gas verses intershild

[waxman]

Is the weld from gas & solid mig wire as strong as or stronger then a weld from innershield flux core wire?

[G Austin]

That is a little generic to answer but here are some thoughts. Each process has advantages and disadvantages. The ability for each process to produce sound welds is more related to the proper setup and application of the process and the skill of the welder than it is the process alone.

Self shielded flux core and Gas Metal Arc wires are both rated for given tensile strengths.

A 70,000 PSI FCAW-SS wire and 70,000 PSI GMAW wire will both produce welds that will "Pull Apart" under similar loads. One thing to understand is that the filler metal chemistry can be changed to also improve other mechanical properties. Impact strength and ductility can vary widely among 70,000 PSI wires of both processes.

GMAW has various "Transfer Modes" which can affect the ability of the process to penetrate, weld out of position, produce splatter and other properties. The mode I will use for comparison is short circuit mode. A great deal of information on this is at
http://www.weldreality.com/MIG_flux_core_data.htm

GMAW short circuit transfer mode is often limited to 1/4" in thickness by some manufacturers specifications I have worked with. This transfer mode is the mode used by most welders "Around the house". It's great for sheet metal and lends itself to welding out of position.

FCAW SS filler metals have many classifications and each wire type has operating characteristics that affect the way it welds. E-71T11 is a commonly used general purpose wire. I like this wire because of its ability to make quality downhill welds on carbon steel. The slag that is formed is light and the arc is very deep penetrating. This wire is often limited to how thick of material that can be welded due to the buildup of chemicals in the deposited weld metal due to multiple passes.

Self shielded Flux core has been completely prohibited by some company specifications however, this process and filler metal classification has been used by a fabricator to weld industrial fans up to 110" in diameter.

One thing I don't like about some of the self shielded wires is the fact that it is very difficult to weld over the self shielded weld metal with other processes.

IN general one process is not "STRONGER" than another. Each has advantages and disadvantages which are very numerous to mention right now. It's kinda like "Is a four wheeler faster than a Jet Ski ?" It depends on how/wher you use them.

[waxman]

Just wanted to know the difference if any.
My son had a roll cage welded into his race car and the instructions said not to use a flux-cored wire for this. I had him go else where to have it installed for safety reasons. I am new at this and did not want to take any chance's with something of this magnatuide.

[ZACHV]

Waxman, maybe the place that said not to used self-shielded was afraid of slag inclusion or something. For a roll cage I also suggest GMAW because most roll cages run in the .120" wall thickness range which falls well withing the GMAW range. A quality weldor will produce a quality weld with this scenario.
Flux core is generally accepted as a deeper penetrating weld, especially with a smaller underpowered machine, but for your application a good 175 Amp machine will have full penetration if used correctly.