Arc Blow

First of all, arc blow usually occurs along the length of the weld and represents itself as either forward blow or back blow depending on the direction of travel. Another problem, arc wander is a result of a bad ground and the arc will fly around in any given direction. This is usually encountered with AL welding though and can be corrected by cleaning and repositioning the ground clamp. When arc wander occurs while joining two pieces (as in welding two sheets together)you can use your battery jumper cables clamped one end to each sheet to aid in grounding both parts simultaneously.

If you determine that arc blow is indeed the problem here is some additional info on that. (You will have difficulty in eliminating arc blow entirely with wire fed welders because they are DC only machines. In SMAW you simply switch to AC polarity.)

1. Place the ground clamp as far away as possible from the joint to be welded.
2. If forward blow is the problem, place the connection at the end of the joint.
3. For back blow, put the connection at the starting end and weld towards a heavy tack.
4. Position the gun so the arc force works against the blow.
5. Reduce welding current.
6. Use a very short arc.
7. Use run off tabs.
8. Use the backstep method.
9. You can wrap your ground lead around the part where practical to create another magnetic field the opposite of the already existing one.

One of these tricks will generally get you out of your predicament.
Steve

I have also this method on Tig to cut low amps down on a machine that doesn't have a low amp setting and have used this on Mig as a last resort. A drop resistor on the ground lead made from attaching a 1/8" filler rod to the table top and your ground lead on the bottom of the filler rod. This resistor will become extreamally hot, sometimes red hot, so be careful. For Tig you may need a 3/32" rod or 1/16" rod depending on how many amps you want to drop.

T_Bone

I have a few suggestions you can try. 1- This wire is very anglular position sensitive. A slight bit off angle and the wire does not run properly.

2- Gas flow. Too much gas will washout the gases from the flux. Too little gas will not give proper shielding. Swirling gas flow caused by spatter in the nozzle will cause problems such as excessive spatter and blow holes.

3- Run the wire harder. Most of these newer wires are made for high speed production uses. You need to have sufficient amperage in combination with voltage stability. Lowering the voltage may cause more problems than increasing it. The triple 7 in .045 calls for 200 - 250 amps, 25 - 28 volts and 260 - 375 inches per minute. If you're trying to drive a wire that requires say 250 amps and you only have a 250 amp machine, the machine will not have enough guts to drive the wire where it needs to run in amperage and voltage. Start at the lowest settings for the wire you have and work up from there, not down.

4- Check to ensure the wire is designed to run in the positions you are using it. Sounds simple but some wires will only run in one or two positions like V-up and flat or V-down and flat.

5- Check the voltage output of your machine to ensure that it is holding stable while running a bead. Fluxuating voltage will have a detrimental effect on cored wire causing blow outs and burn backs.

6- If you have an arc force control, reduce it to zero. Many machines will allow the arc force control to override the constant voltage circuits making the voltage output very unstable.

7- Pinch effect control. If this is set too low, the wire will not burn off at the proper distance above the weld puddle which allows pools of slag to build up in the puddle and blow out once the heat gets high enough. Setting the pich effect too high burns the wire too high above the weld allowing the flux to be blown away from the weld puddle, thus loosing coverage and allowing air to hit the weld puddle. This will also cause blow outs.

What I would do in order:

1- check the voltage stability of the machine.
2- set the pinch effect and arc force to zero position.
3- set voltage and wire speed to the lowest recommended points.
4- check nozzle gas ports to make sure they are perfectly clean.
5- do not use any type of anti-spatter gel or spray as this may effect the wire even if it is not supposed to.

If the weld is still no good, increase the voltage the maximum or even a bit higher than the recommended and see if this clears it up any while leaving the wire speed the same. If it looks better the higher you get, keep going one volt at a time until it starts to degrade again. You may have to increase the wire speed some but do it in small incriments just to keep the weld running smooth. If going higher on voltage only has no effect, return the voltage to the lowest point again and increase only the wire speed in the same manner as above. You may also need to increase the voltage one volt at a time to keep the wire from sticking or bird nesting. Keep adjustments to small incriments.

If this still does not give you a good result, return the volatge setting where you got the best bead and same with the wire speed. Now you have a base line point for both settings. Once these are set, adjust one at a time a little either way and keep trying.

If none of these tricks work, look for a different machine or wire. Some wires will just refuse to run on some machines. It's a hard fact to face sometimes when you sink a chunk of money into a coil of wire only to find it sitting on the shelf collecting dust because it will not run on your machine. This is one of the hazards of welding. On the other hand, if you only have one choice of wire to use, you may end up needing to buy a machine that run it properly. Every wire mfg will tell you that thier wire is the best and will function with any machine but this is a bold face lie. The charactoristics of the machine is what will determine whether the wire is compatible with the machine or not.