped. The closer you get your tungsten to the work, the more intense and focused the heat is. When you have an increased arc length, it increases the overall amperage needed, and due to the wider arc also makes it harder to control heat input. The only time I pull the electrode into the cup is when I will be walking the cup on pipe, and the roundness of the pipe allows me to see what I'm doing while the cup is resting on the metal.



.

I know this is slightly unconventional. I assure you, I do plenty of this for a living and my results are better with a regular collet body. I got the idea from watching other welders and it works for me. I dont have a problem welding when I cant see the electrode, so stuffing it in the cup works and I can still keep the torch angle right. I can tell where things are by watching the puddle.

I dont have any pics of my own work to back it up, but here is another guy who does mostly woodwork who I got the idea from.
https://www.instagram.com/crummywelding/

 

[Jim Johnstone]

Do any of you guys pre heat the parts before welding aluminum? There is a fab shop in the same building as our machine shop and the welder there was welding some aluminum structures for us and he was hitting each joint with a big propane rosebud torch before welding each joint so he doesn't get a cold start from the aluminum sucking the heat away from the weld.

 

[sberry]

You can, especially on thick work with under powered machines.

 

[Superbec]

I dont have any pics of my own work to back it up, but here is another guy who does mostly woodwork who I got the idea from.
https://www.instagram.com/crummywelding/

maybe try finding some real pics of your work before posting here ... not some other woodworker.

close the windows before you take the pictures so the birds don't fly in and you have no excuse

(that was a welder joke )

 

[600SL]

I know this is slightly unconventional. I assure you, I do plenty of this for a living and my results are better with a regular collet body. I got the idea from watching other welders and it works for me. I dont have a problem welding when I cant see the electrode, so stuffing it in the cup works and I can still keep the torch angle right. I can tell where things are by watching the puddle.

I dont have any pics of my own work to back it up, but here is another guy who does mostly woodwork who I got the idea from.
https://www.instagram.com/crummywelding/

I actually tried this based on your previous recommendation. I have actually done this quite a bit with steel when I have trouble getting at it. In this case there was no appreciable difference.

 

[dr_clyde]

I know this is slightly unconventional. I assure you, I do plenty of this for a living and my results are better with a regular collet body. I got the idea from watching other welders and it works for me. I dont have a problem welding when I cant see the electrode, so stuffing it in the cup works and I can still keep the torch angle right. I can tell where things are by watching the puddle.

I dont have any pics of my own work to back it up, but here is another guy who does mostly woodwork who I got the idea from.
https://www.instagram.com/crummywelding/

I never said you couldn't weld alum with a regular collet body. It works fine for most things. However, I started using gas lenses a few years ago out of curiosity and haven't looked back. For me, I much prefer the benefits that the gas lens provides. There aren't any disadvantages as far as I'm concerned. It really comes down to personal preference.

 

[dffay]

2% Lanthanated for everything. Really. I think tungsten and helium (heliarc) got along better and I suspect it was a carryover with Argon.

HF sells a $9.00 three piece diamond surface grinding wheels. They are about an inch and a quarter in diameter. I chucked one wth the shaft provided in the kit to a mounted electric motor that has a three jaw drill chuck on the shaft. It grinds the point beautifully and I haven't worn the first one out yet. I can't imagine the synthetic diamond dust surface causing any contamination.

 

[MoonRise]

For the outside corners I pulsed the pedal as I had reported earlier and using no filler got it to weld together nicely with a small easy to fill hole here and there. That gave me really nice looking weld but thin so I took another pass over it with filler to build it up and they looked reasonable good.

Do NOT weld 6xxx without using filler. It WILL crack.

Right from Lincoln's Aluminum GMAW guide (but most of the info applies no matter what actual welding process is being used):

Silicon And Magnesium (6XXX series). This medium strength, heat-treatable series is primarily used in automotive, pipe, railings and structural extrusion applications.
The 6XXX series is prone to hot cracking, but this problem can be overcome by the correct choice of joint and filler metal. Can be welded with either 5XXX or 4XXX series without cracking — adequate dilution of the base alloys with selected filler wire is essential. A 4043 filler wire is the most common for use with this series.
6XXX alloys should never be welded autogenously, as they will crack.

