Welding How-to Advice

Ok, long story but I started the current project with a Harbor Freight
Mig welder. 2 days, 10 inches of bead and 8 hours of maintenance
later I got pissed and visited the local welding emporium, where they
fixed me up with a Lincoln SP-135+ and a cart for a good price.
Like night and day. Lincoln units are highly recommended for those
considering buying. Harbor Freight units are not.
Now to the sought-for advice: The situation is a lot of joints
involving a vertical piece sitting on a horizontal piece. It seems
that when I strike the arc, it will jump to either the horizontal
surface, or the vertical surface, but not both, so running the puddle
in the corner where the two meet is not possible.
I'm no welder by any means. Just a home hack. But I've done a little
stick welding and never encountered this problem.
I've been dealing with it by running one bead on each surface as close
to the corner as I can get it, and then running a third bead on top of
those to tie it all together.
Is this anywhere close to correct, or normal?
If it matters I'm using .024 wire and 75% argon, on the advice of the
local shop.
The project is a table, using 2-1/2" square 1/8" wall steel tube for
frame and legs. 2-1/2" is probably overkill for the purpose (table
saw outfeed) but its what I had in the pile, for free, so I'm using
it.
TIA
Reply to
LP
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ground both pieces *very* well, grind them, make sure ground clamp is clean..
I have run into situations where you had to weld a bead on each surface, and one final connecting bead.
Can you post pics of your setup?
Rich
Reply to
aiiadict
Sounds like arc blow; the path of the arc is influenced by local magnetic fields. Try moving the ground clamp to various locations to change the current distribution in the workpieces. I have not had this problem with my similar Lincoln.
Reply to
Don Foreman
Just as a data point... I'm no welding expert either, but I had a SP 135+ and never experienced this problem.
Peter
Reply to
Peter Grey
Afterthought: you really shouldn't have much arclength with MIG at that current level. Try going to .030 wire. Maybe your smaller wire is burning back too far.
Reply to
Don Foreman
0,8mm would be a bit better, but it should work.
what amperage (well I know, MAG is with voltage) do you use? Not connecting to both pieces sounds like not enough current. Do the fillets look like a worm? At what distance (nozzle / workpiece) do you hold the nozzle?
Nick
Reply to
Nick Müller
I just finished running some test beads. Ground clamp is clean, metal is clean, but 2nd piece wasnt clamped to first, just sitting there. Will re-try tomorrow with your suggestions and see what happens. Will get some pics if I can remember to take the camera with me.
Did i mention this stuff is galvanized? I've been grinding it off some joints, not on others, result seems to be the same either way. Yep I've got a big ol' 30" floor fan running air across the area where I'm working.
Just running a bead on a flat piece, it goes where I point it and I get good penetration.
Reply to
LP
Ok I'll try that working on the ground location. The wire burning back also sounds like a possibility altho I've had no problem keeping the arc about 3/8" out from the tip as recommended by the book. I'll have to make a trip to the welding place to get some .030 wire but I'll do it and let ya know how it works out.
Reply to
LP
I dont know what the amperage is. I'm running the machine about in the center of its adjustment. If I go much higher or lower I cant seem to maintain a consistent arc. Nozzle to workpiece is as close to 3/8" as I can hold it.
Reply to
LP
Congratulations on getting a Lincoln. The 135 is an outstanding machine WITHIN ITS LIMITATIONS. (explanation to follow)
HF units are ****.
What you need to do is aim the wire to the piece that is horizontal. Have the heat turned up high. Pause to develop a puddle. Let the puddle flow over to the vertical piece. There is a world of difference between pulling the wire and pushing it. There is also a world of difference in the angle at which you attack the metal.
Now, for what I stated above. Turn up the heat. Use bigger wire. BUT, then you approach the limitations of your machine, which is the duty cycle. That is how much welding you can do before you have to let the thing cool off. Some are very low, like 20%, meaning you have to let it cool down four times as long as you weld.
You may get "cold lap" which is one layer on each other, and not fused together. You need to turn up the heat and get bigger wire, and watch for it to dig a crater, and then fill it up, letting it overflow, and being pushed towards the vertical piece.
It matters big time. Use .030 wire.
You can safely weld this metal with bigger wire, higher heat, higher wire speed, and the "wash" technique. Just weld a bit, and let your machine cool off. It is good anyway to do intermittent welds to keep down the distortion. Do circles to get a bigger puddle, and watch that your heat is high enough that you can see it slightly eat the base metal away at the front of the crucible.
Steve, a weldor since 1974, 6 topside certs, and underwater welding and cutting experience, former State of Nevada Licensed Steel Erection Contractor
Reply to
SteveB
.>Did i mention this stuff is galvanized? I've been grinding it off
Be careful not to blow away your shielding gas with that fan......
Jeff
Reply to
Jeff Sellers
Point taken. I dont think its happening but I'll definitely watch for it. I've done a couple of test beads with the gas off (duh moments) and there's a real visible difference. But I hadn't considered this. Thanks for the heads up.
Reply to
LP
Thanks Steve. General concensus is i need bigger wire and Im off tomorrow to make that purchase. More heat is available and I just have to play with it to find what works.
At what gage or thickness would you use the 024 over the 030? I've got two spools of this stuff and I'd hate to think its useless :)
Reply to
LP
LP wrote in news: snipped-for-privacy@4ax.com:
Should be good for thin sheetmetal work where you do not need, nor want a lot of heat, and you do not have large gaps, nor want a large bead.
Reply to
Anthony
Two things come to mind in addition to suggestions by others:
1) Are you using magnets to hold the work? They cause the arc to chase or run from the magnetic field depending on polarity. You say you've stick welded and didn't have the same type of problem but often the home hobbiest has only an AC stick welder and you don't have the problem with AC.
2) You mentioned in one post that you're using a fan to blow away the fumes from welding galvanized metal. That's a good idea but you need to turn up your shielding has and if the fan's strong you may still blow it all away or at least enough to screw up your weld.
Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com
"I'm not grown up enough to be so old!"
Reply to
Keith Marshall
I was doing just that once, using the larger magnets and I thought Id blown up the welder as the arc was weird as hell and all over the place.
I felt really stupid when the sudden dawning realization of what was causing it crashed into my tiny lil brain.
Shrug
Gunner
"Considering the events of recent years, the world has a long way to go to regain its credibility and reputation with the US." unknown
Reply to
Gunner
"LP" wrote
I, personally, like to use .030 most all the time. Makes it easier than changing wires for different projects. If all you are going to be doing is .065 tubing, or thin stuff, .024 will work. I think the cutoff point will be .125 thick. Once you get the hang of it, you can run your .024 hotter.
Steve
Reply to
SteveB
If you go up with the setting, does the wire feed also increase automaticly? I _guess_ no. Go up with the voltage and play with wire feed. There is really nothing like "nonconsistent arc with too much current". Disregarding that you will burn holes. :-)
10 times the wire diameter is 'bout right. So this is OK.
Nick
Reply to
Nick Müller
That's OK. I never connected the second piece to ground. If it is halfway clean, it will have contact. After the first little weld, contact is perfect.
It should work with the thin wire too. But your diameter is more for body work.
No!
Grind it off on all. The zinc is nasty healthwise and prevents good joints.
don't blow away the gas! Try it without fan.
Nick
Reply to
Nick Müller
Not automatic but increased voltage/feed makes sense after I think about it for a bit.
Reply to
LP

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