i cant seem to get a stable arc started when i try to weld aluminum. im a beginner so im not trying to weld anything together, im just try to get a bead down on a flat piece of aluminum.

the arc im geting is wild..it jumps all over the place, its not stable at all. i tried everything. lowering my amp or raising it doesnt do anything. my tungsen is of the orange band, and i ground it down to a ball at the tip.

all its doing is burning the surface...black all around it..and its creating craters. tried to add some filler rod but all it does is make the filler ball up.

 

Are you using AC to weld it? What kind of machine are you using?

 

its a syncro 180 and yes its set on ac

 

i set my syncro 180 to about 100 when i do 1/8" aluminum. are you sure its clean? i tried welding some the first time and it wasnt clean so it kept jumping around

 

yes i cleaned the surface and the filler.

im not trying to do any penetration passes..im just trying to get a bead down on the surface.

 

bump for a good question.

 

What electrode are you using? What shape of a tip are you trying to weld with?

 

2% cerium, 3/32"

and the tip is rounded out.

local supply store is closed on weekend so i cant get anything else

 

Might be a stupid question, but your gas is on, right?

For aluminum I use either 2% zirconiated or pure tungsten. You might want to try one of those.

 

yes gas is on...but im not sure if its 100% argon or not....it from an old tank that came with an old mig welder...and its says argon on the tank.

well local supply store doesnt carry zirconiated tungsten..so ill have to order online.

do you think that the cerium tugsten is causing the problem?

 

It's possible but I'm unfamiliar with that type of tungsten and if it works well with aluminum. I'd suspect the gas first though, especially now since you said it was used with a mig welder before. It's probably mixed argon.

 

so aluminum is supposed to be used with 100% argon?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ineedhelp &raquo;</TD></TR><TR><TD CLASS="quote">so aluminum is supposed to be used with 100% argon?

</TD></TR></TABLE>

Oh yes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Goullish &raquo;</TD></TR><TR><TD CLASS="quote">

Oh yes.</TD></TR></TABLE>
100% argon
3/32 tungsten, although you could get away with 2% thoriated
try a gas lens with a #7 cup

 

You can also use an argon/helium mix. The tungsten type will make very little difference.

AC welding is inherently unstable, but is greatly improved withe the newer inverter machines.

YOu mentioned that it's unstable when starting. SOmetimes, just because it's such a low amperage, stability is a worse problem at startups. Try just giving it some more pedal at startups, even if you have to back off a little bit at the piece warms up.

 

usually how much amp is needed to weld aluminum.

 

90amps works well for ~1/8" - I just started, but I've found that flooring the pedal, then backing off halfway and getting the tungsten ~1/8 - 1/4" from the surface, all at the same time really helps alot

 

Does a syncro 180 have high frequency?

 

well i finally got to weld aluminum today. thanks to everyone that helped me get started.

after practicing for a few hours...here what i managed to do by the end of the day. please critique...any advice would be appreciated.



cant seem to get these dimple to go away..even if i ease off the pedal.


here are some passes where i restarted on the existing beads.


here is the underside of the tube.


the tube is 6061 t6 and about 1/16" thick. i didnt burn through these but it makes the lumps on the underside of the tube. how do i get rid of them.

later i tried to weld two ends together...and it was a mess...couldnt get a puddle started without burning through the tubes.

any suggestion on theses? help me out guys.

 

the lumps on the underside is from too much heat. back off the heat just a little bit until it is just scorched a little without lumps on it

 

if i do let off on the heat..the beads become thicker/taller. i guess ill just have to learn how to wled faster.

any advice on when i try to weld the ends together?

 

I've been using a synchrowave 250 at school and noticed that messing with the **** that varies between cleaning and penetration helped - don't know if yours has the same **** (don't know much really)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bjorn &raquo;</TD></TR><TR><TD CLASS="quote">I've been using a synchrowave 250 at school and noticed that messing with the **** that varies between cleaning and penetration helped - don't know if yours has the same **** (don't know much really)</TD></TR></TABLE>

Yes, it has that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bjorn &raquo;</TD></TR><TR><TD CLASS="quote">90amps works well for ~1/8" - I just started, but I've found that flooring the pedal, then backing off halfway and getting the tungsten ~1/8 - 1/4" from the surface, all at the same time really helps alot</TD></TR></TABLE>
This is because aluminum will soak up the heat...basically pulling heat from the puddle till it gets the surrounding area warmed up. This heat soaking can be countered by additional heat early on...then backing off as the plate warms up.
I like about 1/8" gap usually, but in most cases 1/4" is fine also. The arc gap on AC doesn't have to be really tight.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MrMacros &raquo;</TD></TR><TR><TD CLASS="quote">Does a syncro 180 have high frequency?</TD></TR></TABLE>
Yes. The Dynasty, Syncrowaves, Econotig, and Maxstar's all have HF.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ineedhelp &raquo;</TD></TR><TR><TD CLASS="quote">cant seem to get these dimple to go away..even if i ease off the pedal.</TD></TR></TABLE>
You just have to back off of it even slower. Some machines will not reduce power down very low when tapering off. For example, some older machines may not go down below about 20 amps, and when they get that low, they just shut off. If this is the problem, try letting it cool for a few seconds, then remelt the crater and taper off again, maybe even pumping the pedal a bit at the end.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MrMacros &raquo;</TD></TR><TR><TD CLASS="quote">here are some passes where i restarted on the existing beads.</TD></TR></TABLE>
Not bad at all on the starts and stops.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MrMacros &raquo;</TD></TR><TR><TD CLASS="quote">here is the underside of the tube.</TD></TR></TABLE>
Not bad. Granted, you are best if nothing pushes in, but that small amount won't really be a problem.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ineedhelp &raquo;</TD></TR><TR><TD CLASS="quote">if i do let off on the heat..the beads become thicker/taller</TD></TR></TABLE>
Add less filler then.


http://www.imagestation.com/picture/...6.jpg[/img]

the tube is 6061 t6 and about 1/16" thick. i didnt burn through these but it makes the lumps on the underside of the tube. how do i get rid of them.

later i tried to weld two ends together...and it was a mess...couldnt get a puddle started without burning through the tubes.

any suggestion on theses? help me out guys.[/QUOTE]

 

thanks for the advice guys.

i tried welding the ends together again tonight. had a little more sucess, but the main problem is i have a hard time getting a puddle and the first bead started without burning through. when i do get a bead down..the underside is bulky and ugly. after the inital bead i can lay the rest down ok.

any tips on how to get a nice puddle for the first bead, without burning through?

how do you guys start it? amp? what size tungsten?

again this is on 1/16" thick aluminum.