My 72 chevelle is rusty but soon I'm going to be tearing it down to replace all rusty panels. My garage is heated but with a natural gas furnace. Problem is natural gas is very expensive so I can't run it 24/7. So my question is will running the furnace from time to time while working on the car accelerate more rusting or am I being paranoid? Also pertains to my 07 gmc sierra classic.

Any time the temps change drastic enough to cause condensation you can start rust.
My 69 has been stripped since this past fall and with using the heat I've not seen condesation so far. Sometimes it will and sometimes it won't. Really depends on mother nature and you.

RandyB

I just leave a regular light bulb on 24-7. Does it help? No idea, but it makes me feel better.

No more accleration of rust than if your car were sitting outside unsheltered and exposed to water and oxidation.
Me, I'd turn the heat on to work in the garage. Wish I had a heated garage.

At this point anything that is going to rust has already began rusting, unless you have some freshly ground on or blasted metal. It wont hurt a thing if you are going to be getting to it in the next year.

cool guys, thanks

My understanding is different. We talked about this at a recent club meeting and many believed that heating the garage just when you want to work on it, in fact does accelerate rust. It makes sense to me but im not sure how easy that would be to prove.

heating the gararage adds energy to the room, which raises the temp and keeps moisture in suspension. When the temp drops again down around the dew point the water in the air percipitates and becomes droplets. The same amount of moisture is in the air as before. (look at all those big words mom) anyway, if there is bare metal, the droplets will then begin oxidation there and be more noticable. Now using an open propane heater or other catalytic heater does add H2O to the air from the burning process.

I had my body sandblasted in May of 2005, I keep it in an unheated garage until I work on it which is about 3-5 nights a week during the winter. I still have a few areas unprimed since the sandblasting with no signs of rust. These areas probably still have not been touched with my fingers either.

On another note, a buddy of mine with a couple Mopars told me he keeps a 5gal bucket of rocksalt in his damp garage, see says it will eventually fill the bucket with water, sort of a primitive de-humidifier. I set one up a month of so ago,and havent seen any results. Has anyone ever heard of this or is he pulling my leg? Another thought I had was would the salt be enough to enhance the rusting process.

I'm not sure about the rock salt, but I use dehumidifier crystals with some success. I use mine in my camper and it collects a lot of moisture. I dont know the science behind it, but once the water is collected, it does not evaporate so it doesn't go back into the air. Figured that one out when I spilled some of the liquid on the garage floor and just let it to evaporate. A week later it was still there.

A product like http://www.drizair.com/ can be purchased for pretty cheap at boat or RV shops. I ended up buying some generic refill crystals instead of the Dri-zair ones because I'm cheap. Something like this is a MUST for RVs.

As for worrying about air moisture in my shop, my Camino is under a car tent in a back yard. Between the worst wind, rain and snow storms we've seen here in 50 years I haven't had a chance of keeping the car 'moisture free'...

Get a hygrometer and check the humidity. Under a certain level (think its 40% RH), you won't have any problems with rust, regardless of temperature. The relative humidity changes with the temperature, and as already stated, you can get run into problems with condensation if the temperature changes. As an example: My garage usually stays cool, like 65-70 degrees, so when I open the door on a hot and humid day I'll see condensation on the car within seconds. When I take it out in the driveway, it gets totally fogged up and has to sit in the sun for a while before I can even drive it.

I use the garage for woodworking as well, so I need to keep the humidity at a decent level. I have installed a dehumidifier to control this, and it does a great job at keeping the humidity down. A constant temperature helps too. One thing I have noticed is that before I installed it, it took about two days for things to dry when I was painting. Now it dries overnight. No more cracks or warping in the wood either. :thumbsup:

Here is a simple hint for a car that is stored and the engine won't be started for an extended period of time. On all V8 engines, with the engine stopped, there is always one cylinder where the intake and exhaust valves are both open. This allows air to exchange up the exhaust system and through that cylinder up into the carburator (or vice versa.) So that one cylinder can suffer extended exposure to moisture, condensation, etc. That is why a "frozen" engine usually has just one cylinder that is rusted.

