TIG Anguish :( Can't Fillet or Lap weld Aluminium

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Originally Posted by NomadicD3

... Now all that said and just guessing really i'd say that you need to start with attaining your molten pool on the main piece of material then wash across to the edge of the other piece, but once you have your molten pool on the main piece add some filler wire then wash to other piece of material edge.
Mate i have no idea if this will help but it's what i do and i've been getting some really good welds. That said for the first few days i was where you are.
Keep at it it's worth the effort!!!!!:)

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I'd go along with this method too. Let the filler wire melt to bridge between your pool on the base material and the top piece. As you form your main pool, watch the piece on top as it will heat quickly (as you've found) and alter the torch position and angle to control it. Once the bridge is formed, use a combination of torch position and the addition of filler wire to help control the heat.

If you need to you could try clamping a heavy piece of steel across the top of the job about 1" behind the area to be welded and running the length of the weld. This will act as a heat sink and reduce the likelihood of the top piece pooling away from the edge.

I've done similar welds when I constructed my ally boat loader for the roof of my Disco. I really didn't find these welds too difficult - probably had a lot to do with the hours of practice I did on scrap to get a feel for the machine.

My TIG has no fancy settings. The AC is a straight 50-50 balance at 60Hz - no option to change. I think this worked in my favour as I had nothing to fiddle with except my technique.

Lots of practice ...

I have gone through a whole bottle of Argon practicing :eek: Wonder how much that will be to refill....

NomadicD3 - if you are nomadding past Adelaide call in and give me a quick lesson. I will pay you in beer or wine!

It is only my first tank of Argon, so guess I will just have to put in some more torch time. I did have a bit more success, and managed about 3 or 4 sections which joined nicely, and just when I thought I had it sussed, I lost my mojo and it all turned nasty again.

Am going to take my sample welds into BOC tomorrow when I get more gas and ask them to show me how it's done. They sold me the Kemppi, so hopefully they might give me a few pointers.

Thanks for all the advice and words of encouragement. Will keep at it, as when you get one right it is a pretty good feeling :eek:

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Originally Posted by NomadicD3

- use the correcdt type of filler rod 5356 is great for structural ally ie:6xxx or 7xxx series or for 5xxxx series 4043 or 5356 will do fine but 4043 has better weld properties.

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How do I tell what type of Aluminium I am welding? It is just some Chequer plate I got to practice on from the local scrap yard. Looks mint, so it is not dirty at all. I am however not cleaning it with white spirits or acetone. Is that important?

How do I find out what "series" the chequer plate I'm using is, and therefore what rods I should use?

BOC sold me a 2Kg pack of 5356 as they said this was the most common one to use.

Got some Ceriated (sp?) tungstens and a bigger pink gas shroud (up 1 size) today, so will be out in the shed later tonight trying that out.

Bloke at the welding shop suggested 7L/M gas probably wasn't high enough, so will try at 9 or 10.

Hi Spud, If only i had read your post last week B4 i drove back from melbourne to perth:(.
I just checked and i'm reasonably confident that all ally chqer plate is 5052 h34 but not 100% on that. Won't matter 5356 filler should work fine.
Stick with the zirconated tips best for ally. ceriated is more for ferrous metals.
Gas should definately be about 10ltrs/ min particularily on fillets where the gas can vent through the gap in the materials.It's been a few years since i was tig welding in a workshop{ ex sheet metal wkr} and the machines have changed alot with the invertor technology but gas flow and filler rods are still the same.
And funnyily enough i'm looking at my last gas bottle bill for a refill from boc , it's $156 for an E size bottle.
Not sure i can help much beyond that spud. Looking at your photos your speed looks good. Hey go to utube and do a search for tig welding tips i think there is a welding tips and tricks guy on there somewhere.
Good luck mate keep at it :D.
Nomad or not mad u choose LOL

Ah bugger - that was bad timing :D

Actually - I just read the invoice from today and it was not Ceriated they sold me - it was Thoriated (ones with orange ends) so I think they are OK for AC work. MIG is quite a bit simpler - that's for sure.

I think you may be onto something with the gap between the plates. I can see that the gas might be escaping through the gap instead of flowing over the metal, so that is something else to change.

Hey spud, my memory's not so clear these days but i'm almost certain you want zirconated tips, the ones with the white tips and make sure they the good quality ones, there are some chinese ones that have a kind of off white tip on them and they are sh#*...:mad:, learnt from recent experience:mad:
Also i assume you are using 2.4 mm tips?
3mm ally can be welded with 1.6 mm tips but is alot easier with the 2.4.
True mig is alot easier but i did alot of reading about ally welding before i decided to take it up again and the effect of the true purity of the weld has incredible impact on the strength of the final product and looks heaps prettier LOL.
I'm about to start building an almost completely aluminium TRUE offroad trailer and have spent many hours researching relevant information over the past 8 months and without question mig welding would take half the time to build but sacrafice way to much weld purity for my liking.
Cheers mate

Well.... the different tungstens seem to have made no difference at all. Am still destroying perfectly good aluminium sheets at a prodigious rate :p

Have put the argon flow up to 10LPM but can't see any difference.

It's 1:15AM, so time to give up for another day and think about it again tomorrow.

Ummm,
not a GTAW proponent (I think for 3mm Al you should just reach for the glue gun!!! MIG)
but anyways when you say "a whole bottle of Ar" tell me thats not like a D or E size bottle because if it is that seems way thirsty for dialing in practise - unless there are sheets and sheets of practise run we havent seen yet!!!!.

Is it possible your reg is playing up and your flowing too much gas causing turbulence and poor shielding? My understanding is turbulence is an even bigger issue with GTAW than SMAW?

Ive had a regulator go bad - never dropped or damaged. Three D size bottles of Ar through it and on the 4th the second stage just let go, gauge stopped working and would almost free flow. If you have a spare reg may be worth trying?

Steve

The bottle size is sort of navel height. Just fits in across the back of a Disco. Not sure what letter it is.

It has done quite a bit of steel TIG welding prior, so shouldn't really blame the Al welding solely for using it all up, but yes, I have done a lot of practice and wasted a lot of gas and filler rod :(

I have got a roll of Al wire and a new teflon 'sheath' for my MIG to try on Al, but not got around to testing that yet. I thought TIG would be neater and more controlled so was trying that first.

I did a dumb thing for 15 minutes last night, before I worked it out. I moved the welder on to the bench so I could change the controls more easily, and it was doing very bad welds full of contamination until I realised the cooling fans in the welder were blowing straight across where I was welding. TIG without Gas (or at least when you're blowing away your gas) is very nasty :p