painting the car what heat should i use

I wouldnt use anything that burns, Anything that burns will have a residual from whatever fuel you are using. Thats just me and it maybe OK to use some of the mentioned form for heat but I wont do any of them. I used a kerosene heater to heat a garage once before I did any painting just to warm things up. The kerosene left a residue on everything and I had a lot of contamination issues.
I use electric now for my heat source.

I use a kerosene/diesel heater That I put outside near my air intake fans/filters so all of the air that comes in is heated. I can adjust the temp in the shop by the speed of the intake fans or the distance the heater is from the fans. I can keep the shop at 75*-78*F all day and night long when it's 20*F outside. I use diesel in the heater and have never had contamination issues.

Anything burning propane will put a ton of moisture into the shop. Water is a byproduct of propane.

Anything with a flame would scare me - particularly doing a whole car.

Ventilation is fine - but there goes your heat !

Why not look into renting a spray booth for a day or two and not worry about all those issues in your shop?

No open flames, period.

If you can heat the area up enough, then turn off the heat and spray, that would be fine. It's the exchaging of air that's probably going to quickly remove any heated air you will be able to accumulate.

Look into renting a spray booth. You'll be much happier with the end results since you can concentrate on spraying, and not on maintianing the temperature.

Paint fumes are very explosive. Yeah you might get lucky 5 or even 10 times but it's really not a smart thing to try. Rent a spray booth and you won't have to let us know how it turned out from the Hospital.

Sheldon

I serviced HVAC for a number of years

ANY salamander type device fired with ANY fuel generates large amounts of moisture.

ANY direct fired device of this nature is an explosion hazard. I simply cannot believe how many people seem to get away with this. It's only a matter of time.......

Even an electric furnace CAN be an explosion hazard, because of arcing in the controls, as well as the possibility that the elements may get hot enough to reach an ignition temperature.

(Think of some portable heaters you've seen--red hot elements)

I believe the ONLY safe heating device for a paint booth is:

Electric that has appropriate shielded elements, think in terms of your baseboard heater. HOWEVER the controls must be spark proof as well

Gas/Propane/ Oil that is in the form of a furnace type device with a HEAT EXCHANGER so that there is isolation from the combustion and paint booth.

Additionally, something like a furnace MUST be OUTSIDE the booth. An atmospheric burner, taking in polluted air into the burner, presents not only an explosion/ fire hazard, but.....

any chemicals in the air ALSO hasten the destruction of the heater.

I've worked on equipment in places like laundries (bleach and soap) beauty parlors--various chemicals, photo/ print type shops--all KINDS of chemicals, and ANY of these types of chemically laden environments are VERY hard on the equipment, because when you HEAT or BURN a chemical, it usually makes the reaction much more severe

The thing is, the explosion hazard does NOT only come from vapors like paint thinners, etc in the air. The hazard ALSO comes from the DUST hazard. Various kinds of dust are very explosive. (Google stuff like wheat explosions)

http://www.osh.dol.govt.nz/order/catalogue/archive/dustexplosions.pdf

I'm no expert on the electrical code, but paint booths are required to be wired in terms of exposion proof devices and fixtures

anything that burns, water is the by-product.

simple chemistry!

any type of "fuel oil" gasoline, diesel, kerosene, liquid propane, natural gas, even wood... the hydrogen (H) in the item that is burning combines with oxygen (O) in the air, and you get H2O -- Water. the Carbon in the stuff you are burning produces CO and CO2...carbon monoxide--poisionus, and carbon dioxide--what we exhale.

so yes, any propane, diesel, kersone type heater can produce lots of humidity. Unless, as mentioned, it uses a heat exchanger, and the damp, moist exhaust is vented outside, and the heat is kept inside...which is what most home furnaces do. which is why the air can be so dry.

knowing the explosive hazards created by spraying a large amount such as an entire car, i think I'd want to wait until the ambient air temps were above 60 degrees rather than risk blowing my shop up, or spending big bucks on all the explosion proof heaters.

small parts here and there, I wouldn't have a problem with though...so use the winter time to do your underbody, suspension parts!

I have a forced hot air furnace (Modine) in my garage, it blows very hot, dry air. My booth (seperate room) filters intake the air in the corner, it goes across the car, then out the fan. I crank it to about 80, and can usually get a whole coat on before I have to let it "catch up," the temp usually goes down very fast with the fan on. I never turn it off, but I do regulate fresh air in the room where the furnace is, by opening a window an inch or so. I close it to "catch up," then open it again when ready for the second coat. Works well, until the temp is below freezing, then I have to wait until Spring! I don't have a moisture problem, just the usual dust problems. But my furnace is a cocker! It came with the place, but the seller wanted to remove it when he sold the house. Nice try, but it was in the contract, lol!

wood burner stoke it up real good with old railroad ties. You'll be the talk of the town for years.

Man!!! ALL THESE EQUATIONS!!
I never studied Chemistry. All this stuff is confusing.

I painted a truck once during the winter, I used a kerosene heater for about 8 hours before painting the truck to warm the garage and metal. I then shut off the heater, wiped down the truck to prep the surface, then painted. When the painting was done I opened the doors to allow the fumes to exit for 2-3 minutes, then closed everything up and fired the heater again for another 24 hours to allow the paint to cure. The job came out good and the garage is still standing.

So you're saying you highly recommend ignoring all the warnings and go ahead and use a flamethrower ?!?!

I've used a tablesaw for years without a guard so I don't think anyone needs a guard.
I've used a grinder for years without safety goggles so I don't think anyone needs safety goggles.
I've never turned off the power when working on electrical outlets so I don't think anyone needs to turn off the power.
I've been in boats loads of times without a life preserver so I don't think anyone needs a life preserver.
Right !?!?!

Safety is for idiots.
heh heh heh heh.