Im looking for some people with experience welding aluminum (4042) about 1/16" thick with a spool gun. (intercooler pipes)
It seems to work well with a very fast pace and some good heat but its difficult to get a good start without pooling up.

Im using a small 140C Lincoln with 100% Argon.

... And I know it would be better with a TIG, but Im working with what I have at the moment!

Thanks guys

 

Make sure you pull the trigger a little to start the shielding gas before the arc. Its just a matter of finding the setting thats work best for the postion and materials. I have only done thicker stuff with a spool gun but it can look really good if you practice. It usually helps to weave rather than running a staight bead. On a 1/16" butt weld it might be tough. I would go down hill and fast like you said.

 

Ive found finding the setting is really is key by switching to different aluminum (4043 or 5052, etc)

Also, I know what you mean with the gas. The welds seem to come out pretty clean though, no problems there.

I wish MIG had a pedal for voltage like a TIG! That would make starting out the weld a lot easier. Ive noticed it builds up too much at the start but when the heat finally comes, its a smooth weld from then on.

Hmm that tends to be the only problem now. Good tips though, I appreciate it.

 

as silly as it sounds on such thin material, what about preheating and turning the amps down? or maybe setting up a heat sink so you can start with lots of heat and not have it be too hot later in the weld?

 

Hmm, yes that could work.

Trying to weld 2.5" pipes is a little difficult. I either have to
1. run a 2-3" bead then rotate the pipe, or
2. try to rotate the pipe as I weld <--- not quite my favorite thing to do

Using a heat sink may be a difficult to set up seeing as the pipes are long and I dont think I could set up an internal heat sink. Externally it may get in the way.

Preheating - Im not sure if I can get it hot enough to start with. Any ideas for quick heat?


Modified by random_tuner at 7:04 PM 2/13/2008

 

you don't need it super hot to make a difference. there are heat blankets for welding and some for bending gray pvc conduit. I bet you can rent the conduit ones. they just wrap around the tube with velcro and would keep a foot on either side warm.

they also have this gel that you can use for a heat sink. I have never used it but I hear it work well in some applications.

but this all just sounds too complicated haha. weld it up and go drive!

 

Oxy-Acetylene torch?

 

if you can wire a foot pedal into a smiley then what's so hard about doing it for a mig????

 

haha a lot of spool guns have a dial on the bottom. I have been known to tweak that mid-weld with the other hand.

 

I never had a problem with not enough heat, but I've only used big 250A migs - maybe the 140 doesn't have the nuts to start off hot?

I usually run near the same amount of heat as I would with mild, but with much faster feed to keep it from burning through. I also push at ~70 degree angle on lap welds, and ~45 on T welds - that will give you nice sharp beads, just like with mild

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
but this all just sounds too complicated haha. weld it up and go drive!
</TD></TR></TABLE>

Thats what Im thinking, I know there has to be a technique Im just missing out on.... oh and what I wouldnt give to drive this car right now!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">if you can wire a foot pedal into a smiley then what's so hard about doing it for a mig????
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Very funny you say that, thats the first thing I thought of when I knew I needed to control the heat. Im sure it could be done.... hmm...


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">haha a lot of spool guns have a dial on the bottom. I have been known to tweak that mid-weld with the other hand. </TD></TR></TABLE>

Thats funny too cause I just tried tweaking the amps while I was starting a weld... scary thing is it works a little better! Hard to keep steady though thats for sure.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I never had a problem with not enough heat, but I've only used big 250A migs - maybe the 140 doesn't have the nuts to start off hot?
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When I crank the amps up about halfway its able to give enough heat no problem with this thickness. Its touchy though. Too much amp and not enough feed and youll never get the wire out the gun quick enough before it just shorts. Too much feed, not enough amp, itll dance around on you and not even penetrate.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
I usually run near the same amount of heat as I would with mild, but with much faster feed to keep it from burning through. I also push at ~70 degree angle on lap welds, and ~45 on T welds - that will give you nice sharp beads, just like with mild </TD></TR></TABLE>

Thats very interesting. Lincoln mentions using a 10* angle. Yes 10* - almost all the way vertical. And that seems to work just fine. Im going to have to try using a sharper angle. Maybe even starting vertical and laying it out on the way down or vise versa.

- - - - - -

I did work with speed and heat and I seem to be able to keep it pretty even if I

1. start out hard and fast or
2. fiddle with the amps as I go.

I prefer #1, just like my women.


Modified by random_tuner at 10:22 PM 2/13/2008

 

70 degrees from the surface, so only 20 from vertical

 

I noticed today that I can start almost vertical, then lay it out to about 50* right after and it lays an almost even height bead. I guess keeping it vertical is giving it all the heat then laying it out and keeping a good speed just keeps that heat flowing.
Ugh, Im gettin frustrated with this. Will someone local let me borrow their TIG already?

 

that's the idea with AL - to keep the heat in front. When it drags, it overheats. Instead of moving faster to keep the heat under control, turn up the feed speed (wire = heat sink, more wire = more heat sink = less warpage)

 

That was the reason I thought of laying th torch out more as I went. It seemed to keep the heat out front while using it near vertical kept it right where I wanted it. If I use any more feed Ill punch right through it.
But what you said makes sense. The problem is if I turn the feed up too much and not match the amps, the wire will want to build up too much to keep a nice flatter bead and possibly not even weld at all, just jump around and short out. (if that makes sense)

I just need to get in and practice more. I think I have the speed and amps right - I just need to get a technique that will lay a nice bead, then rotate the piping and repeat - without looking like its all chopped up.


Modified by random_tuner at 11:04 PM 2/15/2008