rust behind battery?
 

found a pretty bad rust spot behind the battery... cut it out and weld? suggestions?

Year of car and pictures would help. Was it rust from battery acid or rust from crud piling up on the inside of the fender and rusting from the outside in?

Clean it up with a wire brush back to the edges of good paint. If it's just spot rust, cleaning and priming may be fine. Be sure to neutralize any remaining acid. If you have a hole, post pictures and see what the experts say.

http://i32.photobucket.com/albums/d1...01213-1423.jpg

1976 from the inside

You sure that is from the inside out? On at least the Carrera, there is a ledge up in that spot in the wheel wheel that collects dirt, which holds water, which creates rust. Either way you are looking at removing the fender and patching the inner fender. Not overly complicated, but is labor intensive.

From what little I can see, it looks fairly deep. Next step, clean it all away to shiny metal and post another picture.

took out some more stuff andIm beginning to think of replacing the front end. how difficult does everyone think replacing the front frame with a tube frame would be?

Hmmm... Hard to see for sure in that photo... it does look like it is higher up which suggests rust from crud built up on the topside of the bumper shock support which is in that area (as suggested above). A poster here, I think named Sailchief did a nice writeup on this.

The other major rust issue near the battery is suspension pan rot, caused by battery acid that leaked out at one time and was not properly dealt with. More common than many realize on these cars I believe. I had this problem and you can get a bit on an idea of how it went for me here:

Battery-area surprise! - Rennlist Discussion Forums

In either case, I think that you will find that the necessary replacement sheet metal is pretty reasonable and will be simpler and cheaper than doing tube frame front end.

what gauge steel would you suggest using for the sides?

I wouldnt worry about the guage of steel just yet. You need to get it all cleaned/cut out and then determine what you need....

Recent experience makes me think you might have rusted shock mounts, like me.

http://forums.pelicanparts.com/uploa...1292364389.jpg

From my thread here.

Yeah, that's a nice write-up (and repair) too!