Question for the Welders

[MAK]

I finished stripping my front fenders, front valence and what I thought was a rust free hood this weekend. Unfortunately I found some rust coming through from the back side. I was going to use this hood because the one that's on my truck now has some rust along the lower side edge that I thought I was going to avoid fixing... Anyway, as you can see from the pic, it's got the swiss cheese thing going right at the front lip. I took a punch and forced it in each hole to enlarge them back to thicker metal. http://onlinecache.com/F100/slides/IMG_8692.html
I had a similar patch of rust on the driver side fender that I tried to repair with a couple tiny plugs and some nail heads. However, I kept blowing out around the welds in what I thought was decent metal. I guess the rusted thinner metal gets hot from the weld and disintegrates. I was eventually able to getn it all filled in but it would have been faster to cut out a big section to begin with.
My question is this. With my poor welding skills, should I attempt to fill-in the holes like I did with the fender or should I cut back a larger section of the front of the hood and try to do a single patch panel? Could or would a better welder be able to just fill in those holes or is the metal behind to rusty to fool with doing that?
Thanks for any advice.
Mark

[67mann]

I weld,but I'm not a day in day out welder.I would think if you have rust issue--1. the metal not strong enough to a good weld and if you do get it to weld --how longs it gonna last? 2.After ya fill the holes,you'll be grinding them smooth and if the metals week--your just gonna burn more holes through. Might save alot of aggrevation by using a patch

[MAK]

Yeah, I guess you're right. I should cut a section out and replace. I've seen guys before talking about filling in the holes but when you can't get to the backside to see how extensive the rust is or get it protected it will probably just come right back through around the spots you just filled. That seems like an odd place to rust I can't figure out how it would even get and stay wet in that area.

[4th effie n counting]

someone else had posted you can run a torch over the area, and any rusty areas should just disintegrate, then you could square it off and weld in your patch.
When i get my welder i'm going to pick up a fender or 2 just to practice the light metal welding. I haven't touched a welder in like 12 yrs. When i did do my little bit of welding it was mostly channel iron and angle iron, no sheet metal, so i need some practice so i can buy floorpans

[MAK]

someone else had posted you can run a torch over the area, and any rusty areas should just disintegrate, then you could square it off and weld in your patch.

That's a good tip. I'll bet it would work since that is what seemed to be happening by welding in proximity to the bad areas. I'll give that a try with the oxy-acetelyn torch and post back if it works or not. Thanks

[67mann]

effie---ain't teelin ya your business,but when you do--you'll have better luck---tack first(all around your patch)and when you weld continous---go 3/4" in different areas as opposed to the continous weld that you used on
the heavier gauge. This will help you from warping sheet metal or distorting it. FYI---in case you didn't already know