my brother in law has a 'V' reg (99) Marea, its rusting to bits and is made from coke can guage metal, just blows through when you try to weld it even on the lowest of settings.
Yes, they are more rust resistant then previous models, but the problem is that not all of the body and chassis parts were galvanized. Also first models, (89 to about end of 90) are much more prone to rust then later (91 on).
On this particular car, whole rear joints of the boot floor and wheel arches were rusted trough, only thing keeping me from seeing that before was a lot of paint and under seal keeping the rust together. The car started to drive strange, rear end would keep on trying to escape off the road even with moderate driving, so I set to find the cause, and after removing everything from the boot, I found this:
Then I set out to repair it, but didn't have a mig yet, so after looking around settled on an einhell BT-GW150. After I was all set up, then it was on to work and some more work, and the result is there, what you can see for now. There is a lot of work left to do, I will update later. One curious thing I found is that my mig works best on about 60A, wire speed 0 or 75A, wire speed 1. It seems a bit odd to me that this tin foil requires so much amps to fuse and penetrate properly. The machine has 6 power settings (25, 43, 60, 75, 90 and 125 A), and wire speed can be regulated from 0 - 10 in 1 step increments. I am using 0.8 mm solid wire, ER70S-6 standard, and pure CO2 gas at about 11 to 13 lpm.
I have noticed it is much harder to get a nice burning of the wire with this machine then with it's much more expensive brand name counterparts I use at work, however with enough patience good results can be had. Or make that a fair sized bit of patience
It is but using .8mm can help on realy thin stuff as it increases the total amount of metal in the join so you get less blow through. Like welding thick to thin.
Today the left side was finally done, here you can see how it's done, also some attempts at closing a rear box (which has about 0.5 mm foil, nightmare to weld), not too pretty but should do the job:
Also the right side was started, first panels in place, rest to come in a few days:
It's not easy, looks that way, but I'll be glad once it's done and repaired. Positions to weld are sometimes near impossible to get to.
And we are finally done with rear arches, here is what we got at the end:
I am pretty satisfied with end result, it's been like 50 or so hrs welding, grinding and fitting in this seemingly small job. If anyone has questions, feel free to ask.