Duct tape or plastic baggie on the ends of the exhaust pipes and sealing the air cleaner or carburator prevents this air exchange.

JIML82

Here is a simple hint for a car that is stored and the engine won't be started for an extended period of time. On all V8 engines, with the engine stopped, there is always one cylinder where the intake and exhaust valves are both open. This allows air to exchange up the exhaust system and through that cylinder up into the carburator (or vice versa.) So that one cylinder can suffer extended exposure to moisture, condensation, etc. That is why a "frozen" engine usually has just one cylinder that is rusted.

Duct tape or plastic baggie on the ends of the exhaust pipes and sealing the air cleaner or carburator prevents this air exchange.

JIML82


I like that idea! Now, should I use Hefty or Glad? :O)


Honestly, that's a good tip!


Don

'70 Fanatic

My first car was a 66 chevelle droptop when I was 14, My dad was helping me restore it, but before it was completed I had to sell it to go to collage. 2 years ago I had to help clean out my dads garage after he past and found the 66 front filler panel that was stripped to bare metal back 23 years ago and had no rust of any kind on it. The garage had a kerosene heater that was used very little.

I just leave a regular light bulb on 24-7. Does it help? No idea, but it makes me feel better.

Will help keep the theives away thats about it. JMO

My first car was a 66 chevelle droptop when I was 14, My dad was helping me restore it, but before it was completed I had to sell it to go to collage. 2 years ago I had to help clean out my dads garage after he past and found the 66 front filler panel that was stripped to bare metal back 23 years ago and had no rust of any kind on it. The garage had a kerosene heater that was used very little.


If the garage is tight and your in a fairly dry climate... and the floor stays dry with temp change I would not worry to much! Temps changes with lots of moisture and rain type situations some get in springtime and summer humidity that cause moisture to form on the floor or other stuff in the garage then you could have a small problem... running a small fan may help some and be cheaper that running the heater for some of us poorer folk like me...better than it being outside in the rain thats for sure.

JMO And I agree with this post unless you have a real high dollar car and cant sleep at night without running the heat and worring about the humidity problems that cause rust:D

Yes your correct, it may be different in the south where there is more humidty. This was in lower Michigan.

But on another note I had one of my chevelle project stored in my enclosed trailer through the winter last year which was a bad mistake. I had rust all over the new shocks, chrome valve covers etc etc. when I pulled it out in the spring. So I would have to think a pole building style building (metal)would accelerate rust faster if its not insulate. JMO

Yes your correct, it may be different in the south where there is more humidty. This was in lower Michigan.

But on another note I had one of my chevelle project stored in my enclosed trailer through the winter last year which was a bad mistake. I had rust all over the new shocks, chrome valve covers etc etc. when I pulled it out in the spring. So I would have to think a pole building style building (metal)would accelerate rust faster if its not insulate. JMO

Garage or trailer would need to have good to great venting with good air movement also! I suspect the trailer was not vented very well if at all with lots of heat buildup and cool down at night.?
Good post here... I and others here will know not to store our prized belongings in a not very well vented trailer or garage for very long! I store several cars in a well vented non heated and not very well insulated garage year around and have for several years with little to really no noticeable trouble...and I do have some chrome. Again as I said before my cars are not $50,000 cars either.
Thanks

My 72 chevelle is rusty but soon I'm going to be tearing it down to replace all rusty panels. My garage is heated but with a natural gas furnace. Problem is natural gas is very expensive so I can't run it 24/7. So my question is will running the furnace from time to time while working on the car accelerate more rusting or am I being paranoid? Also pertains to my 07 gmc sierra classic.

If your garage floor was done correctly a layer of plastic was put down on the ground before the pad was poured, to prevent moisture from passing thru the concrete. You should not have a problem.
I've got a project car sitting in my unheated garage now for 5 years. The places where I was working down to bare metal have not rusted yet. The only heat I have is the black roof, a portable kerosene heater, a small frig for drinks and grease, and a small chest type freezer. Here in the SC humidity is abundant with lakes and rivers everywhere. For my show cars which are covered all the time I have big packets of desiccant material to adsorb the moisture. Once a year I put them on a cookie sheet and bake them in the oven over night to dry as package instruction say to bake at 275 for 10 hours.

