by Charlie
(Oshkosh, WI, USA)
Any suggestions on getting into the really tight acute angles I run into on my aircraft fuselage?
All my welds are good where I can get access but I struggle in this area. It is often a "bridge weld" since I cannot get all the way down into the base of the angle. Sometime it will "bubble" and look terrible with porosity. Sometimes it will work fine. I try to keep the tungsten stick out to 1/2 inch and pre purge by tapping the foot pedal before sticking the arc.
Today I tried putting some aluminum foil on the backside to "catch argon", I tap the foot pedal to pre purge.
I'm running a gas lens with 1/16th tungsten, argon at 15CFH.
I wire brush everything so there is no mill scale. I've tried it with a standard cup #4 without any better results.
If you want to see the project, visit www.facebook.com/piratecub
Thanks for the help. Great website.
Charlie
-------------------------------------------------
CNI makes a #12 cup that lets you extend the electrode almost an inch
I use either scotchbrite diffuser or a fine wire screen for a diffuser.
you are also on the right track with the foil to trap gas...thats a very good idea.
you can see the cup here...