Expert alloy tig welders. I need advice

[Llama]

May have been mentioned earlier, but have you blown out your cylinder valve to make sure there's no crap in it?

[Stu]

I would try and wind down the pressure on the center of the reg under the cap - leave the flow rate at 4-5 and see if it makes a difference.

[evil_si]

Get some Alloy acid and treat the area of cast before welding,

I also grind a slight beval on the cast runners using a sanding disk or flap disk.

Regulators i find the flow meter type good. Has a small plastic ball that floats at the lpm that its putting out, a lot more accurate

[sentra]

struggling at the moment on alum tig, speficially,

so everythings stainless wirebrushed & acetoned, at this point i still dont care about finished weld asthetics,

but, so i tack it around, everythings sweet, then start welding, everythings sweet, but then...

"out of the blue (to me!)" i get that inclusiony grey? crud like in yoeddys first post and from then on the rest of the weld is like that, unless i stop, move foward 1/4inch, then start again/go fix that shit up later/for what im doing i dont care about it, it is just hard to keep welding as a skin? forms over the metal.

i cant imagine it being much cleaner to start with, does this start with overheated material mabey? the tungsten hasnt been dipped or anything/works sweet otherwise.

rest of gooing metal togther looks exactly like eddys lower pics, it works fine for purpose but people laugh at me so this thread has sparked desire to learn!

[kpr]

what are you trying to weld? sounds kinda like the material to me. once you start to get some penetration, the shitty contaminated ali beneath the clean surface, gets into the weld?

i had some welds looking just like yoeddys pics the other day. bran new ali, nothing i did would fix it. turns out the gas i was using was contaminated. dont ask why.. it welded fine on mild and stainless. but ali far more picky

[Llama]

Water in your bottle?

[yoeddynz]

I think I know what you mean- I have had the same and usually its when the material just gets too hot. I think. put up photos. Next time I do or get some shit thing happen to my welds, ha..next time I weld then, that I'm not sure about I'll take photos and others can say whats up.

[eke_zetec_RWD]

Yea get a flow tube regulator. Much better

[yoeddynz]

yeah I will do. The one I have is a shitty cheap item Im sure.

[Seedy Al]

Although I am in no way at all an Alloy welder, to me Sentra Dave, it sounds like what alloy goes like when you get to melting point.

I dont know if this is meant to happen when tigging as I have never done it.

[sheepers]

yea, it sounds to me like its getting too hot.

when its too hot it starts to burn, it goes all grey and powdery on the top and you cant weld shit, cramming more rod in wont help much either.

it takes way more energy to get the job hot enough to weld than it does to weld it. depending on the job i usually pre heat it (with the tig, just waving the torch up and down the weld path) then give it a quick wire brush, turn down the heat and weld.

you'll always find the end of the weld behaves differently to the beginning as the job gets hotter.

start at the small pointy bits that will melt easiest. if you leave them to last they will just run away.

[sentra]

you guys are so cool, need to find some more jobs to weld

[Escort Engineering]

May have been mentioned already but when welding alloy grind tungsten to a ball or on a slight beval , gas flow around 7-8 litres a minute and use a gas lens with a number 6 or 8 ceramic so you get fairly good gas coverage , when the pool in the alloy is astablished you will see it go very matelic silver like dull chrome you will see a swirl in the weld pool this is when good heat has been created and the two pieces your are joining should start to fuse, start traveling adding wire if needed but be cautious of the heat as you move along the weld you will have to start traveling faster or turn your amps down. Hope this info is of some help .

[EURON8]

Lets drag this back from the dead.

Few questions.

 

Got a tig, came with Reg.

 

Absolutely ripped through the first 2 small bottles. Should have had ~4 hours welding@8Lm per bottle based in bottle contents of 1.92m3 (or whatever number about there that is written on the sticker). Pre and post flow turned down, i know its not flowing for ages. 

 

 

Got Another bottle now so chucked the supplied reg on. with out connecting to welder.

 

at 10Lm flow chucked a pressure gauge on the outlet and get 16psi

Then repeated the process with a new BOC 6000 reg with dial flow gauge set to 10Lm and get >10psi output pressure.

 

I cant find anything online at the moment that talks about output pressure. Just flow. But my understanding is that flow is flow. 1litre is 1 litre but if that litre is under more pressure then more gas is being used????  Have a flowtester and its showing the right number at the nozzle, but wouldn't that be a different reading depending on Pressure

 

 

Im lost  

[Testament]

the bottle is a volume and has a mass of gas in it under pressure

 

as you let it out the gas inside still takes up the same volume even though there is less mass of gas left in the bottle so the pressure is lower

 

same thing goes in the hose and with the flow

 

but simply the pressure downstream of the regulator will be proprotional to flow just not linearly, i.e. 20psi does not equal twice as much flow as 10psi.

 

it is also likely the calibrations on different flow meters and pressure gauges could be off.

 

 

the simple answer is set the thing where you think it should be, then keep turning the gas down until it effects your welding (on a test piece of course)

 

also note changing torch size and gas lens/cup sizes etc. will effect the amount of gas used - you might be able to see that on the flow meter if you leave the regulator set at the same pressure and change one thing at a time.

[Bangbug]

Its why you have a flow METER and a pressure REGULATOR.
It's a non-linear relationship Pressure vs Flow.
Essentially you could have 100psi "flowing" the nearly the same amount (you can, but through the same aperture is what I speak of) as 50 psi.

With welding (I imagine) you need to have different flow rates at pretty much the same psi for different size cups.
The psi is there to move it out of the cup, expand in/around the cup and form your shield. (it's pushing against the expansion and gas and shit caused by the welding)
The flow will give it the size of the shield (volume your working on).
Bigger cup, more shield so more flow but psi (probably) the same as the welding is still the same process at the tip.

I don't weld, would really like to.
So I'm just making you read this for no reason and seeing how it stacks up mwahahahaha

Sheepers, listen to Sheepers, manners often not, panelbeating/painting/welding wisdom very often. Must think I'm a fanboy with all the likes.

 

Oh and your welds are looking good to this noobertus

[eke_zetec_RWD]

Check it with a flow tester at the cup. Some regs are not accurate from new

[eke_zetec_RWD]

After you have tested the setup for leaks. Simply just open the bottle with everything hooked up. Note the bottle pressure. Then shut bottle valve and watch the pressure gauge, it should hold pressure for at least a few hours. If not you have a leak somewhere

[EURON8]

Yup checked for leaks. It's good.

[sr1600]

I linish my tungstens to a point, they soon ball when your welding,

I find Most ali is clean enough to just weld without cleaning up, scotch brite is excellent to clean alloy

When you find settings that work, make a note of them, even better find someone with the same machine and pinch their settings

My tig is digital, fuck knows what each setting is, i just know what numbers should be in each box

Fancy putting up the numbers out of your old box machine? Or coming round mine for a few pointers?