I have a 90 amp Harbor Freight flux core welder that I got for free. Has anyone used one of these? I know flux core wire doesn't make a clean looking weld but was wondering if it would be good enough to weld in the metal for the 2x6 rock slider mod? I also have an old Lincoln stick welder if that would be better. I know a Mig welding setup with gas would be the best choice, but that is around $1000 including the argon and tank. I am new to welding so this will be my first welding project. This is the 2x6 rocker mod I am referring to for those of you that don't know.

They are junk even for free.

I picked up a Hobart 140 Flux/Gas unit that works with 110v and I think 220v for $200.

This has been touched upon in the welding discussions in fabrication. Most of the resident experts here think the harbor fright welder is not up to such tasks.

Would it be possible to do that with the stick welder then?

i'm pretty amateur as well lol but i believe it would be. Post that question in the welding thread to get a much better response. I get alot of good info from that thread

No. Using rod to weld sheet metal is going to blow through and make a big mess. Mig works well because of the shielding gas and if you use flux it makes a mess but better manageable.

I'll be the person who says never by a flux mig. If you can convert it to gas, cool. If not, dont waste your money on it. IMO flux is just terrible. Save some money, buy a used gas mig, be happier at the end of the day. As they say around here, buy once, cry once.