What is a spool gun used for?

[Badger1bear]

You Kent folk will just about use anything as currency these days

Jack sold his cow for beans
Badger bear swaps monkeys for welders.

What are you implying lol

 

[Badger1bear]

This is what I am talking about, the first pic was when I had the back door shut yesterday so no real airflow in the workshop and soot was minimal. Second pic was with the back door open to cause a through draught as the smoke was building up
As can be seen the weld is clean in both but the soot is much more on the second one, so likely lack of shielding.

Too much smoke with your back door open Mr Hood sounds like a medical problem

 

[Hood]

Too much smoke with your back door open Mr Hood sounds like a medical problem

Well I do have bowel problems but is unfair of you to point that out

 

[Hood]

Ok first test of the day and I do agree light wire brush is best.
First bead is no cleaning, second is wire brush, third is light clean with angle grinder and last is grinding with angle grinder.

Time to move to mig now.

 

[Richard.]

Ok first test of the day and I do agree light wire brush is best.
First bead is no cleaning, second is wire brush, third is light clean with angle grinder and last is grinding with angle grinder.

Time to move to mig now.

Rarely with Mig will you see the problems on the surface.
Unless your getting heavy porosity
I don't use a wire brush even if my stock is clean or new. No need a quick wipe to remove dust/finger prints and away you go.
A lot of what I do requires a good surface appearance and scuffs from brushing would not be acceptable.

 

[Richard.]

Ok first test of the day and I do agree light wire brush is best.
First bead is no cleaning, second is wire brush, third is light clean with angle grinder and last is grinding with angle grinder.

Time to move to mig now.

Bottom two are contaminated. Worst been the very bottom. Even the etched zone looks dirty.

 

[Richard.]

I'd be happy if I could produce a run like that......

No you wouldn't mate. It's not a run I'd ever let go any further than the bench then the bin. Nothing is more of an eye sore than a scabby Alu Tig weld imo.

 

[Hood]

Rarely with Mig will you see the problems on the surface.
Unless your getting heavy porosity
I don't use a wire brush even if my stock is clean or new. No need a quick wipe to remove dust/finger prints and away you go.
A lot of what I do requires a good surface appearance and scuffs from brushing would not be acceptable.

I never have clean stock LOL, I am about 10ft away from the sea. Here is a pic of the road outside my workshop taken on a stormy day.

 

[Richard.]

I never have clean stock LOL, I am about 10ft away from the sea. Here is a pic of the road outside my workshop taken on a stormy day.

Ha ha yes I see half the issue.
I wasn't dissing your method I've just found in the past it doesn't work too good when attacking Alu with abrasives.
Obviously not in your case but the whole "cleaning" thing is well over rated with posts all over the net saying you need to scrub it to death to stand a chance and it's total nonsense. Below is 3mm stock straight off the saw. Not been anywhere near a brush or grinder. Simple wipe with a soft cloth and straight in with an arc. I get best results this way.
Excuse the crator at the end of the fillet that's just my numptyness been a bit quick off the trigger. I'd normally go back and sort that out.

 

[Hood]

Been messing with different things on the mig and sad to say the stainless swarf diffuser idea was a complete failure, it was the worst of the lot at the three different gas flows I tried. I also tried similar to what Jodie did and wrapped some thread tape over the outside of the shroud and body of swan neck but no difference at all.

It is quite hard to be consistent on small test pieces with the mig as it heats up so quickly due to the spray transfer but I decided to keep the voltage and wire feeds the same for each test and only varied the gas flow.
Saw a lot more soot when down to 10l/min on the flow meter, it was right hard to the edge of the weld.
Up to 13l/min and it was better, there was now a gap between the edge of the weld and the soot.
Up to 15l/min and was slightly better if anything but not by much, sadly the Alu was too hot so the weld itself suffered.

Now was time for something different. I remembered I had been given some Alu years ago and it was in the drawer. It is 0.047 inch Dia so 1.2mm or so but the grade was AL-G21 which is 5% Silicone. Man what a change. Had to turn the wire feed way down compared to normal, was only feeding I think at 7m/min whereas with the 1mm 5356 I was up at 11.8.
Ok so it was thicker wire but still the wire feed seemed low.
Anyway no soot to speak of, see first pic.
Next I grabbed a roll of 5356 1.2mm as a direct comparison, had to wind the wire feed up to 10.2 to get the spray going and the soot was back, see second pic.

 

[Hood]

What grade alu do you use, also filler wire grade.
It is all 5083 Alu I use and 5356 wire.
Ok sectional stuff is not 5083 but 6082 but still 5356 wire.

 

[Richard.]

What grade alu do you use, also filler wire grade.
It is all 5083 Alu I use and 5356 wire.
Ok sectional stuff is not 5083 but 6082 but still 5356 wire.

Most of my stuff is 6082 T6.
Mainly 5356 on this but I use a lot of 4043 and now started keeping 1050 too. I don't do Mig at home I don't do any work to require it. 95% GTAW here and 5% mma.

 

[Hood]

Ok thanks for that.

 

[Mee]

Has anyone tried the plastic bristle brushes in an angle grinder? all I do is run one of these down the weld area, degrease, then weld using push MIG, clean welds and a lot less faffing about.

 

[Hood]

Has anyone tried the plastic bristle brushes in an angle grinder? all I do is run one of these down the weld area, degrease, then weld using push MIG, clean welds and a lot less faffing about.

Nope never tried that.
What wire are you using?

 

[Mee]

Depends on material.

 

[Hood]

Wouldn't mind seeing a pic of 5356 if you ever get a chance.

 

[henry Kadzielski]

Good afternoon Hood.
Here are some pics mig 5356 1.2mm wire
below pic is 6mm 5083 vertical up lap joint. Bottom part is up using my outside corner setting as a sample. The higher one is small increase in voltage, but has been wire brushed. All material is out from the scrap bin so has been lightly wire brushed before welding, but nothing else. This is just a quick set up test for a fuel tank repair, just a patch over the crack.

second pic is 6mm 5083 overhead 5356 1.2mm un brushed

third pic is the above wire brushed

 

[Hood]

Ok thanks for that, just been doing a couple more tests myself and I have discovered something interesting, well it is interesting to me anyway

First pic 5mm 5083, 1mm 5356 wire, flat position
Second pic after it has been brushed
Third pic same material/wire but vertical up
Fourth after brush.

Now the interesting bit, piece of 6082 with 5356 wire, 1/4 thick so a bit cold on the weld but the soot is 100x worse. The tests I was doing the last day were all 6082, not sure why it would produce more soot than 5083 but it seems to.

 

[Richard.]

Ok thanks for that, just been doing a couple more tests myself and I have discovered something interesting, well it is interesting to me anyway

First pic 5mm 5083, 1mm 5356 wire, flat position
Second pic after it has been brushed
Third pic same material/wire but vertical up
Fourth after brush.

Now the interesting bit, piece of 6082 with 5356 wire, 1/4 thick so a bit cold on the weld but the soot is 100x worse. The tests I was doing the last day were all 6082, not sure why it would produce more soot than 5083 but it seems to.

That first fillet looks a cracker hood.