Rusty Cab Corners

[83dualtone]

Does anyone know why '80 model C10's commonly have rusty cab corners? I'm going to replace the sheet metal but was hoping to figure out how the water accumulates there so I can do some preventative maintenance before it happens again.
The truck is an '83 C10
Any info is appreciated.
Here's a couple of pics I took this morning:

[Blazin]

Its a tight spot between the inner, and outer cab corners. It is prone to rust because it gets dust and dirt built up over the years. That attracts moisture.

[83dualtone]

Thanks Blazin

[Engineer]

Also consider the fact that our trucks didn't have galvanized body panels.

When replacing the cab corners, rocker panels, floor boards, cab mounts, etc. you should consider stripping the black primer from the replacement parts then prime inside, and out with a good epoxy primer.

[hondarider188]

sorry i cant really contribute to the actual question but i have rust in the exact same place on my 83' k10. so would i need to order a cab corner or extended cab corner or is it something else?

[Donut]

Look and see how far the rust goes. 
Cab corners are 2 different sizes, sm and large depending how much you have to replace.  Also check the inner cab corner and rockers to see how bad they are.  Capt. should have everything you need.
I also have a couple to replace, just need time and a new welder first. (and of course $$ to do it)

[hondarider188]

im not sure on how far down the rust is on the cab corner. so if you have the specs. on the new corner replacements such as the length so i know which one i need. and i do think i need to replace my rocker panel anyway. i think i will start my one post on this so im not just taking up 83dueltone's thread. so please watch for it and get back to me.

[83dualtone]

Thanks guys. I did see the cab corner replacements. I'll definitely prime both sides before I weld them in.

[Remon.]

Its a tight spot between the inner, and outer cab corners. It is prone to rust because it gets dust and dirt built up over the years. That attracts moisture.

Ok. But where is the dust and dirt coming from? Should be from inside the cab right?

Also, the cap (on the backside of the cab corner, under the cab) is to high placed to get dirt and especially water out. I sprayed the inside of the cab corners with special hollow spaces wax, but it didn't come out anywhere. Not even out of the hole of the cap and I sprayed in a lot.

[Elpresidente]

I did mine 2 years ago, and i'll tell you don't bother with inner cab corners. Yes, they are supposed to keep water and dirt out of the cab (theres a small opening behind the seat behind the door jamb) but really all they do is create a terrible spot for rust. I cut mine off and left them out, welded up that opening behind the door jamb, and now I can clean that spot out frequently since its bad for collecting dirt.