First aluminum welds

[BB69]

I finally got some pics of my first aluminum welds. These welds were made in the TIG welding class I am taking. They are from the first day of welding. We started welding 1/8" thick aluminum coupons together with a simple butt weld. The instructor had us position the coupons so there was about a 3/32" gap between them we had to fill. I was amazed at how much filler is needed for this. I am struggling to get enough filler put into the weld. As a result, I am not getting as much build up on the top of the weld as I want. However, I got enough build up, along with full penetration for the instructor to have me move onto lap welds. That's where I will pick back up this weekend.

Caution, these pics are large so you can see the detail.

Lap weld
http://home.comcast.net/~grulich69/w...D-2625925.html

Butt weld
http://home.comcast.net/~grulich69/w...D-2625921.html

I have a lot of practice time ahead, but I am enjoying it.

Ken



EDIT: I finally figured out how to add thumbnails. These are much smaller than the pics in the links.

[Matt@RFR]

See attached picture.

What I've circled is REALLY REALLY bad. It's either cold lapping or the material/puddle rejecting filler metal. Either way, there's no fusion there, and it's just begging to tear.

Remember, the heat goes where you point the tungsten. Lap welds suck on aluminum, but you HAVE to get heat into the base piece.

[BB69]

Thanks for the advice Matt. Those were some of the same areas the instructor pointed out. Like I said, I haven't passed this objective yet. I only had a little bit of time to work on lap welds. I will get started back on those first thing tomorrow morning. The hardest part for me so far is being able to feed in the filler without stopping to regrip it. Any suggestions for that? I have seen people that advance it with their thumb and finger, but I haven't been able to do that yet.

Ken

[Matt@RFR]

It really sounds like you need to use much bigger filler. You should be able to a 6" weld without repositioning the filler in your hand no problem.

On an 1/8" lap, I would expect to use 3/32" filler.

[BB69]

I was using 3/32 filler for everything. I had the output set at 140 amps, and the AC balance set slightly more to the penetration side. I was also using a 3/32 tungsten as well. I was getting good penetration, and the width of the weld seemed good, but I could only go about 2" on the butt weld and about 3" on the lap. I held the filler rod so that there was maybe 8" exposed. The instructor held the filler rod much further back. I tried that, but I didn't feel like I had enough control over it. That will probably take more practice.

Ken

[Matt@RFR]

Is there any helium in the gas you're using, by any chance?

[SShep71]

Ken,
I know matt pretty much explained eveything you need to know. I just have 2 suggestions, I dont know what your using to clean the AL but I use scotchbrite pads, tear off a small piece and use it lightly. Try cleaning your filler with alcohol, and snip off the first 1/4 of the filler rod. Sometimes dirt can become embedded in the end of the rod.

[BB69]

Ken,
I know matt pretty much explained eveything you need to know. I just have 2 suggestions, I dont know what your using to clean the AL but I use scotchbrite pads, tear off a small piece and use it lightly. Try cleaning your filler with alcohol, and snip off the first 1/4 of the filler rod. Sometimes dirt can become embedded in the end of the rod.

Thanks for the tips. We use a stainless brush. The filler rods are just stored in a tube next to the welding stations. I don't know what they would allow for bringing in any alcohol, but I will talk about this with the instructor.

Ken

[SShep71]

I wouldnt recomend a stainless brush, It can actually push the "dirt" beneath the surface of the aluminum. Ive never had a problem like that, so I dont know if its completly true. I just dont wanna find out the hard way. Maybe matt can give a lil input on that, but I only use scotch brite. Clean the weld area with alcohol too.