would a 90 amp flux wire welder be enough to weld on quater panels?

A 90 amp welder will weld sheet metal just fine. Just do it in short strips so it doesn't warp. You will find that flux core wire is very dirty and requires a lot of cleaning and gives off a lot of drops and splatter. Get a can of spray to prevent the splatter from sticking to the area around the weld. Dennis

As mentioned, it can be done. The welder size is OK, but I would highly recommend solid core wire .023" diameter or .035" as a second choice. Then run some type of shielding gas. Flux core is much harder with thin body panels

Flux core can leach through filler and primer and cause problems down the road.

the welder doesent have provisions for gas is there a way I could modify it to take gas?

Have you ever performed any major body panel replacement? Contrary to what some believe, quarter panel replacement is not an easy job, nor is it for the amature body person with little experience with such jobs.

It's very easy to destroy an expensive replacement panel, or worse yet, a valuable part of the car that is basically unreplaceable, if you make a mistake with the install or your welding.

It sounds like your welder isn't setup to do such a job. If you have the experience, then buy a better gas shielded Mig welder. if your skills are questionable, I would suggest you farm out the panel replacement to an experienced shop. This could possibly save you some heartache as well as money in the end.

I don't mean to sound so negative, but this type of work isn't as easy as it sounds...not to mention it's dirty hard work ;) .

Originally posted by chevelle 71:
the welder doesent have provisions for gas is there a way I could modify it to take gas? The main part of the welder which needs to be ready for gas is the gun. If you have that, you can use an electric solenoid and a small control circuit to feed gas (once you also buy a bottle and regulator). If you are good with minor mechanical modifications and light electrical work it can be done.

The other thing which no one mentioned in previous posts is that this should be a "good" 90 amp welder. If you are planning to buy a Wal-Mart Special, it will probably not have enough control to make good welds like you need. I bought one years ago out of desparation and it was so lousy that I took it back and decided to build my own from scrap parts and an old transformer. It works great, so it can be done!

If you are looking at some small Lincoln, Miller or other "name-brand" company you will probably do OK. But most likely, those welders will already have some type of provision for gas.