i dont tig aluminum very often but noticed unlike steel, the filler tries to run from the arc, almost like its magnetically opposed to the arc or like a breeze is blowing it away. steel seems to want to jump right in.

im guessing its the polarity alternations in the torch but really have never heard the issue addressed. do you guys experience this or have any cure? wonder what grounding the filler would do.. ?

if it matters, my machine is a semi-functional (ancient) linde UCC-305, set on AC. gas flow doesnt change it. the unit only has high freq and AC stabilizer for settings.

 

The filler is not part of the weld circuit so it shouldn't be charged until it touches the weld puddle. Since you said you don't tig aluminum a whole lot, I'm guessing that your rod has been sitting around for a while. There's probably an oxide buildup on the rod, use stainless wire and acetone to clean the rods.

 

The key is that you have to keep your heat focused on the puddle, not the wire you're adding in. Keep your puddle a consistent shape, and let the addition of wire change only the height of it. When welding, you have to remember that you're welding the base material, not melting filler on top of it.

When welding AC, the arc is usually wider. This means that the filler metal hits heat much faster as you move towards the puddle. For AC welding, try to keep the tungsten at about a 75 degree angle, just enough angle to see up under the cup well. If you angle too much, the heat is like a rock skipping across water...it just heads right for your filler metal.

 

thanks guys, both great answers.

yes, the filler has been sitting but i did acetone scrub the hell out of it. none the less, the filler is introducing a slaggy black contamination to the puddle. i guess i need to sandpaper then acetone. it wasnt a critical application so i continued.


me personally, with steel i tend to just lay to filler on the part and let the puddle walk over it. i seldom withdraw the rod. looks like aluminum really needs to be dabbed in and out drastically. as you imply engloid, any time the torch even slightly canted toward the filler (round part, so often) it just mushed and blew away. this never happened to me on flats.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike_belben@yahoo.com &raquo;</TD></TR><TR><TD CLASS="quote">me personally, with steel i tend to just lay to filler on the part and let the puddle walk over it. i seldom withdraw the rod.</TD></TR></TABLE>

You need to dab the filler with any metal otherwise you will get incomplete fusion at the bottom of the weld (arc needs to melt the base metal before melting the filler, otherwise the base metal won't melt).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike_belben@yahoo.com &raquo;</TD></TR><TR><TD CLASS="quote">me personally, with steel i tend to just lay to filler on the part and let the puddle walk over it. i seldom withdraw the rod. looks like aluminum really needs to be dabbed in and out drastically.</TD></TR></TABLE>
You can do this on steel (DC), but it is much harder on aluminum because the arc is much wider. This means you usually have to either feed the filler in fast, or dab it in.

Although many think that laying filler down and running over it will cause fusion problems, it's like any other method...it can be done right and it can be done wrong. Many of the old time "freehanders" used to argue this about walking the cup, as typically when walking the cup, you leave filler in the puddle. I think they just wanted to argue that their weld was better than that of a guy that walked the cup. Clearly, cup walking is one of the prettiest methods. In time, these guys have had to admit that it can be done...cause this method has passed millions of xrays and other types of tests.

If you're to cold, yes, there will be fusion problems. If the puddle is melting smoothly, this likely won't be an issue.

With aluminum, it doesn't change colors as it heats up. You just have to get a nice shiny puddle prior to adding wire. Aluminum will get a mirror shine when it melts, and without that, you can't dab in wire.

 

(as stated above) In lay: your holding your filler too close to the arc, its getting too hot resulting in it turning into a peice of aluminum spaghetti before you can dip it into the puddle

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by legendboy &raquo;</TD></TR><TR><TD CLASS="quote">(as stated above) In lay: your holding your filler too close to the arc, its getting too hot resulting in it turning into a peice of aluminum spaghetti before you can dip it into the puddle </TD></TR></TABLE>

Good point...a little bit different from what we stated above...but I wanted to add a bit now that you brought this to mind.

When you pull the wire out of the puddle, pull it about an inch away, not just barely out. This lets your wire cool. This will usually result in more defined ripples in the weld, and means you have a little more time to get the wire to the puddle before it melts.

 

i get what was said about the fusion problems but i dont think its the case with me. my welder is broken- must control heat at the panel rather than pedal and its outside in an unheated garage so im talkin about a 10 degree or less part being welded here. i start with the heat way up. when the part saturates i just start haulin *** and feeding wire. undercut is more a risk for me than lack of penetration.

**disclaimer** wrong way to weld. sometimes gotta make due with what ya got, and this is what i got. no justification for a new machine currently. i dont sell parts to the public so no need to flame me on what i already know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike_belben@yahoo.com &raquo;</TD></TR><TR><TD CLASS="quote">**disclaimer** wrong way to weld. sometimes gotta make due with what ya got, and this is what i got. no justification for a new machine currently. i dont sell parts to the public so no need to flame me on what i already know.</TD></TR></TABLE>
They didn't always have foot pedals and high frequency. In fact, I never worked a construction job that had either one.

 

thats exactly how i feel about it. skyscrapers, bridges, ships, pipelines, railroads, mines, foundries, etc are still in service from long before welders had bells or whistles.

 

I think it's a lot more simple than you think. If the filler is melting before you have a chance to dip it, it means your puddle is not hot enough, in most cases.

 

the filler was melting before i could get it NEAR the puddle.

arc was very hot, too much heat going into my filler. removing filler more deliberately was the remedy. problem solved.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike_belben@yahoo.com &raquo;</TD></TR><TR><TD CLASS="quote">the filler was melting before i could get it NEAR the puddle.

arc was very hot, too much heat going into my filler. removing filler more deliberately was the remedy. problem solved. </TD></TR></TABLE>



you may also want to increasing your travel time (if u can!)

 

It can also be affected by the length of your arc. With the arc being like a fan, the farther you are away from the metal, the wider it is by the time it gets to the metal.

I typically keep an arc gap of about 3/16" with aluminum. You don't have to hold tunsten very close with AC work. Many people will tell you that the key to all tig work is keeping the tungten close as you can, but that's not true. Even with DC work on carbon and stainless, I will usually have a gap of about 1/16-1/8" and it works fine. If you have good control, go with 1/16", if not, you're better to hold 1/8" than to dip the tungsten all the time.

Glad you got it straightened out. Where's the pics???!!!

 

i dont have a digital camera. my brothers was here a lot more often but he bought a house so i have less acess to it. besides, welding is the least flattering thing i do, so there are better pics to *****.