Gaining Experience With Small MIG - Now Have More Questions

I just finished a project involving using my trusty Handler 120 for
modifying a trailer constructed of 3/16 inch angle (2 X 2 and 2 X 3).
With some last minute advice from Ernie and a few other great folks on
here, I got really satisfying results. Compared vertical up and
vertical down, tried overhead (ended up turning the trailer over to
cure that problem).
But success has bred curiousity. I've seen the recent threads and
searched back through the Group on the emergence of newer and better
dual shield wires and the debate over MIG for out of position work.
And I've got the itch to just do some experiments and practice on stuff
around 3/16 up to 1/4.
My first question involves multipass MIG for say 1/4 stock. I've
tested my machine on 1/4 before, butt joint V-ed out, Hobart HB28
(E70S-6), and C25 flowing 25cfh. I tried to join pieces with 2-3
passes and found that as I watched the puddle and tried to judge
penetration I would end up building the bead into a single pass weld.
Whether I traveled fast and did multi passes or went slow watching the
puddle/penetration and ended up with a single pass the results were as
expected - I could break the weld with repeated impacts due to
insufficient penetration. In fairness to that exercise I was using .030
wire and have since switched back to .024.
Is there some technique for running a multi pass with this size welder
that I'm missing? Based on the experience with every project so far, I
have gotten better penetration by traveling slowly to pump in heat and
get penetration - too slowly to avoid building up the weld all in one
pass. Should I set up the work pieces with a root gap? Leave a land of
1-2mm at the root of the bevel? I know the benefit of preheat from
reading and using in some projects, but I want to try some things out
for situations where the work can't be preheated easily.
Second question involves out of position MIG. Just for trying to
educate myself and build on my skills, would it be worth trying a roll
of E71T and practice some out of position? From what I've read, that
wire will still serve well for most of the general mild steel projects
I come up with.
Third question: Even though the Handler 120 lacks the ooomphhh for
.030-.035 wire when pushing the machine's upper limit, would it be a
foolish exercise to try out some .030 dual shield working in the
mid-range of the machine's ability? That's where much of my projects
fall and again I figure the wire wouldn't go to waste. I've also never
had a problem running .030 when working stuff less than about 1/8 inch.
TIA,
Mark J
Reply to
Mark J
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You need to keep your wire stick out as short as possible, especially on the root pass of a multipass weld.
A root pas should be a stringer pass (no weave) run quickly down the center. Second pass gets a weave to spread out the bead and wet it onto the sides.
The JW Harris "20-gauge" brand is the only dual-shield you can run in your handler . That is what they designed it for.
Don't try to run 0.030" dual shield, even if you could find it.
The smallest regular dual shield I have found is 0.035", and that takes a 220 volt MIG at least.
Reply to
Ernie Leimkuhler
If you are interested in learning from experience, the least expensive way is to learn is from the experience of others. For metals thicker than 1/16 and for multipass welding switch to self-shielded flux core wire. A 120 volt Mig works OK with sheet metal ranging from .024 - .0625. C02 will allow for better penetration. Thus far I've owned five welding machines Mig, Tig, Stick, and Flux-core. Accept the limitations of your machine and practice, you are already in the market for bigger mig. Hope this helps..
Reply to
John D
Ernie, I swapped for a Lincoln Weldpac 100. What is the proper wire to use for this, both flux core and with CO2? I have a number of gas valves and Im planning on putting one in. I have the schematic.
I think its loaded with .030 or .035 flux core at the moment. (previous owner) and have several full 10lb spools of whatever is in it. I think...think its .030
Gunner
Rule #35 "That which does not kill you, has made a huge tactical error"
Reply to
Gunner
110 volt MIG machines should be loaded with 0.024" ER70S-6 for use with C25 or CO2 shielding gas.
For self shielded flux core use 0.030".
It is tempting to use larger wires, but small machines can't maintain the power output with larger wires.
Reply to
Ernie Leimkuhler
Thats exactly what I needed to know. Many thanks again for your willingness to share your expertise.
The little Weld Pac is mounted under one of the shop workbenches for quick tacks and fast repairs on small stuff that dont need carrying out to the welding area.
Have you ever considered writing a Newbie FAQ on the typical questions like this?
Gunner
Rule #35 "That which does not kill you, has made a huge tactical error"
Reply to
Gunner
OK, Latest update for those that are interested. Cut some pieces of 1/4" flat stock to practice on. Beveled the joining surfaces to a little wider than 45 degrees. Running ER70S-6 .024 wire, 25 cfh C25 gas and setting the Handler to Volts 4 and Wire from 7 - 9 (experimenting) did some quick root passes and then played with straight stringers and weaving stringers to fill the groove. Other than heat shrinkage drawing the pieces out of alignment (no surprise there) the weld looked good. After the first root pass, I couldn't break the pieces apart by any hand held method.
Three passes to fill the groove and all looked good. I got a better feeling for not filling up the groove in one pass and saw how different weave patterns work/don't work.
Also tried some 1/8" flat stock V'd butt joints. The Handler 120 settings chart recommends voltage at 3 and wire speed at 4-5 compared to V 4 Wire 6-7 for 3/16 (Ernie recommended Wire 7-9). I ran a joint at the same setting as for 3/16 at Wire 7 and then at the machine's recommended V3/W6-7. I couldn't tell a big difference on the 1/8 stock, even looking for undercutting at the edges. It "sounded" a little happier at the lower settings on 1/8, but both ways looked good and left a good bead profile on the work.
Too bad all welding can't be flat on top of a work table.
Reply to
Mark J
Oops, on the 1/8" stock I meant I used V3/ wire 4-5 as per the machine's label recommendation instead of wire = 6-7
Reply to
Mark J

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