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Welding aluminum with Dalex 152

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Gasoline engine
Posts: 4
Registered: 19 Nov 2017, 11:24 am
Place of residence / region: 30900

Welding aluminum with Dalex 152

Contribution from Gasoline engine »Nov 19, 2017, 4:27 pm

Hello you friends of the tool,

Thank you for the quick recording, and here is my first question:
I own a Dalex CGL152 and am wondering whether it makes sense to weld aluminum with it. I realize that AC / DC TIG is the first choice, but what is possible with this MIG device?
The instruction manual says it is possible after conversion. And I've read that MIG / MAG devices need a pulsed current to crack the aluminum oxide layer. That would be levels 1 and 2 here, but 45 amps stop there. At 30 A per millimeter of aluminum that would be 1.5 mm maximum material thickness, or ...
Does anyone have experience with the device?

Best regards from Wedemark
Lutz
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DomiAleman
Posts: 1617
Registered: Jan 29th 2012, 10:07 pm
Place of residence / region: 49451 Holdorf

Re: welding aluminum with Dalex 152

Contribution from DomiAleman »Nov 19, 2017, 7:50 pm

Hello..
With the CGL 152 you can achieve reasonable welding results with aluminum.

You have to pay attention to the following:

You need an aluminum wire that fits the groove in your wire feed roller.
That should be a maximum of 1.0mm, maybe only 0.8mm wire.
There are special conveyor rollers for aluminum wire, the groove of which has a semicircular profile and so does not deform the wire ... but probably no longer for the CGL.

The wire must not be too soft. An AL-Si wire is rather unsuitable for the 2-roller drive, an AL-MG wire works better.

However, due to the manganese it contains, the ALMG wire may have black "soot" at the seams. The best way to get rid of this is with a sharp jet of compressed air.
With the AL-Si, the seam looks shiny silver.

The hose package must be 3m or shorter. 4m does NOT work.

The hose package must be equipped with a Teflon or PA liner. The existing steel core is too rough for the aluminum wire. In the front part of the neck of the torch, the teflon core has a brass spiral so that the core does not melt on the hot contact tip.
The core must lead from the wire feed roller to the brass spiral in the neck without interruption or kink.
A support tube is required for devices with a central connection.
(The Teflon core must go as close as possible to the conveyor roller, but must not rub against it)
The contact tip must be 1 size larger than the wire diameter.
E.g. a 1.2mm nozzle for 1.0mm wire.
Alternatively, you can buy special current nozzles for aluminum wire,
which are stamped e.g. 1.0A (= for 1.0mm aluminum wire).

The wire brake = mandrel for the wire spool must be extremely easy to move.

The contact pressure of the wire feeder must be set as low as is justifiable, otherwise the wire will be pressed flat and will no longer fit through the contact tip.

The hose package must be as straight as possible when welding.

The wire speed has to be significantly higher than what one is used to with steel wire of the same thickness. The CGL152 has a small hook switch on the control board (in the device) for this purpose.

Argon 4.6 can be used as welding gas, nothing else.

The pulsing on the small steps has nothing to do with aluminum and its oxide layer. The problem of "breaking up the oxide layer electrically by reversing the polarity" only applies to TIG welding.

Immediately before welding, however, a stainless steel wire brush is briefly passed over the areas to be welded in order to mechanically break up the oxide layer.

Aluminum is only welded in a piercing torch guide.
dragging the torch position (pulling the torch in front of the weld pool) does not work.

In order to achieve good ignition, the end of the wire can be pinched off at an angle before the ignition process, so that a point is formed.

I wish you success!

DoMi

Gasoline engine
Posts: 4
Registered: 19 Nov 2017, 11:24 am
Place of residence / region: 30900

Re: welding aluminum with Dalex 152

Contribution from Gasoline engine »Nov 20, 2017, 9:20 am

Thanks for the detailed answer!

I'm just amazed at the tip of welding aluminum without a pulse with a "normal" setting.
We tried this with a professional device (ESAB 250A) and had creepy results despite the brushed preparation. Unclean, splashes, caterpillars, etc. You could already hear that something was wrong. Everything changed from current to angle, distance, speed etc, but no nice results.
But I am a hobby welder and therefore seek the advice of a professional.

LG Lutz

Schlorg
Posts: 1184
Registered: Jan 12, 2013, 6:35 pm
Place of residence / region: Erding
Place of residence: Lk. Erding

Re: welding aluminum with Dalex 152

Contribution from Schlorg »Nov 20, 2017, 9:55 am

Hello,

I can confirm the statements of DomiAleman, have my own "knowledge" about aluminum welding, also largely gathered from Domi

I myself have been welding aluminum with my simple, step-switched Lorch 220A transformer MIG / MAG system every now and then with good results. It takes a little practice and if you have had a long break it always takes a while to get the hang of it, but then it works properly. But I mainly make lids for any boxes, brackets and auxiliary structures, where it is not important that it looks so 100% beautiful, such as a ladder or stairs ...

Of course you shouldn't expect the sparkling clean seams to come out that look as if they were made by a robot, but it is quite acceptable for my requirements.

I usually have material thicknesses between 2 and 5mm with 1.2mm wire. Have my own 3m MB-25 hose package with Teflon core, which I only use for aluminum.

AL-Mg wire works quite well despite the 2-roller drive, seldom stalls, but always burns back to the contact tip, I haven't quite figured out how it can be avoided even better. With Al-Si, the hose package has to be very straight, it stalls more often, but results in nicer seams with less stressed components when it runs.

Good brushing is important, sticking the torch at the right angle over the entire distance and, in contrast to mild steel, welding can be done really quickly, the hotter the seam, the faster you have to get.

DomiAleman
Posts: 1617
Registered: Jan 29th 2012, 10:07 pm
Place of residence / region: 49451 Holdorf

Re: welding aluminum with Dalex 152

Contribution from DomiAleman »Nov 20, 2017, 11:36 am

Otto engine wrote:...
I'm just amazed at the tip of welding aluminum without a pulse with a "normal" setting. ...
Hello..
There are welding machines with pulsed arcs.

With these, the following is achieved through a special rapid sequence of different currents with continuously running wire:

The drop transfer is influenced. At the moment when the drop causes a short circuit between the workpiece and the wire electrode, the current strength is reduced so that the drop does not "explode" but passes onto the workpiece almost without spatter.
In addition, there are advantages with low material thicknesses due to a reduction in the heat input. (doesn't burn out so quickly)
The sound during welding is then a long "Tüüüüüüüü" with e.g. 300Hz.

With some devices, a slow pulse can be superimposed on this fast pulse. Depending on the manufacturer, this is called "double pulse", "hyper pulse" or something like that.
It is switched between high and low power e.g. 3 times per second.
The advantage here; you get "show seams" with an evenly flaky seam appearance, which ideally do not have to be reworked.
The sound is a "TüTaTüTaTüTa"

Both pulse shapes have nothing to do with the oxide layer.

With the CGL, the wire feed is switched on and off again in quick succession with the transformer voltage unchanged.
This is said to have advantages in thin sheet welding, but I don't know anyone who has ever used this function meaningfully.

DoMi

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