I have a 91 blazer with the normal floorboard rust. I have a little century 110 wire feed welder with no gas. I just use flux core wire. I can weld fairly decent with it on thicker stuff, but when it comes to the floor, it just burns through. Right now , I'm just practicing by patching up the holes, but soon I want to buy some replacement floor pans for it and do it right. I have new rockers ready to put in, but don't want to burn them up. Please don't tell me it's because I have a cheap welder, I know, it was free. Any hints or suggestions would be great. Thanks in advance.