One compartment door has small holes on the outside. They appear to be caused by corrosion, rather than impact. They do not go all the way through. The inside of the door is fine.

What could have caused the holes? What should I do to patch them?

Thanks.

That's a very common problem. When you say the corrosion doesn't go all the way through, I think what you're seeing is corrosion going through the outer aluminum panel, but not the inner sheet. There is styrofoam in the middle I'll bet.

I think the styrofoam was part of the problem, it may have kept moisture in the middle which promoted corrosion on the aluminum sheet. A fix will be to totally replace the outer sheet. You will need to disassemble and see how it was made or take to a sheet metal guy.

Somewhere on here there is a whole thread on compartment door replacement. Try a search.
These doors are 2 pieces of aluminum sheet wth a thin sheet if luan sandwiched between. Water gets in past all the rivits and soaks the luan and sets up a galvanic reaction that causes the outside aluminum sheet to corrode.
As time goes on we all face the problem. Temporary fix by filling and painting is just that. Replacing the door panel is a very big job. This outfit makes a product that would eliminate the problem.
Don

http://www.whitingdoor.com/

Pictures Please

I had Whiting Door Co make me replacement panels using aluminum honeycomb rather than the luan wood substrate. They made them in exact size of the doors (I replaced all the doors) for under $400. You remove the rivets on the piano hinge on the top and disconnect the gas cylinder that holds some of them up and remove the locks. Drill out the rivets and then carefully saw through two corners at the welds and remove the edge. You can then pull the loose edge off and gently spread the sides and pull out the panel. Slide in the new panel and have an aluminum welder re-attach the edge you removes, drill new rivet holes for the hinge (using sealed head rivets, all aluminum), drill out the locks holes and install the locks, remount and then paint. And you are done and it will never happen again.
The luan and open head rivets allowed water to enter, soak the wood and corrode from the inside out. Nothing will repair this but replacement.

Thanks for all the good advice on compartment doors. Tom, I will be back to you to learn more about working with Whiting if I decide to redo the doors.

Steve