how do you start the weld with a stable arc. for me, most of the time, as soon as i hit the pedal it's inconsistant for a fraction of second, and sometimes allows contaminants to form, or lets some aluminum oxide form.
also, how do i keep the blueish purple "dust' from forming every once in awhile.

my welds are good in my opinion, but whenever this happens i get frustrated, and im always looking to improve.

thanks


Modified by dfoxengr at 2:42 PM 3/23/2007

 

How thick of material?

 

most stuff i do is between 1/8 and 1/4

but this can happen on any width

 

If you're getting that blueish soot, it's because you're burning aluminum off the tungsten.

It is normal for the arc to be unstable for a little bit.

Make sure your tungsten is 100% clean. If you accidentally dip the tungsten into the molten aluminum, you have to stop and grind the contaminated part off of the tungsten.

Good luck!

 

yeah i try to keep it as clean as possible
thanks.

 

Keep it clean...

Aluminum is VERY important that you keep it clean.

The tungsten has to be VERY VERY CLEAN.

grind/sand the aluminum prior to welding and use more heat than you think is necessary.

 

yeah i do all those.

like i said, my welds are pretty good, i just hate the start up.

 

AC is not going to be stable. AC is a very irratic arc but will become somewhat stable after the initial start up. If you don't have an inverter machine that just get used to it. This will not effect anything.

You shouldn't be picking up any contaminates unless you are scratch or lift arc starting. Do you have a remote like foot pedal, button, finger switch?

What do you hate about the start up? I don't understand why it should matter.

Sounds like the blueish color is your tungsten contamination. The aluminum sounds like it is a little dirty. The material can be a little dirty because the AC arc will clean it to an extent.

If you contaminate the tungsten by dipping into the puddle than I wouldn't worry too much about. AC is pretty forgiving when it comes to cantamination compared to DC. If you contaminate it then just keep welding it will clean up on its own. This is not ideal but it is fine for a begginer and something that is not critical for contamination.

Be careful when talking about color under the welding helmet. I have many different helmets and they do not share the same darkening colors. Some arcs look like blue, green, red, orange, yellow.

 

nobody was talking about color from under the helmet.

its a syncro 250, and my personal is a syncro 200, so both have remote.
our lab is getting a dynasty 200 this week, so ill be able to try out an inverter as well.

thanks for the advice.

 

I have no idea what you mean by blueish or purple dust. It's been almost a year since I've welded AL though.

I would suggest NOT sanding the basemetal as the little pieces of the grinding/sanding disc can get left behind.

 

i dont sand it.
stainless brush only.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dfoxengr &raquo;</TD></TR><TR><TD CLASS="quote">nobody was talking about color from under the helmet.
</TD></TR></TABLE>

Well I guess I misunderstood. I don't know how else you would see the blueish color if you don't see it under a helmet.

If you use a type of sanding disk try a red scotch brite pad and some alcohol.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dfoxengr &raquo;</TD></TR><TR><TD CLASS="quote">i dont sand it.
stainless brush only.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dfoxengr &raquo;</TD></TR><TR><TD CLASS="quote">also, how do i keep the blueish purple "dust' from forming every once in awhile</TD></TR></TABLE>

i dont see whats to misunderstand.

 

its not a big deal at all but "Agtronic" had mentioned about the blueish soot. I jsut assumed he ment while welding it looks blueish.

 

acetone would be your best friend, happen to me, now i love it.

 

yeah i sometimes use it, but not as much as i should. too lazy. thanks everyone.