spray arc and short circuit???

[Srubrn]

I have read the definition of both of these terms and I want to know when do you use them and how? Spray arc and short circuit. I have a MM210

Second question. I was trying to weld some 14ga. square tubing today with my MM210 and I just keep burning holes. I used my HH135 and did fine. I set my voltage down to 2 and wire speed down to about 25. Sounded terrible. I am using .030 wire. 75/25 mix. What gives? Should I be using .023 wire for that?

[Scott V]

Dan,will have to help on the settings,but to me #2 tap should be fine.Play with your wirefeed setting.The wire you are using is perfect size for that gauge.I will let Dan or somebody else help on the spray/short-arc question.When you say it sound terrible how does it sound?

[Srubrn]

The spray arc has nothing to do with the sound.

I was referring to the settings for welding the 14ga. With the setting on 2 and 25 it is barely burning and sounds like water on a fire, kinda hissing. It still burns thru.

It burns thru only when making welds on joints where there is a gap.

I succesfuly welded a piece of 1/4 plate to the 14ga on 4/65 and no burn thru. It's just on the joints where the two pieces of 14 ga. meet and there is a gap.

Dan I would like to know about the first ? in my topic from you.

[deere_x475guy]

Try increasing your arc length just a touch when you come to the gap. I do this when I have a poor fit up in one area that I am to lazy to fix.

Good Luck...
Bob

[Sberry]

Thats why they got that trigger on the gun, you can stop. Lots of times I dont bother (most of the time) to adjust the machine. You can stop for a second and back up and start letting the puddle build up a little to fill gaps. Changing travel speeds and learning to read the puddle surface tension helps if filling gaps. I often tack in gaps. I was doing a project a while back and I filled a web of I beam, about 10 guage, and I could run downhill and fill gap of almost 1/4 inch in single pass. You really had to hang with it and on a couple of them I stop in the middle for a minute which made it easier too. That material and that gap was about all it would do, adjusting machine might have helped a little but I usually dont bother,, but again, I have been doing this long enough that I can make the puddle do what I want it to.

[Dan]

Originally posted by Srubrn
The spray arc has nothing to do with the sound.

I was referring to the settings for welding the 14ga. With the setting on 2 and 25 it is barely burning and sounds like water on a fire, kinda hissing. It still burns thru.

It burns thru only when making welds on joints where there is a gap.

I succesfuly welded a piece of 1/4 plate to the 14ga on 4/65 and no burn thru. It's just on the joints where the two pieces of 14 ga. meet and there is a gap.

Dan I would like to know about the first ? in my topic from you.

Todd

I m not feeling very well (cold) right now, however later on today I ll try to use my MM 210 on some 14 ga with a gap. I ll try voltage tap #2, but from what I taking from your post, Im leaning more toward tap #1. Reason being because since there is a gap the arc needs to be soft on this thickness. So what I want to do is make the arc real tight so that the weld puddle is cold and well set up quickly. Anyway let me try some things and I ll get back with you on my results.

By the way I ll try and answer your other questions later too, but for now I just want to take some medicine and go to bed for a while.

[Dan]

Todd

First of all, let me remind you, that no 2 machines are going to run at exactly the same settings. So, any settings that I provide you with should be looked upon as a starting point.

Anyway, this evening I ran some sample welds for you on some 14 ga. I used an .030 E70S-6 and C -25 just as you stated you were using. You stated you were having trouble with burn thru when there was a gap, so I assumed this meant a butt joint. So, I welded up several butt joints and varied the gap from just slightly to as wide as the thickness of 14 ga.

Now, with tap#2 I started out with the recommended settings on the machine and worked my way down to your 25 setting on the wirespeed, and to be honest with you the only time that I had any problem with burn thru was when I tried to weld up the joint that I gapped the thickness of a piece of 14 ga. Also, at the 25 setting on my machine I didn t experience the metal transfer that you described. In the end though tap #2 was creating to much weld bead penetration on the back side of the joint as the gap widened. So, I tried tap #1 and came up with a setting for you to try. So, what I suggest as a starting point for your gapped joints is tap#1 and 28 on the wire speed. So you know, on my joints that were gapped the thickness of 14ga. even with the machine set at tap #1 I was only able to run about a 3/4" long bead before I experience burn thru. I eliminated the burn thru problem on this joint by using a series of quick tack welds along the length of the weld joint, which allowed the weld metal just enough time to cool so there was no burn thru.

