Outdoor storage and rust

tomgreevertomgreever Member Posts: 4
edited March 2014 in General
I have a classic car with some minor surface rust only, and one rusted out quarter panel. If I store this car outdoors under a tarp for 5 years (no time to restore it right now), will the rust get any worse if it is kept dry? In other words, does rust continue to grow even without moisture?

I would built a pole barn around it and then cover it with a tarp. So there's a chance that some moisture may get into it, but not much. Does rust only get worse if it's exposed to direct moisture?

I am wondering if I should get rid of the rust first, cover with primer, and then store it. I'm afraid I will worry about it outside too much unless I understand more about rust! Thanks...


  • texasestexases Member Posts: 9,700
    Yes, it'll get worse, there is always some moisture around. If you can remove the rust, do it. I've heard of folks coming back to their car after several years to a much worse condition than the one they left.
  • tomgreevertomgreever Member Posts: 4
    Right, that makes sense. So if I remove the rust, perhaps even apply a rust-away product, and then prime it... Does new rust form even without exposed metal and direct exposure to moisture?

    I guess I'm trying to figure out how cars rust in the first place. My guess it's mostly from a scratch down to the metal and then direct exposure to moisture. So I'm thinking if I make sure there is no exposed metal, then there's a good chance I won't find any new rust on it in 5 years. Am I thinking about it correctly?

    Because my other option is to put it in my garage, but I don't want to do that. At this point, I don't see much difference in building a small shed for it, versus putting it in my garage (in terms of exposure to elements).
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    You have another issue. If you cover a car, moisture will rise up from the ground, get trapped in the cover, and then when the sun comes out, it will "boil" the little droplets and created little pits in the paintwork. These in turn will turn into hundreds of little rusty pits all over the surface of the car.

    Covers are, ironically, the WORST thing for a car outdoors.

    Is this some rare kind of car that you couldn't ever find again? 5 years is a long time to sit on something and you may be better off just saving up some money the next five years and finding a cleaner example of what you like---especially if the car is not the type that appreciates very quickly (and most aren't these days).
  • texasestexases Member Posts: 9,700
    Rust is often call a 'cancer' for cars, it's hard to get rid of. While surface rust can start from a scratch like you said, the bad kind of rust (around fender wells and elsewhere with bubbled paint, etc.) starts from within, with poorly-designed bodies that collect water and dirt and debris. The paint breaks down and rust begins. Getting rid of it requires lots of work.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    The problem is that if the rust gets fairly deep, you can just bead-blast it. This merely covers the rust holes over, like peening with a hammer, and they will re-appear. With very rusty metal, you have to chemically dunk it. This has its own problems, because if you hot tank the frame, it's hard to get all the chemical out, and after you restore the frame, the chemical can seep out and ruin your work.
  • tomgreevertomgreever Member Posts: 4
    Yes, I have considered that about using a cover (that moisture gets trapped underneath). I think at this point I am going to build a sturdy enough "shed" for it, with a roof and walls but with no floor. And then I won't cover it with the tarp. And I will go ahead and get rid of the rust as best as I can for now. There's not too much.

    As for the car, yes it's fairly rare in the sense that I've been looking for a specific year and model for many years. They are often either too far away, completely rebuilt and expensive, or parts cars. I happened to find one 30 miles from my home that's the exact make/model and even the color I wanted, with everything in tact - it just needs to be rebuilt. So it's hard to pass up.

    Actually, the only reason I'm sitting on it is because I want my boys to be older to help me with it. I could conceivably do some of the body work myself now just to get it in better condition. And maybe I should even consider taking the body apart and storing the pieces in my garage.
  • andre1969andre1969 Member Posts: 24,645
    is to park the car on top of a plastic tarp or sheet. That will at least provide a barrier between the ground moisture and your car. You'll still have to deal with rain water that gets on top of the plastic, though, although that probably wouldn't be as bad as constant moisture from the ground. Plus, with the plastic tarp, any water that sits on top might evaporate quicker.

    As for covering the car, they do make breathable covers. They won't keep rain water off the car, but will help with dust, bird crap, etc.

    And if you end up building that shed to keep this car indoors, then in addition to putting down a plastic tarp, you might also want to put a few sheets of plywood down as well, to provide an extra barrier between your car and the ground.
  • explorerx4explorerx4 Central CTMember Posts: 16,289
    i think you need a floor in addition to the shed to prevent moisture from forming under the vehicle surfaces.
    i have a vehicle in my driveway (blacktop) that has been there for about 3 months.
    every once in a while, i check under the hood to make sure no little critters have started making nests under there.
    on a warm day, after a good amount of rain in previous days, i opened the hood (2 weeks since i last looked) and there was a bunch of moisture covering a lot of the areas of the engine bay.
    andre, i see you just posted something similar.
    2020 Ford Explorer XLT
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    You need a floor covering AND a small electric fan circulating air underneath.
  • explorerx4explorerx4 Central CTMember Posts: 16,289
    i'm going to start driving it in about 3 weeks, so it will be all set when my kid comes back from a semester in the land down under.
    2020 Ford Explorer XLT
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