I have my outback stored in an enclosed garage in DE during the summer. It's about to come out of its 3rd summer of storage, and spending time under it looking at the underbody I notice that surface rust on some but not all of the large steel components of the undercarriage (suspension arms, mounts, brackets, drivetrain parts) has increased over the summer. I also find white powder deposition on some parts that look like they're aluminum (transmission housing, can't remember what the part was but remember it had that dull gray look of aluminum).
This is disturbing because I don't want my darling rusting continually while I think that I'm giving it good care by storing it in a nice garage.
I think what's happening is:
- the garage is on the ground floor of the building, a poured pad
- in the summer, the garage gets quite warm (it's heated but not cooled)
- the air is humid all the time, with marine humidity because it's about 200 yards from a salt marsh and bay
- the car is on 3/4" boards (on tires) on a plastic sheet over the concrete floor
- I suspect that the relatively cool floor is creating a temperature gradient compared with the rest of the warm summer air in the garage, the metal undercarriage in this cooler environment gets condensation of the moist air in the garage, and particularly because it's marine air, rust and other surface corrosion form
solutions I've thought of, fall into two categories:
a coating for the underparts of the car.
- I see the body panels are already undercoated, I'm thinking of something to spray or brush onto the suspension members, drivetrain components and brackets, etc. that would seal the metal surface against the moist air.
-- I'd prefer not to have to do extensive surface prep first. Thus, something that converts the rust or at least stops it from expanding its activity would be preferred
-- if I can do it myself I will, otherwise I'm interested in commercial solutions where I pay someone to do it
-- if it needs to be reapplied each year because of abrasion, washoff etc. that's not a showstopper
a coating for the floor:
- I don't really think this will solve it because of my suspicion that the temperature gradient is the primary actor and the car is on a plastic sheet so that moisture transfer through the floor to the region of the car underbody shouldn't be significant. But if you disagree or have experience with a good solution, I'd like to hear about it
Solutions which aren't viable are to run A/C to the garage, or to run a dehumidifier in the garage. Weatherstripping the garage to decrease humidity is a low-likelihood maybe (because I suspect it won't work well enough to be worth it - again, if you disagree, glad to hear it.)
Thanks for any ideas...
This is disturbing because I don't want my darling rusting continually while I think that I'm giving it good care by storing it in a nice garage.
I think what's happening is:
- the garage is on the ground floor of the building, a poured pad
- in the summer, the garage gets quite warm (it's heated but not cooled)
- the air is humid all the time, with marine humidity because it's about 200 yards from a salt marsh and bay
- the car is on 3/4" boards (on tires) on a plastic sheet over the concrete floor
- I suspect that the relatively cool floor is creating a temperature gradient compared with the rest of the warm summer air in the garage, the metal undercarriage in this cooler environment gets condensation of the moist air in the garage, and particularly because it's marine air, rust and other surface corrosion form
solutions I've thought of, fall into two categories:
a coating for the underparts of the car.
- I see the body panels are already undercoated, I'm thinking of something to spray or brush onto the suspension members, drivetrain components and brackets, etc. that would seal the metal surface against the moist air.
-- I'd prefer not to have to do extensive surface prep first. Thus, something that converts the rust or at least stops it from expanding its activity would be preferred
-- if I can do it myself I will, otherwise I'm interested in commercial solutions where I pay someone to do it
-- if it needs to be reapplied each year because of abrasion, washoff etc. that's not a showstopper
a coating for the floor:
- I don't really think this will solve it because of my suspicion that the temperature gradient is the primary actor and the car is on a plastic sheet so that moisture transfer through the floor to the region of the car underbody shouldn't be significant. But if you disagree or have experience with a good solution, I'd like to hear about it
Solutions which aren't viable are to run A/C to the garage, or to run a dehumidifier in the garage. Weatherstripping the garage to decrease humidity is a low-likelihood maybe (because I suspect it won't work well enough to be worth it - again, if you disagree, glad to hear it.)
Thanks for any ideas...
