My problem is that when it's not going well, I don't know what am I doing wrong.
Am I too hot,
wire to slow,
Hand moving to fast,
marginal ground connection,
Material not clean enough
wrong type of wire, (with gas-no gas)
wrong diameter of wire,
to close, not close enough to material
Does having a fan blowing on me and the project have a effect in the weld cooling to fast?
I know I have trouble seeing what I am welding, even with the sensitivity turned down
It's hard to tell for sure what the issue is with it being painted.
However, when the weld "puddles" on top, that's a sign of "too's." (You're either Too Cold on the weld or Too Fast on the wire, using Too Big wire, or Too Fast on the hands.) Could be one of those items, or some, or all.
You will know for sure if the polarity is wrong - hard to mistake the sight.
Check the settings from the panel that's probably on the inside of the door where the wire goes on your welder.
As for too close - I usually keep the tip about 1/4 to 1/2" away. 3/8" is probably more ideal - too close just puts a bunch of splatter into the tip and you end up obscuring the arc with the torch tip.
Gotta have clean metal. Gotta have clean metal. Gotta have clean metal.
That goes for the area where you're going to be welding, and the area where the clamp is installed.
As for air blowing on you - this will absolutely cause problems, but typically it just involves welds that look really rough from the outside. A weld bead should be a smooth ball of metal. This goes for solid wire with MIG gas and also for flux-core wire. The shielding gas (either from a bottle or from the flux), if it gets blown away, will have a decided negative impact on the weld.
If the fumes bother you, get a mask that will fit under your helmet. 3M makes some good ones for reasonable $. Probably not a bad idea anyway.
Creating good MIG welds is a balancing act involving voltage, wire speed and tip progress across the welding seam.
Practice on some pieces. Use the chart I recommended earlier as a base - not as gospel for setting the voltage. If the weld has "undercut" edges, turn the wire speed up a bit. If the weld is standing too proud of the surface, turn the wire speed down a bit and slow down. Slowing down will tend to make the weld material puddle more, so you may have to further reduce the wire speed.
Take two pieces of thin material (.040 to .050 thick) and **** them edge to edge - no gap. Set the machine on 3, using .025 (I think that's the #) wire. Set the wire speed somewhere in the middle of the dial. Put one small tack in the middle of the seam to be welded. If the weld burns through or erodes the edge, turn the voltage down one notch. If that results in a weld that doesn't seem to penetrate, turn the voltage back up and increase the wire speed until it doesn't burn through.
Once you get a good weld in the middle, then connect the ends.
Weld the pieces together with small tacks to join the middle to the end. Alternate locations - don't just tack, tack, tack - you'll add too much heat along the seam which will make it easier for the weld to blow through.
If it's done right (and I've had some very small success in this area), when you're done, you can grind the weld away and you won't be able to tell where the actual seam is.
See postings by MP&C for examples of what to do.
As for seeing what you're doing - I've got a couple of Joby lights (
http://www.amazon.com/dp/B002IT5DIU/?tag=atomicindus08-20). They work really good for putting a nice bright spot right where I'm welding. It helps me.
Just my 2 cents from another Houston welder (hobbyist).