Well I finally attempted some aluminum welding... had some sucess, definitely will take a lot of practice to get that steady hand... I have a few questions... first, setup;

Miller Syncro 200
ebay 16ga IC piping and some 1/8 sheet
3/32 gas lens, #6 cup
also tried 1/16 gas lens, #6 cup
2% thoriated red tungsten
3/32 4043 filler (also used a bit of 1/16 5356 not shown)
100a for piping, 120a for the alum sheet
18cfh argon
balance 3.0
tried with and without pulser at 2.0 and 7.0 (2.0 on the top 2 beads of tubing, 7.0 on the flat)

I had a lot of trouble keeping my beads straight on the tubing... do most people use some type of jig for a guide? Besides not being able to keep it straight, I found it quite tough to keep the torch and filler at the proper angle as I moved along...I could make it about an inch before I would have to stop and reset, or I'd be all over the place (which the pics obviously show). After a lot more practice...how long a bead should I be running on tubing...as far as possible?

Anyone see something glaringly wrong with my first attempts? I am thinking I need to turn my balance way up (more penetration) as I just read the white/cleaning area should only extend 2 or 3 mm outside the bead, correct?

2 things I noticed is that a lot of welds (but not all) looked dull or 'dirty'... when I used the 5356 filler most of the welds looked a lot nicer, quite shiny and clean. Also I had a hard time getting a nice start to the weld...the start always ends up being a flat wide pool.

BTW..the tubing was small sections cut off, so I was welding them together, not simply laying beads on top...

thanks guys
Matt


Modified by mkehler at 5:47 PM 4/23/2008

 

For your first try you didn't do that bad. I've seen much much worse on aluminum.
i'd switch to a pure tungsten, I normally set the balance right in the middle, i think around 4. I run a syncrowave 300, with no pulse.. Personally i think 3/32 filler is ideal for what you're doing.. how heavy is the tube you're welding?? A weld positioner will help you a lot with welding tubes together, but they're pretty expensive.. If you're not that serious about it you can just roll the pipe on the table, keep the heat low enough that your puddle doesn't roll or burn through, yet hot enough that it burns the dirt out of the metal. Play around with it on some scrap you'll get it.

 

welding around tubes is quite tricky when you start out. its all about practice. eventually you can weld about 1/4 to 1/3 of the tube around up to half depending on how the tube is held down.
also from your weld on the plate, it looks like you want to start off a little hotter and cool off a tad after you move a bit. you want to pay attention to how wide the puddle is and try to keep it constant. i know its easier said than done. and only time and experience will give you the ablility.
the 5356 appears shinier i think it was because of the lower silicon content? i remember reading it on the miller forum.
but over all looks good! much better then when i started.

 

Thanks guys... on that flat, you mentioned started a bit hotter..I was doing the opposite..slowly building up heat until a puddle started to form, then continuing. I'll do what you suggested and start hotter and cool off and see what happens. I have a pure tungsten lying around so I will try that as well.

thanks
Matt

 

Try messing with the balance a little i usually have it set at 6-7 on butt welds and depending on thickness. lay into it hard from the start to get the puddle going then taper back a bit once it forms. Im sure you have heard this but as you weld watch the width of the puddle to tell you if you need more or less heat, the key is keeping it uniform. And at the end of the bead try to taper back and before you loose the puddle completely make a quick dab of filler to keep it from having a big hole at the end.

 

Well I've been practicing a bit, getting better. What should the backside of an aluminum butt weld look like? Can someone post a pic of the inside of some IC tubing that shows what a good or adequate aluminum weld is? I either have a line all the way through, or when it DOES penetrate fully, it pretty much is falling through the tubing, I can't seem to get anything in the middle. Any inside pics of IC tubing appreciated.

thanks guys
Matt

 

forget the tubing/piping for now. Get a straight line on flat down first then you can move to the round stuff.

 

Sorry I am mostly practicing on flat..figured I'd ask for a pic of tubing because thats what I am practicing for...I'm not sure if that makes sense but anyways, I'll rephrase that to what SHOULD the back of an aluminum butt weld look like? Tubing or flat or..

thanks
Matt


Modified by mkehler at 10:19 PM 6/27/2008

 

ttt, anyone have a pic of the backside of a (proper) aluminum butt weld?