Hi guys,

I was practicing MIG welding this morning with my Hobart 140 and 75/25 mix (if that matters). I noticed that I was burning through on the mile steel piping. I was welding a short section of mild steel pipe to a section of stainless steel pipe, but I noticed the burn through only the mild steel pipe. Is MS just easier to burn through, or are my chances of burning through the same with MS and SS?

I had my welder set to voltage - 2, wire speed - 30, wire tension - 2, and 75/25 flow rate is at 20 CFH. Someone said that I should lower the voltage setting, but what about wire speed, tension and gas flow? how would changing those others affect the quality of the weld?

 

oh yah, here are some pics I took of my crappy welds. The spatter you see is from when I was practicing flux core welding. The solid beads are from when I was MIG welding. The bottom pipe is the mild steel one, top is stainless steel.

First pic, looks good IMO.


Second pic, you can see where I burned through on this one.


Third pic, I set the voltage to #1 and speed to 25. But by now I was having problems holding my position, not being able to see through my helmet and lens fogging.

 

phew! Those aren't lookin too good

Any idea what 2 and 1 equate to in volts?

 

Um....practice some more first. it's hard to tell whats going on at all right now. Just work on the being steady first. report back soon.

 

looks like you need your feed up and voltage down, or you need to steady your hand more and slow down a little bit. It takes a little getting used to.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B2CivMan &raquo;</TD></TR><TR><TD CLASS="quote">looks like you need your feed up and voltage down, or you need to steady your hand more and slow down a little bit. It takes a little getting used to.</TD></TR></TABLE>

I'm not sure what voltage 1 and 2 are, I have the manual but I dont know how to convert it over. Right now my biggest problem is my position. The pipe was laying on the ground and I was trying to get as close as possible while kneeling down in front of it. And in that position I have a lot of backlighting and glare coming through my helmet.

 

You should quit wasting time and materials working with pipe...and practice on plate first. Just weld beads, one after another on plate.

You are welding like a blind man....... you will hear many people say to "just go a steady speed".... but they dont mention that you regulate the speed by the size of the puddle. If the puddle gets narrow, you're likely going too fast. If it's too fat, you're likely too slow.

WORK THE PUDDLE, don't let it work you. At some point, you will have a time that it all suddenly makes sense and you can see what the problem is. For now, you're having a hard time because while you may be watching what is happening, you are not making it happen.

 

hehehe that's true Enloid, I'm pretty much welding blind. I adjusted my helmet so that I can nod and have it fall into place, but then I still gotta put up with the backlight and my reflection. I'm gonna get an old black T shirt and cut it up and tape it to the back of my helmet. I put one up there and it got rid of the backlighting. I dont know if getting an autotint helmet will help me out. My main problem is having the torch move away from the seam I'm welding. In the first pic I went through it pretty fast but I could see the bead as I went along. On the second pic I could barely see where the pipes met, and in the third pic I couldn't see the pipe gap at all.

I also need to get something good to work on cause welding on the ground is killing my back. I'm also gonna check out my local welding shop and see if they have any spare SS plates they can sell me. I'll use those to practice on and see if I can steady my aim.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Engloid &raquo;</TD></TR><TR><TD CLASS="quote">You should quit wasting time and materials working with pipe...and practice on plate first. Just weld beads, one after another on plate.

You are welding like a blind man....... you will hear many people say to "just go a steady speed".... but they dont mention that you regulate the speed by the size of the puddle. If the puddle gets narrow, you're likely going too fast. If it's too fat, you're likely too slow.

WORK THE PUDDLE, don't let it work you. At some point, you will have a time that it all suddenly makes sense and you can see what the problem is. For now, you're having a hard time because while you may be watching what is happening, you are not making it happen.</TD></TR></TABLE>

Agreed! Weld some beads on plate, or atleast, just run beads on the pipe and forget about the butt weld-age!

I remeber when I started MIG'ing I had such a hard time with butt welds, now I can weld them up without any problem be it pipe or plate in any position. Practice practice practice!

 

Also the pipe you show in the picture looks like it has a satiny finish on it that is typical of aluminized steel. Are you sure thats just a carbon steel pipe? Aluminized steel has a very thin coating of aluminum and silicon with a thin alloy layer below that will melt at lower temps then regular carbon steel.


Modified by Just Checking In at 3:55 PM 5/13/2005

 

wow they look so ugly, yet so familiar, exactly what all my pipes look like when i try to do a butt weld, , i suck at butt welds too haha

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Just Checking In &raquo;</TD></TR><TR><TD CLASS="quote">Also the pipe you show in the picture looks like it has a satiny finish on it that is typical of aluminized steel. Are you sure thats just a carbon steel pipe? Aluminized steel has a very thin coating of aluminum and silicon with a thin alloy layer below that will melt at lower temps then regular carbon steel.


Modified by Just Checking In at 3:55 PM 5/13/2005</TD></TR></TABLE>

It's either aluminized piping or mild steel. I bought it from Autozone in the exhaut section. I asked the guy if it was mild steel and his reply was "uhhh...yes". So that means that it probably isn't mild steel.

 

Hey guys I did some more practicing today. I welded a few beads on the spare SS pipe I had. I still had my same non autotint helmet, but to get rid of any backlighting I took some black cloth and taped it to my helmet to cover the back. Also It was afternoon, so I layed the pipe down in the sunlight and I kept my helmet in the shade. When I did that I could see through the lens just enough so that I could see the pipe before I actually started welding. I also got reall close and managed to get into a comfortable position/stance.

here are the pics:

gas flow - 25 CFH
voltage setting - 1
0.30" 316L wire
went straight left to right..."dragged" the torch



gas flow - 25 CFH
voltage setting - 2
0.30" 316L wire
top two beads: went straight from left to right...dragging torch
bottom bead: went right to left, zig-zag, pushed the torch


what do you guys think?




Modified by BlueShadow at 2:27 PM 5/14/2005

 

Hey guys,

My friend that knows how to weld gave me some more advice on welding SS. He recommended I turn up the voltage and speed a little to get more penetration. He also told me the difference between the welds I did before, and how to improve. He told me that you can tell that the weld has good penetration when it is flatter. So I turned up the voltage to #3 on my Handler 140 and upped the wire speed. You can see the result is in the following pic. My previous welds in the above post didn't penetrate all the way through, but this next ones did. I could see the beads on the inside of the piping.

The top bead was at voltage #3 wire speed 40, the lower two beads were at voltage 3 and speed 35, gas CFH was at 25.



what do you guys think? I think these ones are a big imporvement over my others.

 

oh yah another quick question I had. Should I purge my gas lines when I'm done welding? before I would just close off the cylinder **** and afterwards purge the gas line. I'm I'm only welding again in a few hours, should I bother doing this?

Thanks

 

uhh the purge thing.. it's a safety thing... but if your just gonna start up later then don't bother.

and yes they look alot better. nicer heat setting that was your problem from the first post... way to cold for the wire speed you were useing.