(emphasis added by me)

When you welded the outside corners without filler and then went back and added filler, if you didn't completely melt your first pass weld bead and dilute the puddle with the added 4043 filler rod, there is a pretty good chance that you will have a crack underneath in the first pass weld bead.

Just the metallurgical nature of the 6xxx aluminum alloys.

Another Lincoln quote, from a few pages farther along in the same document:

6XXX Alloys— These Al-Mg-Si alloys are primarily used for extrusion alloys,
although they can often be found as sheet and plate as well. The chemistry of these alloys makes them very sensitive to hot short cracking. Autogenous welds (i.e., welds made without adding filler metal) will almost always crack. This is why 6061 filler metal does not exist. If it did, welds made using it would crack. Yet these alloys are readily weldable using either 4043 or 5356 filler metal. Since the chemistry of 4043, Al with 5% Si, or 5356, Al with 5% Mg, is so different from that of 6061, when either is mixed with 6061 the result is a weld with a crack resistant chemistry. In fact, the vast majority of weld cracking in 6XXX alloys is caused by not adding enough crack resistant filler to the weld, leaving it crack sensitive. Weldments that use square **** joint preparations are particularly prone to this problem. The easiest
solution is to make a small V preparation instead of a square ****, which allows the welder to add more filler alloy.

 

[600SL]

Do NOT weld 6xxx without using filler. It WILL crack.

Right from Lincoln's Aluminum GMAW guide (but most of the info applies no matter what actual welding process is being used):



(emphasis added by me)

When you welded the outside corners without filler and then went back and added filler, if you didn't completely melt your first pass weld bead and dilute the puddle with the added 4043 filler rod, there is a pretty good chance that you will have a crack underneath in the first pass weld bead.

Just the metallurgical nature of the 6xxx aluminum alloys.

Another Lincoln quote, from a few pages farther along in the same document:

Good info.

Like I said I was using some unconventional techniques that at least got me able to fuse the stuff together and at this point its starting to look a little more respectable. But I had a feeling something was up.

Thanks

 

[600SL]

2% Lanthanated for everything. Really. I think tungsten and helium (heliarc) got along better and I suspect it was a carryover with Argon.

HF sells a $9.00 three piece diamond surface grinding wheels. They are about an inch and a quarter in diameter. I chucked one wth the shaft provided in the kit to a mounted electric motor that has a three jaw drill chuck on the shaft. It grinds the point beautifully and I haven't worn the first one out yet. I can't imagine the synthetic diamond dust surface causing any contamination.

It seems to be the general consensus both here and elsewhere that 2% Lanthanated is the best all around tungsten. I even saw a video on Welding Tips and Tricks where he used a sharpened Lanthanated for aluminum with a Lincoln Square Wave 175 transformer machine just like mine.

 

[600SL]

Well

New machine, New helmet and a real change in the final product.

Old machine Lincoln SQ wave 175 Transformer

New machine Lincoln SQ wave 200 Inverter.

Huge difference in welding. I actually feel like I'm cheating. The 120 Hz helps and the pulse is a real big plus.

I'm by no means a pro yet or even ready to sell my work but this is a big plus for me.

One of the things that I did put to bed from the beginning of this thread was that cleaning had nothing to do with the problems I was having. I'm not saying not to clean for any critical welding but all welding performed this weekend were with the same material but and wiped off.

I ran a few beads on the same material. I found setting the machine to ~ 95 Amps with an 8Hz pulse was the optimum for my first try on this AL. If I did happen to burn through very easy to fix with the pulse and even easier to fix if I reduce the frequency to 1 Hz.

My helmet was also giving me trouble. I purchased the top of the line Lincoln Viking. Vision was significantly clearer with the Lincoln over my 20 year old Jackson and the large lens lets me use my progressive lenses and therefor no need for cheaters. I also tried an Optrel 2.5 which did not work as well due to the smaller lens. Although there were features on that I really liked.

With the new Lincoln helmet welding AL is really easy to see only occasionally requiring the need for extra task lighting. For steel TIG I still require task lighting for just about every weld.

I also got a new Lincoln MP210 MIG welder. With that I cannot see a damn thing even with an allegedly 1000 lumen cordless light placed 1 ft away. So I just ordered a 2300 lumen 45W off road vehicle light from Super Bright LED's that I am going to try. Thats about twice the power of an standard automotive headlamp.

I will keep you posted.