Figured I would ask here since this is what the forum is for.

My brother is my fab guy and he is having some issues with aluminum.Hes now wanting to try helium mix instead of 100% argon.

Basically if he does a bead on a flat piece its good.Once were talking like an actual connection of 2 pieces it will "pop" here and there.Hes says either the machine is going thru its whole duty cycle trying to do a longer bead -or- its just the breaker turning off when the fan on the machine is about to kick in.Machine is a Miller syncrowave 200.

Right now hes already...
-cleaning with stainless wire wheel on both sides
-wiping with acetone including the filler rod
-machine set to 85 amps to weld .120 thick sheet aluminum
-using green tungsten w/small cup

Picture is a crappy phone pic but you can kinda see it starts off good on the right but then in the middle it just pops all over.



Any help is appreciated,thanks.

-Alex

 

maybe your brother should post because I dont understand the 85 volts for .120 do you mean 85 amps?

 

looks to me like he has touched the tunston down which for me tells me im not hot enough, or i had to much to drink the night before..LOL p/s any time you touch the filler or the peice your welding snap of the electrode and re-ball the end then continue or your arc will be all over the place.

 

^^^ That's what I was going to say. It looks like the welds are cold and he dipped the tungsten in the puddle. I have done it plenty of times to know how it looks. LOL

Stefan

 

tell him to turn up the amps and stop dabbing! once you dab once with aluminum your done until you clean the tungsten and the work. he clearly made love to the puddle with his tungsten there and kept going to town. its not the machine, its the user

 

Ah yes thats what I meant 85 amps.

The .120 is the thickness of the aluminum sheet,about 10 gauge equivalent.

So is 100% argon the right choice for this? I'll show him the above info and see how things turn out.Thanks guys.

 

Everything I've ever read about pure tungsten says to not use it because there are much better options out there, starting with 2% thoriated, but then again I do have an inverter machine.

Also, like everyone else said, 85amps seems really low.

100% argon works fine. What's his flow at and how big of a cup? the helium mix just allows you to use less amperage to weld.

 

Power is cheap, helium is not

 

User error.

 

Also what tungsten diameter? if he's using a very small diameter tungsten it will overheat and pop. at least 1.6mm if not 2.4mm

 

Lee> good call, 1.6mm pure is essentially worthless for anything

 

Flow says 10 on gauge when its on the red and 20 when its on the black.Hes right in the middle.

Cup is #10 with gas lens

 

When we welded aluminum in school we were using 2% thoriated tungsten (red) dunno if thats part of his problem, i'm still a welding rookie too. But, that seemed to work for me

 

for welding aluminum i dont use a gas lens i usually use a size 4 or 5 cup
and for something that thick id run about 120 amps and just adjust throttle accordingly

 

Hadn't really practiced hands on since we been busy doing other stuff but had been reading here and there.

This is a pic from yesterday.The last time my bro had welded aluminum was when i posted this thread.The only difference now is he balled the tungsten smaller.



The left is with more heat,the right is with less.Didn't clean it with wire wheel or acetone at all.Will try that later when there is more time.

 

Right side looks better. Weld should be shiny

 

bump it to 130-140 amps

use red tungsten sharpened to a point, dont bother putting a ball on it

 

These 2 pics are using red tungsten with no ball

EDIT:
Forgot to say this is 24 gauge

 

Looking good. Normally on my syncrowave when I'm welding 1/8 aluminum I'll set the it to about 125 and control the puddle as I ad filler.if that makes any sense.

 

not bad, ripple could be a bit tighter but still not bad. what size filler?

 

Filler rod is 3/32

Will actually practice when there is time.Thanks for the tips guys.

 

your doing a lot better than not bad. good job!

 

try with 1/16 filler

 

Thanks.

Will scoop some up next time at the welding supply.

Oh yeah those welds are still with NOT using a stainless wire wheel or acetone either.lol.

 

lol