I have a 94 extended cab short bed with rust in the typical areas lower cab corners and rear fender wheels what would be the cheapest way to fix this bondo maybe if so any techiniques?

 

If you don't cut out all the rust it will come back, then weld in new metal. It's not good to cheap out on body work.

 

sean is right your best bet is to fix the rust buy replacement panels and weld them in but if your just looking to get by a few more years for what ever reason sand the rust as far as posible spray anti coroseve materials like you can pick up in a homedepot or lowes comes in a spray can and it helps slow the oxidation proces down then use the bondo to fill in the imperfections block sand and spray your primer base and clear

 

As I'm working on a tight budget are these panels fairly affordable and the work?

 

I think the patch panels are fairly cheap, but I haven't priced them myself. As compared to other panels I've priced they should be pretty cheap. For comparison I need the entire quarter panel for my LeMans and I found them for $200 each, plus shipping. Smaller parts I need are lower, like the trunk drops are around $50. For my wheel wells I was going to get front fenders from the junkyard and patch the bed sides with them. They would need to be welded in, and I'm not sure what a shop would charge to do that. It would be cheaper if you had them weld it and you finished the bondo. If you have a friend with a welder maybe they could help or let you borrow their machine. You could see if someone rents welders. If you can't weld or never have you can practice on scrap first so you don't mess up the truck. Then when you do the truck cut the patch area smaller than the patch panel you get, and if you mess it up you can get another panel and try again.

Or, if you want to be cheap (I've done it) after cutting out the rust use fiberglass cloth and fiberglass bondo to fill the hole. You will tap the outer edge of the hole in some so you can lay the cloth on the surface without it sticking past too far. You don't have to cut out any rust that hasn't made a hole through the metal unless you can't sand all the rust off. Every trace must be removed. Using an epoxy primer also guards against future rust.

 

Try the local schools. Any high school or community college with a body shop program is always looking for test vehicles. They will be graded on this work so they really want to do it right. Most of the schools will do the work for a nominal fee

 

grind the rust out with a grinder then get the chemical treatment that turns rust to zinc and treat the rusted areas this used to be called Navel Jelly...Oxysolve was another one..then once it is treated you can fill it in..I have riveted metal as a backer and bondo or fiber glassed in stuff...as long as you treat the rust it would be fine...for larger stuff it is better to replace teh panels...

 

I just redid my 1992, the easiest way to fix the box is just to get a used box with no rust, although it can be pricey. As for the fender i grinded out the rust treated it and used marglass to fill, but mine werent too bad. If they are you can get remake front fenders for about 80-100 bucks a piece.