How do you gage penetration when welding aluminium? I'm trying to weld some 1/16 5052. Two passes look similar to me but when I bend the butt joint, one pass has little penetration while another burns through. They both looked similar to me during the weld process. Is puddle width the only visual clue or is there something else? Should anyone be able to do this with practice? I jumped to 1/16 because I have illusions of building a motorcycle gas tank.
- Thread starter mcman56
- Start date
Memmeddu
Member
- Messages
- 5,345
- Location
- Italia Sardegna
Generally speaking aluminum Tig welding if you see red at the edges of your cleaning zone you are using way too much current.
Penetration may change up on two main parameters and the welding start .
But again not rocket science you just want to see the edges of the bead well tied in.
Now for your fuel tanks you are using a too thin material IMHO because you really don't want to use less then 2mm aluminum for a fuel tank because both heat expansion and contraction plus vibrations may lead to premature cracking.
I weld fuel tank frequently at work and they are thicker than you think ranging between 2.5mm up to 6mm for the bigger ones but the average fuel tank is 4mm thick.
Anyways I'd go with about 60 or 65Hz for the frequency and if you want to try to weld what you have in the pictures I'd go with about 40A or less and just wait to see the puddle forming and wait a bit prior to gently dab filler in it.
Done that you essentially have to run and release the button on the torch to cool down the puddle if it starts to become to hot.
For this reason you might want to set a 5 second downslope.
1 or 1.6mm green tungsten.
And 60% negative balance should be enough but balance is something more personal than objective IMHO.
I like little bit more positive phase but that's because I do repair jobs in the machine shop and really never weld perfectly clean aluminum
Generally i go for go hot and fast, if you are burning holes, a lot of time you're traveling to slow and not enough amps, fit up must be perfect especially on lighter material, 2mm and under, if you're going to slow the material in front heats up too much and you end up with a hole, i find a sweet spot for me at 2mm is around 120 hrz,
i watch for the rise and sink of each dab when the pool just starts to sink add a dab which sits up then starts to sink then add another dab snd so on, you know youre getting good pen when you see this hapen
BrokenBiker
Member
- Messages
- 11,225
- Location
- Newport, South Wales
experience is pretty much the only way to know whan you are doing it right, lots of practice with fit up, travel speed, filler addition, settings etc...
aluminum is a huge heat sink, even when thin and if you are travelling too slow the heat builds up quickly and ive found the root of the weld will start to open up on you and the filler will wick to each side and not touch the root, alternatively if you are set too low, you then have to travel slower, however when adding filler it cools the weld again which will hinder penetration...if you are using a pedal, set the amps maybe 10% higher than you think you need, then light up at full pedal, get the puddle going, add a few dabs of wire and then ease off and get moving, keep the amps up just enough you can see the puddle biting in to the parent material then add filler just as it looks like its getting away from you, this chills the puddle a bit and lets you regain control while giving a pretty good gurantee of penetration. if you are using a torch sitch, set the amps where you think they should be and give yourself a 5-8 second downslope with the finish amps at about half your working amps, upslope at maybe 2 seconds so you can let go, it will cool enought o stop it melting through but you can get the heat back quickly when needed.
this of course is only my opinion from learning to tig mostly from advice on here, videos and trial and error til i found a technique that worked for me. im by no means an expert and my welds would attest to that, but nothing ever falls apart after ive told it to stay put
aluminum is a huge heat sink, even when thin and if you are travelling too slow the heat builds up quickly and ive found the root of the weld will start to open up on you and the filler will wick to each side and not touch the root, alternatively if you are set too low, you then have to travel slower, however when adding filler it cools the weld again which will hinder penetration...if you are using a pedal, set the amps maybe 10% higher than you think you need, then light up at full pedal, get the puddle going, add a few dabs of wire and then ease off and get moving, keep the amps up just enough you can see the puddle biting in to the parent material then add filler just as it looks like its getting away from you, this chills the puddle a bit and lets you regain control while giving a pretty good gurantee of penetration. if you are using a torch sitch, set the amps where you think they should be and give yourself a 5-8 second downslope with the finish amps at about half your working amps, upslope at maybe 2 seconds so you can let go, it will cool enought o stop it melting through but you can get the heat back quickly when needed.
this of course is only my opinion from learning to tig mostly from advice on here, videos and trial and error til i found a technique that worked for me. im by no means an expert and my welds would attest to that, but nothing ever falls apart after ive told it to stay put
BrokenBiker
Member
- Messages
- 11,225
- Location
- Newport, South Wales
To be honest, on 1.6mm material, it should be harder to stop the penetration than to get full penetration...
Memmeddu
Member
- Messages
- 5,345
- Location
- Italia Sardegna
The same thing I've thought while reading the previous reply