With this post Im attaching 3 pictures of my results. This first picture is of a weld ran at the tap #1 and 28 wire speed setting.

By the way, I will try to address your other question sometime Saturday, because right now I still don t feel very well and need to go back and lay down again.

Anyway here is the first picture.

[Dan]

This next picture is a view of the penetration on the backside of the weld bead in the previous picture. By the way, the gap on this joint was about a 1/16".

[Dan]

This last one is a picture of the wide gapped joint that I used the quick tack weld technique on. A few more joints and I would have nailed this, but I ran out of material. Anyway, my settings for this joint were tap#1 and 22 on the wirespeed.

[Srubrn]

Dan,

Thanks for the help so far. I will try that myself and see what happens.

Hope you get to feeling better.

Looking forward to ther rest of the answers.

[Dan]

Re: spray arc and short circuit???

Originally posted by Srubrn
I have read the definition of both of these terms and I want to know when do you use them and how? Spray arc and short circuit. I have a MM210

Second question. I was trying to weld some 14ga. square tubing today with my MM210 and I just keep burning holes. I used my HH135 and did fine. I set my voltage down to 2 and wire speed down to about 25. Sounded terrible. I am using .030 wire. 75/25 mix. What gives? Should I be using .023 wire for that?

Hey Todd

Sorry about the long delay in responding to your question. I m not 100% better yet, but I ll see if I can give you a good enough response.

Well, as you have read short arc and spray arc are two totally different forms of GMAW metal transfer. Short arc is a shallow penetrating process and spray arc is a deep penetrating. The short circuit transfers weld puddle sets up quickly so it is a good process for out-of-position welding with in the thickness range that it can be used for, and also for open root passes on thicker material. 1/4" and thinner is the thickness range that short arc transfer is best suited for. However, overall 1/8" and thinner is the thickness range that it produces its strongest weld joints on. Of course there are exceptions to this, because of the nature of the weld puddle on vertical up with proper technique and correct parameters very strong weld joints can be created on 1/4" steel. Now the settings for C 25 on the door of your machine are short circuit transfer settings. As you should have noticed there are settings for up to 3/8" material. Personally, I would never short arc 3/8" material, because you can easily encounter lack of fusion problems along the length of the weld joint if your skill level is low. Even short arc on 1/4" material should be used conservatively, it is best to limit your use of short circuit transfer on 1/4" material to non-critical welds that nobodies life depends upon the strength of the weld joint. Spray transfer, gas shielded fluxcore,or a self shielded fluxcore: are better choices over short arc on 1/4" and thicker material for weld joints that are going to receive heavy loads with your MM 210. However, Spray transfer is limited to the flat position on butt joints, and flat and horizontal on fillets. Now a MM 210 should be used conservatively with spray transfer because to spray 1/4" material the machine is being ran pretty hot. 30% should be a realistic duty cycle for spray arcing 1/4" with a MM 210. If a person wanted a machine for moderate spray production work then in the MM line they should use the MM 251. Now, since the voltage output on a MM 210 is towards the bottom range for spray transfer an Argon/oxy gas mixture of 98/2 or 95/5 should be used because these mixtures produce spray transfer at lower settings then mixtures containing argon/CO2. However, a gas mixture of argon/co2 that contains 2% to 5% co2 might do well too, but I ve never tried them so I don t know for sure. Your stickout length for spray increases to about 3/4". You want to use a nozzle that recesses the contact tip an 1/8". This nozzle is available for the M-25 gun on your MM 210. .030 or .035 E70S-6 will work on the machine for spray on 1/4" material.

Todd, Im sorry, but I ve ran out of time for now. I well try to return later and add more if you read this before then please give me more detail on exactly what you are wanting to know.

[Srubrn]

Dan,
I have ordered a book from Miller "GMAW" is the name. I hope it helps.

I was hoping someone could just give me a short answer about both methods of transfer. This sounds awful but I turn the machine on and turn the settings for what the panal says for the thickness of metal I am using and let the wire burn. I use .030 wire mostly. I am considering going to .035 wire. I am welding mostly 3/16" material. I just want to be sure I am doing it the right way.

Any info you can give is a great help and is much appreciated. What you told me so far is great. I guess I was looking for a short answer in laymans terms of what the difference is and when to use them, oh and how to use them too.

Thanks again!!!

[cope]

wire size

Todd, I think I got this from Hobart's main site.