TIG Welding Aluminum Joint problem

admin

First time posting here.I've started to get interested in TIG welding aluminum and am finding it challenging trying to connect two square tube pieces.  A lot of times the aluminum starts retreating from the edge and everything turns to crap.  It seems hard to get a weld pool started on two pieces before I start adding filler.  Out of the 20 times I tried, only 3 joins didn't totally collapse... and one of those the weld didn't penetrate into the base.I am brushing the outside of all four corners in one direction with brush and along the edges.  I can't seem to get inside the 1" square tube and feel the trash is being sucked out.  Is that what could be happening?   I uploaded pics.

Attached Images



Reply:Are you using 100% Argon and AC, are you using a foot pedal.  You need to hit it hot and quickly back off on the heat when it first starts the puddle.  watch some YouTube videos on aluminum welding to see how they start the welding process.  Try welding the middle of a flat plate aluminum no filler to see how it looks then add filler to see how that goes.DIY CNC Plasma table USB BOB Price THCHypertherm 65Everlast PowerTig 255 EXTMiler 180 Mig13" metal latheMill/ DrillECT, ECT,
Reply:To me it seems like you are adding the filler way too soon and you are creating that mess.  You need to let the AC break up the aluminum oxide until you get a shiny puddle THEN add filler wire.
Reply:

Originally Posted by acourtjester

Are you using 100% Argon and AC, are you using a foot pedal. You need to hit it hot and quickly back off on the heat when it first starts the puddle. watch some YouTube videos on aluminum welding to see how they start the welding process. Try welding the middle of a flat plate aluminum no filler to see how it looks then add filler to see how that goes.
Reply:

Originally Posted by Weld_

To me it seems like you are adding the filler way too soon and you are creating that mess. You need to let the AC break up the aluminum oxide until you get a shiny puddle THEN add filler wire.
Reply:You are getting oxygen in your gas flow. Somehow it is swirling back and sucking oxygen back in. Looks like a gas coverage issue to me.www.tjsperformance.comDynasty 300 DXHTP 240HTP Microcut 380Hyperthem 85JD2 Hyd Bender and HF Hyd Ring Roller all in one =(Frankenbender)Bpt. Mill/DRO4' x 8' CNC Plasma TableInstagram: tjsperformanceYT: TJS Welding and Fabrication
Reply:Have you tried to pad some beads on flat part of the tube ? What kind of tube is it, 6061 or something you got at home depot ? I have been given angle, and tubing of unknown composition that has welded lousy, almost like it was anodized. Try welding a piece of the tube to the bar. good luckAirco 250 ac/dc Heliwelder Square waveMiller Synchrowave 180 sdMiller Econo Twin HFLincoln 210 MPDayton 225 ac/dcVictor torchesSnap-On YA-212Lotos Cut60DPrimeweld 225 ac/dcPrimeweld mig180Miller AEAD-200
Reply:You will get this if you are closing the tube - other end already welded. The air inside gets hot and as it escapes due to pressure it will ruin your joint. I’m not a professional, so take this for what it’s worth. When I have a closed tube I will leave part of the joint unwelded, open for air pressure. After it has cooled, I go back and quickly close the joint. It looks like you are soaking the part with heat. As CourtJester said, hit it with lots of heat to get puddle going, then quickly back off the pedal and use filler. You have to move fast on aluminum joints or it melts away. Your flat bar shows you have the concept, just need more practice to be consistent.Burt _____________________Miller Syncrowave 250Millermatic 211Miller 375 Plasma Cutter Hobart Handler 120www.10FtDrillBit.comwww.MyWelds.com - pictures of my work
Reply:when you brush the material, do you use a stainless steel brush, one direction and brush it till you feel the brush drag.  It looks to me that you are not removing the oxidation layer.  You are trying to solidify the oxidation which takes lots more heat than the actual material.  Focus on a more solid edge of the material (about 2 dabs) then wash to the edge.  It WILL take practice.  good luck and have fun with it.
Reply:Thanks for all the replies.  I'll try the suggestions of going in strong at first, and checking gas flow.I'm cleaning it with a wire brush going only in one direction.  The square tube isn't from Home Depot... it's from Metal Supermarkets.