Just started welding aluminium - all comments highly appreciated

[Rein]

Hi all,

I've been coming back to the forum for several years now and just decided to sign up and become more actively engaged. I think this forum is great cause its full of information and advise!

I've been welding mild steel in my free time for a while now and decided i wanted to have a go on aluminium. If I can learn fast enough i'd like to try and finish a project in about a month. But we'll see how that goes.

So anyways I've read a lot of posts on the forum and watched videos by mr. tig and weldingtipsandtricks. Basically anything that said TIG aluminium. After that just took some scrap pieces and started experimenting with different settings and technique. I'll post some pictures of what i've done. In a few nights I think I made decent progress, at least I m happy with it and enjoying to learn ally. Any comments are highly appreciated!

I use a kemppi mastertig, argon shielding and no foot pedal because i don't have one.

So this is how I started out. Piece of 40mm x 40 mm L profile, about 2mm thick. Tried out different amps and ac balance.

After this i tried some butt welds on 0.8 mm thick 25x25mm tube. That turned out to be a big disaster, for the biggest part because of the edges running away before i could get any filler in. Don't have any pictures thought.

So figured out, welding straight on anodised without cleaning doesn't work ;-)

This is starting to look alright in my opinion. Did a bit of cleaning with scotch bright after welding.

For my project, a small luggage carrying rack for a motorbike, I intend to use 18x1,5 mm tube. So picked up a length of 6060 18mm tube.

First go at the 18mm tube.

Second go, also cleaned with scotch bright after welding. Looks a lot better when you clean it up after.

Same weld, other side

And one from the top.

All the 18mm tube was welded with kemppi mastertig. Ac 100hz / balance set to -55 (this is a bit different from other machines because it has some sort of auto-balance function) / 6 liters/h argon and 50amp most of the time. By the time it all warmed up went back to 35 amps.

What do you guys think. Any tips to try make it look better i'm gonna try out soon, and i ll post pictures of any improvements.

Do you think these welds are structurally sound? If i look inside the tube i can see the weld 'coming thru' on some places.

Thanks! Rein

 

[hotrodder]

Do you think these welds are structurally sound?

To be blunt no. Don't get me wrong you're off to a good start but it's gonna take a while to get to grips with the constantly changing angles of attack on tube. Not keeping up with them effects everything... arc length changes, filler starts to melt before it meets the weldpool, even shielding quality etc.
While a brute force attack might result in the tube getting properly mangled before the weld lets go fatigue is a very different animal and the cause of most failures in the real world hence the BFH not being used so much for proper destructive tests... http://www.mig-welding.co.uk/wiki/Weld_Testing

This thread might be of some use... http://www.mig-welding.co.uk/forum/...s-please-give-advice.40506/page-5#post-452447
Craters... how much slope out/down time do you have set and where's the final/crater current set? Looks like you either need more slope time and lower crater current and/or add an extra dab wire as you finish the weld and keep the torch moving until the weldpool freezes

 

[BrokenBiker]

they look ok but as said i think you need a bit more practice before moving onto something that could throw luggage all over the motorway.

keep practicing on flat stuff in various positions. You need to be able to weld in position before moving on to something where you are constantly adjusting torch angle, or atleast that is what i have found anyway.

 

[Rein]

Hotrodder, brokenbiker,

Great tips and I totally agree. I need a lot more practice. Gonna try and get a few hours in today.

Hotrodder, I went through the threads you quoted and all the threads that were quoted in there. For now i'm gonna skip the weld testing and just try and improve on technique. Once i get to better looking welds from the outside we ll look what's on the inside.

I identified several things I think I'm doing wrong and therefore i can focus on improving:

1. You show an example of doing a basic butt weld, and the effect the electrode distance has. I recognize the getting two different puddles, which I then join with filler. Especially when tacking the tubes together. So I ll focus on smaller electrode distance, to try and get the heat more in the bottom of the butt weld.
2. Indeed it's hard to maintain the same angle going around the radius of the tube. I'll get some practice on flat and basic buttwelds first. Also i recognise that when i don'n follow the radius, the angle changes and therefore electrode distance effectively increases....
3. Goinig to see what happens when i get a bit more balance on the penetration side and increase the frequency a bit. Both aimed to try and help me get the heat in the bottom of the butt weld.
4. Sometimes I don't manage to get the filler directly in the puddle. A little bal of filler than just sits on the edge of the puddle, and I have to use the torch to 'melt it in'. Try and avoid that. Think it s mostly because of torch angle again.
5. Slope out/down time. None at all at the examples above. Really just forgot about it. Silly me.... About 2-3 seconds ok?? My machine gives the option to slope down, i don't think i can use an amperage though. It just slopes down to zero. While sloping down I just go in the reverse direction with the torch? I do that welding stick on mild steel to avoid craters/flat spots.

