TIG welding aluminum

[robs660]

I am a pretty good tig welder on steel, and I am finding aluminum to be really difficult to weld. I have a miller Syncrowave 200 and I am trying to weld on 1/8" aluminum flat stock. I am looking for anyone who can give me some advice so that I stop flying through filler rod and gas and I am running out of scrap to practice on.

Help!!!!!!!!!!!!!!!!!!!!!!!!!! Need to repair an aluminum roof on my Kubota

 

[DrRick]

i am sure that you are welding using the AC instead of DC current. It also requires only argon gas, not the 25/75 mix. not meaning to step on toes.

 

[moship]

Remember to ball the electrode and to use the correct ones.

The other thing to think about is that it takes a lot more heat to melt through the aluminum oxide layer then it does to melt pure aluminum. Therefore need a lot more heat to get it started and then back off on the pedal.

 

[sizzami]

what type of tungsten are you using they are colored at the end we say red top green top and so on red isnt for alluminum green is if youre using green then by all means ball it if u get gold grey or orange u can use them for any metal and should sharpen them not ball them having said that I agree that you are probably just starting too cold and allowing the work to get too hot

 

[Mechanos]

The metal need to be CLEAN. Get a stainless steel wire brush and write "Aluminum ONLY" on the handle. Do not use this wire brush for anything else except aluminum or it can pick up contaminants that will be deposited on the aluminum you are trying to clean.

I should also note that different alloys of aluminum use different alloy filler rods. Some alloys of aluminum just don't weld very well at all.

 

[Ford tractor]

CLEAN metal is needed. If you are using an abrasive wheel to cut the metal, that can be an issue. The heat forms thick oxide quick. Saw cut, file to bevel.

 

[RoyJackson]

Once the puddle forms, you need to move pretty quickly. With aluminum, you won't have that tight bead ripple that you have with steel.
Also, keep the filler rod close to the arc so it's just on the solid side of melting.
With 1/8th sheet, I suggest you use 1/16th rod.

As Mechanos wrote, some alloys don't weld well. This includes most of the tempered alloys. But I'm going to make and educated guess your roof is a 5xxx or 6xxx series aluminum due to their workability (in forming and stamping).

 

[Wayne_H]

Do you have any pictures and can you tell us your settings? For 1/8" I'd start with 125 amps, AC of course. On my Dynsasty I'd run maybe 100 Hz depending on the type of weld. I use ceriated tungsten all the time (orange) and I use 3/32. On my Dynesty (Invertor) I do not ball the tips, sharpen it at a 20 degree angle or so.

Also, what type of aluminum? With aluminum you need to move WAY faster than with steel. Also, what cup are you using and what is your argon flow set at? If the aluminum if new, I don't wire brush it, the cleaning action of the AC removes the oxydation.

Wayne

 

[robs660]

I am using the green tip electrode with a balled end. I have the amps set to 175 max and was at 60% on the peddle. I am using the same cup and flow that I use for steel and I running 100% argon. The photo was the best I could do. It's strong but ugly and I am not happy with it

 

[Wayne_H]

In my opinion, you are not close enough to the corner, and you are lacking shielding gas. What cup are you using? Are you at 15 CFM or so?How far out is the electrode sticking?

Wayne

 

[busby]

ck your pm's

 

[Wayne_H]

can you stack dimes on a flat surface? Aluminum is harder than steel, it does not fusion weld like steel.

Wayne

 

[robs660]

I can not yet stack dimes on aluminum. Should I be in AC or DC with the green electrode. I know my gas cfm is good

 

[Gary Fowler]

You need to be in AC with high frequency turned on. The photo shows that you have some contamination. Are you using high frequency? The photo doesnt look like it, it should hear and feel the vibratory effect of the high freq. unit working, this aids in the fusion process.
THe black sooty stuff is contamination and will keep your metal from adhereing. If you strike an arc and get that black soot, it isnt clean enough. Use a stainless steel brush to clean the metal and then wipe it down with Acetone. Dont forget to clean your rods also. Then dont touch them with your bare hands, use a pair of clean cotton gloves so you dont get oil from your skin on the rod or plate. Use a large cup size 10 or more and tungsten stick out should be about 1/8". I think you said you had the balled end so I assume that you know how to do that by setting your machine like you are going to stick rod and striking an arc with your tig rig. The ball needs to be perfectly round on the end and not off centered or you will get some erratic arcing.