Last night when I was out in the garage the radio said it was going down to -37C which is about -42F. I know when the temp gets that low humidity is usually around 15 to 25 %. This tells me that there is little chance of the air holding moisture, moisture is what causes rust.

I usually keep my working garage around 60 - 65F which is a good working temp. Turn the heat down to 40F when I'm not using it. I have Natural gas. I always leave a ceiling fan moving air around inside the garage. I make sure to kick the snow off my boots before coming in and when wet sanding cars, I make sure any water has dried before turning down the heat. In extremely cold weather, I moniter humidity by checking for frost on the side rails of the overhead door and the metal man door edges. When I'm making lots of air with the compressor for sandblasting or running air tools like drills or grinders, I check for water amounts when I bleed the tanks off when I'm done for the day and note how much water drains out. On cold days, very little. Frosty days, a little more. Warm rainy summer days produces the most moisture where i have to drain off a pint or so from a 100 gal air tank.

In my cold storage garage, I keep ceiling fan constantly going winter and summer. I also have a louvered exhaust fan that blows out unwanted air. I just regulate when I want it to blow out that. I am installing a humistat, which measures humidity and will control the on/off function of the fan. The only problem with this set up is monitering the incoming air for humidity content. When I control the exhaust fan myself, I would turn it off on humid or rainy days and rely on the circulation of the overhead fans to prevent condensation on my cars and parts. If I install a humistat, it will just tell the exhaust fan to turn on because of the humidity level, but the fan would also draw in more humidity from the outside air into the garage. See the problem?

I looked around and found a product called Rust Chek. You can spray this on bare or painted metal (won't harm the surface) and it will set up a layer to keep moisture off the metal. You can power wash it to remove most of the film it leaves behind. You could use WD40 in a pinch. Don't know if it would work for disc brake rotors. Anyone have an ideas?

Hope this helps you.

If your garage floor was done correctly a layer of plastic was put down on the ground before the pad was poured, to prevent moisture from passing thru the concrete. You should not have a problem.


I've heard about a layer of plastic helping with concrete.

What about if you don't think a plastic layer is IN the concrete? Would it be helpful to lay one down in the Fall and drive the car in the garage (on top of it) to help with moisture while it sits during the winter?

Don

'70 Fanatic

^^^like this?..i had a leftover roll of whatever this is called and thought i,d put it to use..
http://i4.photobucket.com/albums/y113/nounou1/DSCF1150.jpg

I've heard about a layer of plastic helping with concrete.

What about if you don't think a plastic layer is IN the concrete? Would it be helpful to lay one down in the Fall and drive the car in the garage (on top of it) to help with moisture while it sits during the winter?

Don

'70 Fanatic
The plastic layer should have been between the ground and the concrete.
IMHO it would depend on the size of the garage and how well the doors seal. A single car maybe two car no. In SC it would not help me parking on plastic I get my cars out all winter. Working on them with the plastic would be a big pain.
Part of the key to moister control is air movement. I have a 3 bay garage 30' x 40'. 1 bay is walled off and has a ceiling of plywood, for a storage room, for car parts, clothes in boxes, Christmas stuff etc. I simple put a 20" box fan, on a t- stat, to turn the fan on and off at 70*. It is mounted in the ceiling of the space. Everything in that room is fine no rust, or mildue. I keep the room baited for mice and use moth cakes for everything eles and I think the moth cake smell helps keep the mice down.

Plastic won't really help much, unless you cover the whole floor. The humidity in the air is what makes the rust form, and I really don't think it will do much good to just cover a patch under the car.

If you do indeed have moisture coming up from the concrete and you cover it with plastic, you're going to trap the moisture under it and you will more than likely get mildew problems (depending on temperature). If the floor is clean and unpainted, you could possibly use a sealer on it, but I believe it's better and easier to use a dehumidifier. That way you're able to control the humidity, regardless of where it's coming from.