So lots of stuff to work on!

One more question. In the example of you welding two tubes together you say you take 4 runs of a quarter pipe to get al the way round. Is there anything wrong with doing more shorter runs to allow repositioning and changing settings?? Especially on the top and bottom I need a little less amps than in the corners I noticed. So for me that means stopping, turning the dial on the machine and than restriking an arc.

 

[Rein]

Got some practice in and learned a lot today

Used some downslope, about 5 sec. Which is maybe kinda long? But it worked to try and avoid the sink hole / crater at the end.

Compare the one on the left where I did, and the one on the right where i didn't. Also i read someone saying to move the torch in small circles. That seems to help aswell.

As hotrodder said, a very small electrode distance helps to get the heat all the way down in the corner. Far from perfect, but i like the way the weld sits in the corner.

Contaminated filler rod!

Compare the two images. They were welded with all the same settings and on the same pieces. Only difference was the filler material. Turns out i've been using filler material which is over 10 years old. I suppose it was oxidized so much it messes up my welds.


Got some questions to:
1. About cleaning. The tubes I bought a few days ago, I can weld ok without any cleaning before hand. The plate material I got at the same shop definitely needs cleaning with scotch bright to get a descent weld. I noticed the plate has a very shiny finish, and the tubes are dull. Could there be a protective coating on the plates I got??

2. The speckles / rough spots in the surface of the weld. As if there are small flakes in the weld. I also see those in some welds with the clean filler. Seems to me that happens when i put to much heat in. For instance slower travel speed, or less filler. Could that be the cause?

3. Some of my welds are very shiny. Others are dull. Shiny is better?? What makes a weld shiny or dull??
Below is an example of one of my shiny welds. The black stuff comes from dipping the electrode at the end i think. But the whole weld is very shiny.

Thanks!

 

[hotrodder]

Nothing wrong with shorter runs as long as the stop/starts are tied in properly, i only did that weld in 4 bites as it was a small piece laying on the table i.e. on a real part access dictates things and i may be able to get around the joint in three or less if access is good or need 6 (some of them making a mess cack left handed) if it's a right PITA with stuff in the way

Slope times... they can vary lots with different jobs, materials and personal preference. A bit OTT for the moment but can even use much longer slope out times to account for heat soak and use slope up to counter thermal inertia i.e. on ally can set it to above 100% for a 'hot start' that then comes down to welding amperage although that sort of thing is more useful for repetive work or even automated TIG than manual stuff due to the time it can take to dial everything in. This is why a foot pedal is soooooo useful (as long as you're not grovelling around on the floor) because it lets you do what you want with the amperage as you weld.

The plate you got sounds like it may be clear anodised, anodising is basically an artifically grown layer of ally oxide...
Sheet, plate and extrusions (tube/angle etc) can all be anodised or mill finish. In the case of mill finish extrusions tend to not be as clean/shiney as rolled stuff. With practice you'll be able to spot anodising easily enough, feel is another way as the surface is generally slicker and your hands don't go black from handling it

Surface/texture/shineyness of ally welds... http://www.mig-welding.co.uk/forum/threads/surface-of-ally-weld.24510/#post-267917 The black stuff is 'weld smut' basically oxides from vaporised ally (touchdowns, filler wire into the arc or tungsten etc). While manky old filler wire may not have helped i'm wondering if a large part of the difference in your comparison pic is two different flavours of wire? Kinda likes like 4043 versus 5356

 

[Rein]

Checked the filler today. Indeed the 'older' filler I have is 4043 (brand unknown) and the newer filler is Lincoln Electric 5356. So the difference in the comparison pic might very well been caused by the type of filler instead of the age oxidisation of the filler. Anybody who is familiar with the difference in filler??

When I use the 5356 filler on 6060 tubes, the welds sometimes come out shiny, sometimes dull. What i've noticed it seems to have something to do with travel speed. Perhaps when I travel to slow there is to much heat buildup, and part of the weld solidifies or cools when the torch and therefore the argon has already moved to far away?? I'm just guessing here, since I only have a few night's experience welding alu.

Hotrodder, again many thanks for sharing your knowledge! Your advise is very useful. For me it helps a lot to understand what i'm doing and knowing what to look for when practicing.

 

[BrokenBiker]

Perhaps when I travel to slow there is to much heat buildup

this is pretty much the casue of the dullness afaik. its the same with stainless steel too, hang around too long or use too much amps and it will burn the chromium out of the weld with stainless, same principle for ali.

it will all come with practice, keep at it, wont be long till you can jusdge how much speed you need with how many amps and so on

 

[Rein]

Great! Can't wait to get some more time in. Everybody I know says welding ally is terribly difficult. But the few times I get some good welds its really rewarding. Also i feel the control over the puddle in a way is easier than mild steel.

