Mig welder questions

Over the holiday weekend I took the interior out of my 67 to find the jackass previous owner had sprayed a heavy undercoating over the floorpans.
Once I hit the front pans with a wire wheel it was quite apparent there were rust holes under the undercoating. I took the front pans out and now need to understand the best welder to purchase for my money. I have no previous experience welding but I want to learn. I basically need a welder to replace the front pans, fill in holes in the quarter panel from an old school slide hammer repair, and to possibly weld in sub frame connectors. I see mig welders at Harbor Freight and ebay for $160.00 and for that cost I know it will at least pay for itself the first time I use it. Will these less expensive mig welder be enough or should I just have someone weld in the panels to keep the clutter out of my garage? And if I should purchase a welder what should be the minimum amperage
 
If you do buy a new one...or maybe a used one...i would go with a lincoln. Great welders. The amperage is adjustable. It all depends on what type of metal. Too much you melt a hole right thru the metal. Too little and its not very strong. As for clutter, there wouldnt be much if you were referring to the welder. Before you do any welding make sure you understand the basics of it and how it works. It can be very simple if you do it right. Good Luck!
 
if you are going to limit yourself to sheetmetal work only, then the cheap welder from harbor freight will do fine. just remember that if you choose the cheap one, you may be limited to useing flux cored wire, and for that you will have to get a chipping hammer as well as a good wire brush to make sure the welds are clean.
 
A mig welder uses a solid wire with a shielding gas.A flux-core uses a hollow wire with the flux in the middle which burns when you weld providing the shielding.Both are wire feed.Since the flux-core wire needs to be hollow the smallest diiameter is about .035.The mig I use has .023 wire in it and is much easier to weld sheetmetal with the smaller diameter.I had a cheap flux core welder for a number of years and it worked fine but I could never get it to work well on sheet metal thicknesses.I bought a Lincoln Mig Pak 10 which can be run as either a mig or flux-core but I only use it as a mig and it is much easier to weld thin stuff.If you buy a cheap flux-core,see if you can try it out first on thin metal to make sure you won't be disapointed.Lincoln,Miller and Hobart all make good machines that will hold their value.If you are beginning you might also want to consider an auto-darkening welding helmet.
 
351LX said:
A mig welder uses a solid wire with a shielding gas.A flux-core uses a hollow wire with the flux in the middle which burns when you weld providing the shielding.Both are wire feed.Since the flux-core wire needs to be hollow the smallest diiameter is about .035.The mig I use has .023 wire in it and is much easier to weld sheetmetal with the smaller diameter.I had a cheap flux core welder for a number of years and it worked fine but I could never get it to work well on sheet metal thicknesses.I bought a Lincoln Mig Pak 10 which can be run as either a mig or flux-core but I only use it as a mig and it is much easier to weld thin stuff.If you buy a cheap flux-core,see if you can try it out first on thin metal to make sure you won't be disapointed.Lincoln,Miller and Hobart all make good machines that will hold their value.If you are beginning you might also want to consider an auto-darkening welding helmet.

I agree with 351LX, I have a lincoln 100amp that I have used for 10 years now and it works great on the small stuff. I recently bought a Hobart 175 amp for the thicker work on the frame of my '46 Pickup. Between the 2, I would say the Lincoln is a better quality unit.

PS the 100 amp will do anything on the Mustang.
 
Personally, I run a Lincoln SP-175 Plus. I can run solid or flux core, but I almost always run solid with shielding gas. With .023 wire it's awesome on sheet metal, and it can handle up to 1/4" easily, which is thicker than you'll find on almost any automotive application.

The auto-darkening lens is worth every penny. I used a regular helmet for a long time, and a few weeks ago I got an auto-darkening replacement lens system that fit my old helmet for $75 and it rules.
 
Gas shielded is the way to go. It’s easier to get up and welding on thin stuff and it’s a much “cleaner” weld. Flux-core has lots of splatter.

Both will get the job done but I still have a hard time welding thin sheet metal with my Lincoln flux-core welder. The difference in the two is about $100. It’s money well spent IMO.
 
I have a Lincoln SP125 and it has done all of the welding I have ever needed done on my Mustang--including on the rails. The other nice to have item (not a must have) is a Plasma cutter. I went with a Miller for that and it is the second most awesome tool I have (behind the Mig welder). The other guys are dead on with the auto-darkening helmet recommendation and with using solid wire/CO2-Argon mix shielding gas. Good Luck!