stall

After reading "hot and steamy Florida garage" post I wonder just how high the humidity can get before rust starts. I leave a unprotected piece of steel on the garage floor and so far there's no rust at 60%.

Any thoughts ??

Frankie the Fink

Rust is oxidation pure and simple....anything that supports that chemical reaction will increase its rate. Heat, salt, moisture (e.g. humidity) will take its toll eventually in the right amounts. I've seen brake rotors develop a thin coating of rust overnight in my garage before I could install them the next morning. I don't know if there is a specific "tipping point" for humidity when rust starts. Its probably a combination of many variables.

Tampa Jerry

As an ex-New Yorker, I can tell you that the salt on the roads causes more damage than high humidity here in FL. I drove my 68 coupe throughout many NY winters and it took its toll. My 66 was a CA car and had little to no rust. I keep the humidity down in both cars by putting a few desiccant bags inside each car. It cuts way down on the humidity inside the car. Where are you in FL? Jerry

bb62

Desiccant bags will help for all of 15 minutes. Once they are saturated, they give no more help. Desiccant bags only help if you have you car sealed in a bag where humidity cannot penetrate. Then they will absorb what humidity is in the bag.

oldsarge

I think that over a little time that piece of steel you have is going to show some rust. It doesn't take long for the humidity to take effect, but it might take a while for it to show. I have sanded down steel body panels to bare metal and come back in just a day and seen the result of the humidity. I have found that on bare metal, if you do not protect it right away, with some qiuck primer, you have to hit it again, before you can go on.