Hi Everyone,
I am fairly new to welding. I played around with a oxy-acetylene
rig for about a year and then made the big jump to TIG. I am having
a blast with it and am glad to get rid of the task of cleaning ugly slag
and general crud off of welds :)
I have a project where I need to join fairly thin (3/32) steel rod together.
One piece is just laying on top of the other (at 90 deg) so there is no butt
joints. I guess it's more of a fillet. I am using a Lincoln Precision TIG 185 and according to the handy-dandy super-secret decoder ring supplied with the unit, I am
supposed to be using 1/16" electrode, 3/8" cup orifice, 1/16" filler rod,
and 95 amps of juice. Obviously the amperage is way too high for
small steel rod like that so I have been playing around at 20 amps.
I am using a 3/32" ceriated electrode which is a little too thick but not
that far off. I also have the pulser set to about 1/2 of it's max but I am
not sure what exactly that value would be. I have tried the both with and
without cleaning the joint first. I have also tried it without the pulser
with no luck.
The problem I am having is that I can only get the tip so close to the
v-groove between the 2 pieces but not inside. When I am welding, a
pool forms on each piece but they are too far apart to join together.
I keep adding juice for a longer time and eventually one or both pieces
just melts off. Also, the arc bounces back and forth between each of
the 2 pieces and does not just stay centered in the middle. I tried
using .045 filler rod which merged the pools but still ended up melting
off one of the pieces. I would like to get the tip farther in so that the
pool forms right at the point where the 2 pieces touch but if I get in
too close I always end up touching the tip to one of the pieces which,
of course, is disastrous :)
Does anyone have any suggestions on how to approach this??
Any help would be greatly appreciated!!
Victor
You will get lots of good tips on this one.
Here are a couple.
1/16 or 0.040 electrodes will work better.
Your amps are ok as long as you have a foot pedal.
Tungsten tip prep; It is a common misconception that a long slim taper on the end of your tungsten will provide more directional control, Not so. Make the angle a bit more radical and leave the smallest blunting at the end you can achieve, this will help with getting that arc placement you want.
Next. Clamp your rods to a piece of flat copper sheet or bar for a heat sink.
I'm not a big pulser fan but the book says you will get better arc directional performance with a higher pulsation rate.
Maybe most important. Surface prep of the rods your welding together. Cleaning right before welding (all rust and scale, to bright metal) will lower the amperage requirement, thus giving you more control.
That ought to get you started
I hope you didn't get rid of the O-A set. This is a good project for the application of brazing or even lower temp silver brazing over welding. Such small items will come up to temp almost instantly with even a small tip. And, since the temp is much lower than for welding you're much less likely to melt the pieces that you're trying to join.
Dave
Try a larger filler 1/16 or even 3/32, lay the wire between the pieces and start the arc on the filler. Hit the pedal hard as if trying to make the weld fast and back off fast. This will put most of the heat in the filler and not the other pieces.
Also if there are hundreds of pieces consider a spot welder, they do a nice job on tee joints of this design- Ted.
Thanks to everyone for the advice. I give your suggestions
and try and will report back. I did keep my O-A setup
since I still use it for cutting and bending. I was not able
to try things out this weekend since my garage is all
torn up while I rebuilt my workbench.
Thanks Again,
Victor
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