Once i make some more progress I'll post some pics. Or ask questions, lol.

btw, what kind of welding, projects, work do you guys do?

 

[hotrodder]

Checked the filler today. Indeed the 'older' filler I have is 4043 (brand unknown) and the newer filler is Lincoln Electric 5356. So the difference in the comparison pic might very well been caused by the type of filler instead of the age oxidisation of the filler. Anybody who is familiar with the difference in filler??

When I use the 5356 filler on 6060 tubes, the welds sometimes come out shiny, sometimes dull. What i've noticed it seems to have something to do with travel speed. Perhaps when I travel to slow there is to much heat buildup, and part of the weld solidifies or cools when the torch and therefore the argon has already moved to far away?? I'm just guessing here, since I only have a few night's experience welding alu.

Filler wire differences... http://www.mig-welding.co.uk/forum/threads/alu-rod-question.39596/#post-437963
As well as heat input (too hot/slow) shielding quality can also make a difference, for example with an outside corner weld/small dia tube the geometry of the part encourages the argon to flow away from the weld. This is one of those times when less is more as many people will turn the gas up when they suspect a shielding problem which often makes things worse. AC balance can also effect things

btw, what kind of welding, projects, work do you guys do?

http://www.mig-welding.co.uk/forum/useralbums/hotrodder.4093/list

 

[HughF]

4043 always looks like that, 5356 should be a go to filler on wrought stock, save the 4043 for cast

 

[Brad93]

Clean your filler rods with acetone and the aluminium with acetone. Keep your tungstens sharp if you can. Use a gas lens. If you dip the filler, stop, cut the filler, change your tungsten and start again.

 

[Rein]

Great tips guys, i ll give it a try!

 

[Rein]

Got some more practise in. With mixed results. Guess i now just need to invest a lot of time!

 

[imbrokers]

Hi
Im no expert, after a year of getting aluminum wrong, I finally got it right

Power - depends on thickness etc but I am using like 35-40A on 1.2mm aluminum. (I take my time)
AC current
100% argon
pulse + - 150 pps
duty 50%
cleaning 50%

this is where it gets important
Pregas - a must at least 1 sec or more - i have found without pregas the tungsten balls up on first strike.
Postgas - min 5 seconds I use 10sec
Gas flow - 10L/min or more

And then this is where it gets more important
Tungsten is White zirconiated - no other one worked for me on aluminum.
diameter is 3.2mm or 4mm (thicker the better, it helps prevent balling)
tungsten point is sortof sharp but the tip is sortof a sharp bullnose, not a needle point and not a flat point.
And a gas lense with the diffuser mesh - made a huge difference.

wire brush everything
Acetone everything
acetone the filler, I run a fine sand paper with acetone onto the filler, this alone has stopped the sparkling, I sandpaper with acetone all my fillers
even for stainless and mildsteel.

the filler needs to be away from the arc heat when welding, if it is close to the arc it sorts of blobbs up and goes dull and when you dip it in
the puddle sorts of stops. I weld slow,at low amps it takes a few seconds to get the puddle going, maintain the pool at all cost, pause, dip in filler, create a

dime, then move puddle, pause, dip, move puddle etc

for me at least, if I use higher amps, I find myself trying to catch up, burning a hole sometimes and the stack of dimes are terrible looking.

I can now weld aluminum, although I still cant get all my dimes to look the same.

Hope this helps someone.

 

[Rickardo]

I am no expert in TIG welding either I just started doing an aluminium welding course and I have learned that a GTAW(Gas Tungsten Arc Welder) is the best method of welding aluminum.The TIG process utilizes some of these shielding gases, they are argon,argon/helium and helium.Argon is the most superior gas for welding metals.It operates at a higher arc voltage and makes the arc start more easily and is most commonly used to weld mild steel,aluminum and titanium.You add helium to generally increase the heat input and for the high speed welding of mild steel and titanium.It increases the welding speed upto 40%.The argon and helium combination is mostly used for a hotter arc in welding aluminum and aluminum alloys.It’s also used in automatic welding applications.

Training Company Link Removed

 

[HughF]

Pre-moderated? He should be banned!

 

[Wozzaaah]

Why? he may only be a learner welder but he's very good at copying and pasting and we welcome copy/pasters with open arms on here.

 

[Richard.]

Why? he may only be a learner welder but he's very good at copying and pasting and we welcome copy/pasters with open arms on here.

Ha yes. Ive noticed