 

[captkipp]

I weld aluminum as a profession.
Follow the guidelines with your Miller machine.

As a base use 190-200 and pedal the amperage to get the base material to puddle FIRST. This should be around 150-175 for non-anodized aluminum plate. THEN add rod to the front of the puddle and work it into the base metal by moving back to the previous "button" on the weld bead and then forward before adding rod once again. Repeat.
Your picture shows a lack of shielding gas coverage: Check you distance from the cup to the base metal AND the CFM of the ARGON gas. It should be 15 or so. IF you're welding outside of a sheltered area with a breeze blowing this WILL greatly affect the shielding gas' ability to cover your weld.
The base metal alloy is a big factor in the choice of filler rod. However as stated by one of the other posters, I would guess that it is a 5xxx alloy.
Either 4043 orm 5356 rod will work.
Stick out, the measure of distance your electrode is past the front edge of the cup, plays an important role as well. while your learning ( and even after) keep the electrode even with the front edge of the cup or no more then an 1/8th of an inch out.
The fillet weld you are attemptinig is generally not given to students of aluminum welding until after they are relatively proficient in the flat and lap welds. Simply put it takes some time to learn and it is pretty tough top figure it all out on your own. But...
Having someone who knows show you can make a HUGE diffence. Check out Miller's website Miller - Welding Equipment - MIG/TIG/Stick Welders & Plasma Cutting and click on the "Resources" tab. you will find videos that are FREE and they can help you with your technique.
I'll assist you as much as I can via remote control.
Good Luck ! DL

 

[Wayne_H]

I can not yet stack dimes on aluminum. Should I be in AC or DC with the green electrode. I know my gas cfm is good

Rob: I don't mean to give you a hard time, but you might want to find a local welding shop to do this. Your question of AC/DC for aluminum is more than basic, and frankly indicates you probably have not done a lot of TIG... TIG takes a bit more practice and know how than MIG, the welder at a local shop who does it 8 hrs a day and charges probably 40 bucks an hour will make that look great in no time, plus I suspect it will cost under 50 bucks..

It almost looks like you are on DC????

Wayne

 

[robs660]

None of my projects are ever important enough to take out for welding. I want to learn to do this as I have the equipment and I understand the theory. I would rather burn through a bunch of rod and material then just send it out I could always mig but I really want to learn and understand how to do it. More practice will be coming tonight

 

[Wayne_H]

OK, well I suggest getting a book from millerwelds.com and doing some reading on the topic, it will set you in the right direction. You also may want to take a class or hire an instructor. TIG takes a bit of practice. MIG welding on Aluminum is not easy either.

BTW, what gas are you using? It needs to be 100% argon.

regards

Wayne

 

[RoyJackson]

OK, well I suggest getting a book from millerwelds.com and doing some reading on the topic, it will set you in the right direction.

I'm going to add to get a few pieces of scrap aluminum and learn horizontal butt and lap welds initially. Between .06"-.12" will work. With thinner gage (.06" or less), use "Soft Start" if your welding machine has it. Another thing you can do is strike the arc on a piece of brass and carry it over to the workpiece.
When doing a butt weld between two thinner gage practice pieces, keep a small gap on the end opposite of your start point...they'll pull together as you run the bead.
I'm no expert by far, but I was certified as an aircraft TIG welder in the Navy. That's been over thirty years ago.

 

[c23380]

Welding aluminum?? Though a little harder than most welding it is good to learn something new. One one rule to remember about Tig. CLEAN, CLEAN,CLEAN. When I say this I am talking about the base metal, the filler rod, the electrode, and most importantly the shield of argon. If the wind or a draft blows the shield away.....bad. If you touch the electrode to the base metal......contamination. If the base metal has any oil........contamination.If the filler has oil.......Ya see what I mean. I love to tig weld and it just takes some time to figure out where the contamination comes from. AC with high freq for arc stabilization, a little practice and you can do it. I like the miller website suggestion others have made. Good reading and some practice and you will be able to do it.

A few tips:
If you touch the electrode to the base, Break it off and re-ball it.
if any soot appears, or a green glow, SOMETHING is not clean.
Too much shielding gas sometimes will cause more harm than good.