Re: TIG Welding Problems
 

"Brand new"? Then call Miller. They are known to have good tech support. It could be a pinched line, bad connection to the gas solenoid due to shipping shakeup, etc.

Re: TIG Welding Problems
 

Yes, brand new. The welder has been set up for less than a month, and still hasen;t successfully laid a bead in TIG mode. The arc welder works just fine.

Re: TIG Welding Problems
 

The welder is fixed... It turned out to be a clogger gas soleniod, just as I had suspected... Now I need to relearn the settings. Thanks for all the advice, especially thos who to the time to PM me such exhaustive explainations. It really helped. You guys are great!:D

Re: TIG Welding Problems
 

One quick way I've seen to put a Clean Ball on the Tip of your electrode is to grind the electrode to a "blunt pencil" point and use a copper Plate about a 1/4" thick as your first target. This is less likely to contaminate your electrode than your actual aluminum work piece. Also you should grind your electrode axially (along its length) not radially across its diameter. This produces a more directed first strike and allows you to better control the ball formation.

Re: TIG Welding Problems
 

Thank you for the tips. I have benn grinding the tip axially, I just didn't know about the copper plate thing. :D

Re: TIG Welding Problems
 

To weld aluminum, use AC for the actual welding and DC positive
prepare the electrode. Use a pure tungsten (green) electrode.

You use DC positive to prepare the electrode because
you want to melt it a little without forming a puddle.
You always use a separate thick plate for this and
a 1/4 thick (or thicker) aluminum plate will work fine.
Copper is better, but I have never had access to one.

To prepare (ball) the electrode, grind it flat on the end, and then
debur just enough to remove any flash left from the grinding.
Debur it at about 45 degrees, but just enough to remove any
flash. The basic geometry of the ground electrode should
still be flat on the end. To ball (really hemisphere) the electrode,
set the welder to DC positive and then light an arc on a thick
aluminum plate placed so that it is level and the torch is pointed
straight down. Use about 1/8 inch clearance
between the electrode and the plate, or just a little closer. Crutch
your hand to avoid contact between the electrode and the plate.
Watch the end of the electrode carefully as you do this and
you will see the edges melt and the hemisphere end form. Your
goal is to get a hemisphere on the end of the electrode without
having a "ball" form that has a larger diameter than the electrode
itself. You have to be careful with the heat as it is easy to overheat
the electrode with DC positive. With experience, you will notice
that you get a little extra flare of light when the heat it just enough
to melt the end of the electrode and you will start judging things by
watching for this flare as you increase the heat. Once the heat is
right the end of the electrode melts and develops the right shape
in just a couple of seconds.

Since you need to make adjustments to the welder to prepare
electrodes, and electrodes come in packages of 10, it pays to
prepare them all so you can just change out electrodes
without having to switch setups when you contaminate one.

You will be turning the current down when preparing
electrodes as DC positive puts a lot of heat on the electrode,
and then turning the heat back up for AC welding of aluminum.
Don't forget to turn the welder off before changing polarity.


Have fun,
Eugene

Re: TIG Welding Problems
 

One possible source for "scrap" copper plate is the offcuts of bussbars in high current industrial electrical installations. try to find an industrial electrical contractor and the might be able to donate a piece or at least let you buy it at scrap pricing $3-4.00 per pound. A 3X3" piece is what we've used at several fabricators I've worked at.