roof rust

[ngarman123]

it looks like my roof is rusted through!!! i saw some bubbling on the inside so i got on top to investigate and sure as s*it! looks like i am going to be cutting out part of my roof and replacing it. couple questions though:
 is this a common area? its right in the middle toward the back 1/2 of the cab.
 should i just buy some sheet metal and cut a patch or find a donor cab and cut a hole in that roof for a patch panel.
 my truck has never had a headliner since i have owned the truck so will i have to weld the inside also and smooth it down so you do not see my patch panel?
 any tips trick tips? if you could not tell i have not patched panels before. thanks!!

[ccz145a]

However you do it, the roof is double walled, so it won't show from inside.

[jaredts]

I don't know how bad the rust is, but you should be able to make it from a flat piece of steel (as long as your patch is less than about 6" x 6").  Before you cut anything bend and tweak the patch until it sits perfectly and conforms to the curvature of the roof.  Then scribe all around the patch and cut right on the line.  Butt weld the piece in, grind, and add body filler.  Can you weld?  I think this could be done with panel adhesive if you had to, but wouldn't be my first choice.  Mine's not rusted through, but my roof also has some surface rust.  The sun beats down on it and destroys the paint.  I don't know specifically about these trucks but roofs can be a problem area on any vehicle.

[ngarman123]

jaredts: i am not sure how big my patch panel is going to be i need to get it to bare metal and really assess the damage. i am a welder by trait but not this type of welding so i have all the stuff to do it but just not alot of experience doing body work. most of the time i am welding under a microscope so mig welding a panel in is way out of the norm to me. also how thick is typically sheet metal on these trucks? what type of body filler do you guys like? just regular bondo brand or a different type? just wondering thanks!!

[jaredts]

The steel is somewhere around 18 gage (.05").  I'll be honest, I have used cheap plastic body filler the most.  It can shrink, so I'm not sure I recommend it.  Usually don't have any trouble.  I have used Bondo brand--its not too bad.  You need to practice if you haven't welded sheet metal much.  It takes a very careful touch to not burn through.  You can do this--its not that hard.