I am running scratch start using my Hobart Stickmate ala one of Jody's videos. I am using 3/32nds gold band tungstens, #5 gas lens cup, 15 CFH of argon, mostly 120 amps. I am quenching in water every 2-3 beads or so. I feel a lot more comfortable welding beads on the thicker steel and feel like I am getting more consistent, although I still can't determine how to get rid of the crater yet. But 1/8th plate is really driving me nuts, at anything above say 90-95 amps, the beads are overheated and undercut. I have tried moving faster, using a larger filler rod and doing a forward backward kind of motion, all with no luck. I keep getting advice that I need to run 120+ amps on the 1/8th plate, but everything gets way too hot. The third bead on each of the 1/8th inch coupons is @90 amps. everything else is 120 amps. On the 1/8th inch coupons I quenched after every bead.
What am I missing for the thin stuff (besides a foot pedal, which I know will be someone's first answer) and how do I avoid craters without a foot pedal?
GreinTime
- GreinTime
-
Weldmonger
-
Posts:
-
Joined:Fri Nov 01, 2013 11:20 am
-
Location:Pittsburgh, PA
Think about this man. If you weld at 125 amps on 1/8 you would get full penetration. When joining metal, this is desired. Stacking beads on a plate there is no joint per se, just that single 1/8 piece of metal. At 125 amps you would be sucking back from the bottom side due to the fact that there is enough heat in the weld arc to melt through 1/8 steel and get full pen.
Shoot for 120-125 on joints, turn it down a notch for padding beads. And as you stared before, a foot pedal would solve your problems with amperage control. I rarely use full pedal even if I do set the machine to 1a per thousandth after I get the puddle rolling.
--Sam
Shoot for 120-125 on joints, turn it down a notch for padding beads. And as you stared before, a foot pedal would solve your problems with amperage control. I rarely use full pedal even if I do set the machine to 1a per thousandth after I get the puddle rolling.
--Sam
#oneleggedproblems
-=Sam=-
-=Sam=-
- Braehill
-
Weldmonger
-
Posts:
-
Joined:Sat Jul 06, 2013 11:16 am
-
Location:Near Pittsburgh,Pennsylvania. Steel Buckle of the Rust Belt
Louie,
It's very hard even for an experienced welder not to get a crater at the end of a bead while trying to scratch start on plate. Usually while welding a joint in pipe or plate you can weld out of the joint or slightly overlapping the end of your last bead. Sometimes you can weld into what they call a run out tab that gets removed after the weld is finished. Try welding out to the edge the plate then go 90* onto your last bead and break out of your weld. This is much harder to type out than it is to actually do.
I hope any of this makes sense.
Len
It's very hard even for an experienced welder not to get a crater at the end of a bead while trying to scratch start on plate. Usually while welding a joint in pipe or plate you can weld out of the joint or slightly overlapping the end of your last bead. Sometimes you can weld into what they call a run out tab that gets removed after the weld is finished. Try welding out to the edge the plate then go 90* onto your last bead and break out of your weld. This is much harder to type out than it is to actually do.
I hope any of this makes sense.
Len
Last edited by Braehill on Fri Jun 27, 2014 1:01 am, edited 1 time in total.
Now go melt something.
Instagram @lenny_gforce
Len
Instagram @lenny_gforce
Len