Painting question?

[Changeling]

If this question is out of place, just send me in the right direction (not there).



I recently found out that a guy I know is a painter. We were discussing painting and he made a comment that left me somewhat apprehensive!

When I asked if he had a heat cabinet where he painted cars so they could be baked, he said it wasn`t necessary if you knew how to juggle the hardeners in the paint.



I was under the impression that a heat cabinet was necessary to paint cars so the finish could be baked. This was the only way a proper finish could be had.



Am I wrong, is the heat room no longer necessary for a first class paint job?



I am very well aware that great painting is an art and there are not that many great painters.



Changeling

[the other pc]

The paint is laid down and the painter has “done his thing� while the car is in the paint booth. This is where the shooter earns his keep. Baking comes after the fact.



Whether baking is necessary or not is determined by the chemistry of the finish system. Paint manufacturers know that not all of their customers have ovens so most re-spray systems are formulated to be either air dried or baked.



If you look at the oven schedules for re-spray systems you’ll find that the temperatures are very low. They must be, because re-sprays are performed on fully assembled cars full of rubber, plastics, paper, upholstery, liquids and highly volatile stuff like gasoline.



The baking they specify for re-sprays is really about getting the job out the door fast, not doing complete curing. It’ll reduce the wait time for more coats or to cut, sand and buff but you still need to wait many weeks for full cure.



So as long as your friend is following the manufacturer’s recommendations for air-drying he’s doing it right.





PC.

[Changeling]

[quote name=`the other pc`]The paint is laid down and the painter has “done his thing� while the car is in the paint booth. This is where the shooter earns his keep. Baking comes after the fact.



Whether baking is necessary or not is determined by the chemistry of the finish system. Paint manufacturers know that not all of their customers have ovens so most re-spray systems are formulated to be either air dried or baked.



If you look at the oven schedules for re-spray systems you’ll find that the temperatures are very low. They must be, because re-sprays are performed on fully assembled cars full of rubber, plastics, paper, upholstery, liquids and highly volatile stuff like gasoline.



The baking they specify for re-sprays is really about getting the job out the door fast, not doing complete curing. It’ll reduce the wait time for more coats or to cut, sand and buff but you still need to wait many weeks for full cure.



So as long as your friend is following the manufacturer’s recommendations for air-drying he’s doing it right."







PC, What you say makes sense, I guess I never considered any of the obstacles you brought up, thanks very much.



While we are on the subject then, besides Prep what is the most important consideration for a painter without a booth ?

Changeling

[the other pc]

Without a heated drying booth or without a spray booth?



Without a heated drying booth it comes down to following the directions for the paint system, using the right reducers and hardener, waiting the right time between coatings and for sanding and such.



Without a spray booth is tougher. A spray booth makes it much easier to work safely and avoid contamination in the finish.



Spray booths are designed to minimize the risk of fire while removing fumes and giving overspray paint particles somewhere to go. They also provide gobs of dust-free air and a generally clean environment.



When painting without a booth you either rig up that stuff or deal with the potential consequences. The last couple of garage jobs I’ve seen were full of embedded crap from the shooters not doing enough to keep the spray environment clean.





PC.

[Accumulator]

Changeling- FWIW the two painters I use are on eithe side of the baking thing- one does and one doesn`t. The guy who doesn`t turns out better work, both turn out properly cured by the time the outgassing period is over.



Per usual, the Other PC hit the nail on the head, especially about the embedded [crap] that can get in the paint and the two guys I use make for a perfect example.



IMO the most important consideration besides prep (and mixing the proper paint correctly, and spraying to correctly, etc.) is maintaining a clean work environment. The painter who *does* bake works at a dealership where the paint booth is in poor repair. The owner won`t shut the shop down and replace it and the resulting contamination is making life tough for the painters (and ticking off customers like me). The guy who doesn`t bake it works out of a shop that`s stone-age by comparison, but he keeps it operating-room-clean and it makes a big difference- *no* contamination, not a bit (though he does have to watch his technique as his ventilation system doesn`t handle the overspray issue quite as well as the fancy booth). Shooting paint without a proper spraybooth of any kind would be tough..so much potential for any number of problems.

[BobD]

The last painter I used sometimes baked and sometimes didn`t. I didn`t ask why though. LOL

[Changeling]

That explains everything I wanted to know. I appreciate the information.

I haven`t seen his paint area yet, I am pretty sure he uses a regular garage but what he does to it I don`t know.

Thanks, Changeling