- Thread starter Damaged
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Damaged
I blame the penguins.
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Cheers Fingers,
Dosn't help that I spelt it wrong, should have been "Weldap"
Just lugged the sodding thing down the drive so I don't care what it is now, it's going to get used!
Mick.
Ah, just seen Hitch's comment on another post "weldap is crap"
Oh well it was F.O.C. so may as well use it!
Dosn't help that I spelt it wrong, should have been "Weldap"
Just lugged the sodding thing down the drive so I don't care what it is now, it's going to get used!
Mick.
Ah, just seen Hitch's comment on another post "weldap is crap"
Oh well it was F.O.C. so may as well use it!
bigtaloola
Member
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Hi just found this if its any good to you? http://www.airproducts.co.uk/metalfabrication/welding_StandardMIG_MAG.htm
Cheers Dave
Cheers Dave
shenion
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Is it Weldap 5, 8 or 20?
I assume that is the CO2 percentage. 5/8 will produce a bit tall welds on thicker steel but will work fine. Will be easy on thin metal.
Odd, it shows the 5/8 for "6mm or less". We use 5/8 % in the us for spray transfer welds (200A+). 20 or 25% is used for most else as it is cheap and has a good profile.
I use 20% for just about everything here.
I assume that is the CO2 percentage. 5/8 will produce a bit tall welds on thicker steel but will work fine. Will be easy on thin metal.
Odd, it shows the 5/8 for "6mm or less". We use 5/8 % in the us for spray transfer welds (200A+). 20 or 25% is used for most else as it is cheap and has a good profile.
I use 20% for just about everything here.
shenion
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If you do >5mm then it will try to go into globular or spray transfer. That is the perfect gas for spray welds (>170A, used on robotic welds here.) You can use thicker wire and a lower voltage wire speed if you need short arc.
The 20% is for >6mm as it will keep the weld in short arc mode up to a higher current.
The 20% is for >6mm as it will keep the weld in short arc mode up to a higher current.
Damaged
I blame the penguins.
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Ehm, Cheers Shenion, I'm sure that means something to the more advanced people on this forum, me, I just want to glue bits of metal together without it breaking! Seriously, I do appreciate your reply, just haven't the foggiest what "spray transfer" means, if your willing to explain in layman's terms I'd like to know.
Many thanks,
Mick.
shenion
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I suggest you read the Miller MIG Handbook. It has good description of the 3 transfer modes.
Short-arc or Short-circuit transfer is what most DIY welds use. The wire shorts against the weld pool, melts, a drop is pinched off and melts back and repeats. The repeated shorts and then arc causes the characteristic "buzz" on MIG welding.
Spray transfer happens at currents above 170A or so. The arc current is high enough to melt the tip of the wire. The magnetic field pinches off small droplets of metal that are attracted to the work. So, it loos like a "spray" of metal. It is nearly silent and is about 2X as productive in inches/minute of weld as short arc. It is also near spatterless.
It is not perfect, since the droplets are transferred by a weak electrostatic/magnetic force, positional welding is difficult as gravity will pull the droplets off course.
Globular is in the middle and messy. Droplets form irratically on the end of the wire. Causes lots of spatter.
170A is usually about the transition point. There are factors of wire speed, wire diamater voltage and gas that control the points the 3 modes occur. Using higher % of CO2 will keep the arc length shorter and keep it in short-arc mode. A lower % of CO2 will increase the arc current and allow the spray transfer mode to become stable.
I have been meaning to write thes up with videos and volt/current captures. Have a few test videos but need to figure out how to get the closeup lense to work right. I have spent a lot of time analyzing the arc modes in preparation for the DIY welder I did.
Short-arc or Short-circuit transfer is what most DIY welds use. The wire shorts against the weld pool, melts, a drop is pinched off and melts back and repeats. The repeated shorts and then arc causes the characteristic "buzz" on MIG welding.
Spray transfer happens at currents above 170A or so. The arc current is high enough to melt the tip of the wire. The magnetic field pinches off small droplets of metal that are attracted to the work. So, it loos like a "spray" of metal. It is nearly silent and is about 2X as productive in inches/minute of weld as short arc. It is also near spatterless.
It is not perfect, since the droplets are transferred by a weak electrostatic/magnetic force, positional welding is difficult as gravity will pull the droplets off course.
Globular is in the middle and messy. Droplets form irratically on the end of the wire. Causes lots of spatter.
170A is usually about the transition point. There are factors of wire speed, wire diamater voltage and gas that control the points the 3 modes occur. Using higher % of CO2 will keep the arc length shorter and keep it in short-arc mode. A lower % of CO2 will increase the arc current and allow the spray transfer mode to become stable.
I have been meaning to write thes up with videos and volt/current captures. Have a few test videos but need to figure out how to get the closeup lense to work right. I have spent a lot of time analyzing the arc modes in preparation for the DIY welder I did.
