Help with flux core vs gas shielded for penetration

[Harley55]

I have a Miller 170, am self taught with the help of some coaching from some industrial maintenance friends. I currently run gas with my rig and plan to build a 5 by 8 foot trailer using 2 inch by 3/16 inch angle (will use lap joints for maximum weld surface area). I have been told that I will get better penetration if I switch to flux core for this project. The trailer will carry my motorcycle and the last thing I want to see, is it fall apart going down the road (not to mention other’s safety).

Any suggestions, weld with the gas or switch to flux core? Is there a significant difference in penetration? Any help would be appreciated. Thanks
This will be my first BIG project.

[Heavy D]

With that light gage metal and not much weight on it you should be fine with sheilded gas no worries as long as the welds are good. If you have any doubts overload the trailer with sand or dirt and take it for a test run before you load the bike on it. Good luck and keep on burning

[fun4now]

i agree the 170 should be fine for the job. the flux core may give a little bit better pen. on rusty stuff but if its new or clean steel then C-25 should be fine, Co2 being a little hotter. what gas are you using?? Co2 is a little hotter and bit better on not so clean work.
any of the options should be fine with the MM170 for this if you make a good weld.

[Fat-Fab.com]

I think the answer depends on what type of machine you are using. Flux core usually produces more penetration to the point that hard wire is running hot enough and with the right gas to get out of short arc and into spray arc.

If the machine is not capable of or you do not have experience with spray arc and hard wire then I would defiantly recommend FCAW process.

At a given voltage .030 wire hard vs inner shield, inner shield will penetrate deeper with more total energy (read heat) than the same .030 hard wire. (less energy used in melting the hard wire)


As with most questions about welding the answer is not simple, I would recommend before welding on the trailer with either process you make up some sample joints and stress them till something fails (hopefully the base material) then you will have true idea of the ability of yourself and the process)



Good luck


now some one will come in and contradict every thing I said because they once welded some pos and it aint falled apart yeat.

[fun4now]

now some one will come in and contradict every thing I said because they once welded some pos and it aint falled apart yeat.

LOL , that classic.

[Laiky]

i agree with Fat-Fab but don't think it will make a difference with a 170 on 3/16 material. More likely your decision will be based on how clean the material is if you weld out side. That said i used to run .045 fc on a hd lincoln 220 machine because it gave me better penetration and welded thicker material than c25.

[kiwi]

I just completed my trailer using my MM-210 and C-25. I did exactly what was described. I made some test coupons and attemted to destroy them. Interestingly enough I discovered that the recommended settings inside the door of my MM-210 were not "hot" enough. Your Miller 170 is quite capable of welding 3/16" steel using gas.
Good Luck,
Nick

[arc]

ok first off i dont want to make any waves or pissoff any one but fuxcore wire is actually ment to be used in globular transfer, but works great in spray mode as well. and for ur question ur mig will be just fine just turn her up.