miller 180 mig

[HAWK]

Originally posted by cymax
i see
so in my case using co2 and .035 s6 wire
do you think i should leave a root or should the machine go right trough

A small open root and 45 degree bevel with a slight weave as discussed earlier should get you good penetration up to 1/4".

[cymax]

i see
so in my case using co2 and .035 s6 wire
do you think i should leave a root or should the machine go right trough

[HAWK]

cymax,

It all depends on circumstance: Machine amps, wire size, weld style, type of shield gas, or flux cored wire. As a generally rule an open root provides better opportunity for 100% penetration.

[cymax]

thx guys this really help
i figured out y i did not have any penetration
when welding 3/16 i did not leave a small root opening
so the pudle did not have any place to go but build up
i left a small root opening about 1/16 and it made a differance

i read in a welding manual that for anyting biger than 1/8 one should leave a small root opening
is that true or is it just a recomendation

[Paul Seaman]

cymax: hawk is right on the money, my technique for the penetration is count 1-2 then fast across the middle and 1-2 and back fast across the middle. This should give nice penetration with a v groove, I had a 110 volt red wire feeder and on 1/4 I could do multiple pass with out even doing v groovin. Good luck and practice some on scrap. weld well

[HAWK]

cynax,

Try the double v groove and leave a small root opening. You will probably have to weld on one side and then the other to keep warpage to a minimum. However, 180 amp machine should have no problem with complete penetration on 3/16 steel be it a butt, lap, or fillet in or out of position on a single pass. I think we are both missing something here.

Maybe you are running too fast with the mig torch. Give it some time to burn in. Give your torch movement a slight side to side weave. Don't go very wide at all. Move just enough to keep the heat on the joint without piling up the weld. Try this and let us know.

[cymax]

yes you did thx

i was doing some destructive testing and it seams that when i bend the plates
root bend the weld give it seams when i take a look it looks like there whas very litle penetration the type of joint was sa simple but weld with not prep done
i did not leave any root oppening
could that be the problem

[HAWK]

cymax,

co2 will give greater penetration than 75/25 all other factors being equal. It is hard to say for sure, but it sounds like 20v at 150 amps should give good penetration. You will have a better feel by watching the puddle than the meters. If the puddle is flowiing well and looks like it is penetrating, then it probably is. If the bead is cherry red and fairly flat after welding, then you are penetrating. If the bead is all humped and standing on top of the work piece, then you are not getting penetration. A 180 amp unit should not have a problem penetration 3/16" in a single pass and will probably do 1/4" in single pass. If you are in doubt "v" the joint on both sides and weld on both sides. This is called a "double V groove" joint. Perhaps leave a slight (1/16"-1/8") open root.
Let me know if I answered your quesion. I apologize for not having read your other post on tuning in your welder.

[cymax]

Hawk i think i asked my question wrong and did not give enough info

firs i am welding mild steel .188
i have read that for a but weld you need to prepare the joint with a V if you material is over 1/8 thick

second
the system that i use posted in my last post was for finding the sweet spot of my welder

i have found that setting the wire speed at 50% and turning the voltage to 6 would give me good results for my aplication .188 thick steel


from what i can see i am puting out ~20 volts and 140 ~150 amp
do you think it's enought power for full penetration

BTW i use strait co2
have not tried c25 yet

[HAWK]

cymax,

The machine settings for voltage and wire speed are rough numbers to get you in the ball park. Yes it is possible for a recommended setting to be hot. Perhaps keep the numbered voltage setting and turn you wire speed down a little. Also drop a number on your voltage and turn the wire speed down some more. Somewhere in there you should find a setting that works for your material.

I don't think a voltage meter will really help you. You need to set the machine by the recommended settings and dial up or down to get what you need. Even if you know the exact voltage and wire speed you still may be too hot or cold. Every machine welds different.

Try this and let us know what happens. What material thickness are you welding. Is it mild steel. What type of joint fit up ar you using: butt, lap, fillet?

[cymax]

hello

i currently own a miller 180 mig welder
i use strait co2 as gaz and .035 s6 wire

my question is
when i use the setting recommended by miller the seam to be a little hot
is that possible

my second question is
is it possible to add a volt metter to the welder in order to monitor the arc voltage
ei set the voltage firts using the volt vs amp curve and then set the wire speed

ex: voltage setting on 6 and turn the wire speed up unitl i reach between 19.5 volts from the volt vs amp curve it gives an oupute of about 150 amps