Dry ice is the solid form of carbon dioxide. The carbon-dioxide particles sublimate under pressure, meaning it turns from a solid into a gas without first becoming a liquid when they hit the car’s surface.

It’s not the impact of the particles that removes dirt, cosmoline, rust, and other debris. The process of removing cosmoline happens when the carbon-dioxide particles turn back into gas.

Then, the cosmoline and other crud falls off the surface that is being treated.

 

I remember physics :-) My question is why remove the Cosmoline? I've actually gone through the trouble of respraying the coatings on several of my fun cars using the Wurth product..

 

Inadvertently, the cosmoline will be removed with all the other stuff. Then if you are worried about corrosion, you need to reapply cosmoline.

I guess some people like shiny aluminum, sans corrosion protection.

 

Some people do like shiny and some people don't have to worry about salt so risk is low. I actually brought that up in the video about treatment post cleaning.

 

Thanks for sharing your experience. I'm more convinced than ever that this is not for me. For my money I would do a thorough cleaning to remove built-up grime and grit and road goo, then follow with a protectant of some kind. Sort of like this Chemical Guys video.


Maybe some day people will look at the undercarriage finishes like they do the paint and interiors, i.e. "it's only original once".

EDIT: And the job he did on the wheels was kind of half assed IMESHO. I've gotten my wheels much cleaner with a good scrubbing followed by some polish and elbow grease. Not sure I'd risk the wheel finish with that gun.

 

Doing it by hand is a pain in the ***, but I was not willing to invest that much to have dry ice cleaning, so I have a sore butt and mostly clean undercarriage.

Dry ice s the way to go and if you are interested I would research the shop. This process creates a lot of blow-back residue and I would not want that infiltrating other parts of the car.

A good shop should know how to mitigate this stuff since it is such a health hazard for the operator, too.

 

A lot of info can be found here

https://cryodetail.com/

 

those wheels look great. Perhaps it was recording but they had 20 years of brake dust and filth all over them. That would have taken hours to accomplish.
As far as a DIY undercarriage cleaning… good luck with that. Take it from me, someone that has spent hours under my 911, cleaning upside down is a major PITA. You need a lift, pressure washer and lots of chemicals. Or you can do what I did and have someone blast it off with frozen CO2. Just about every crack and crevice is cleaned. Seth let me know that some of the blowoff might be found somewhere else but that’s the nature of the beast. I found a few spots and I just wiped it up.
My only regret is letting him use passivation on my exhaust. I kinda miss the golden color.

 

if you have the time and patience to be under the car for hours on end to clean it.....then go right ahead.

my time and health (breathing those chemicals and residue...god knows the long term effect) is worth more than spend a few hundred dollars to get it it brand new again.

no ones saying you should dry ice but let's not kid ourselves that hand cleaning is better or close to it. it's not.

 

I didn't mean it to be a disparaging post, my sincere apologies if it came off that way.

FWIW I have spent hours under my 996 cleaning stuff. But I have a lift.

 

I wouldn't do the whole underside, but I would not mind having all the suspension and aluminum cross member done,
It would look cool next to my brand new engine.. For a while.

FWIW, the dry ice alone for about 4 hours of blasting is almost 500 bucks, it has to be made by a special machine to make the pellets the correct size to feed the machine.
It actually does not work very well to get undercoating off, or grease. It takes the grime off, loose rust. Although it also depends on the pressure you run.

 

yup. i didnt do the whole underbody. i left all cosmoline alone. i wanted the engine/tranny, wheel wells and other suspension components neat.

 

Yeah nothing is cheap these days. As some of you know, my Florida rescue car was a complete basket case with rust drips, mud, road grime, sand, black widows, etc. It absolutely, positively needed it. It took him three days of off and on work to finish it and it’s still not perfect. But after all the work I’ve done to the body, engine and electronics it was worth it. It looks brand new.


At the very least I advise you to watch the last 30 seconds of my video where I do a side by side pan of the underbelly before and after.