Dry ice blasting a chassis - GIF

[piper184]

It is my understanding that the pellet size is controlled during manufacture of the dry ice. It has to be kept cold (of course) and it has to be kept sealed from outside air as any moisture in the air that comes int contact with the dry ice will condense and then freeze, sticking the pellets of dry ice together. This causes problems with the flow through the blaster.

The demo that was recently posted showed the blaster machine also having a cooling unit as part of it. I think that was for keeping the air dry so it wouldn't plug up the system. If I remember right, the person in the video was cleaning the underside of a car and it took several hundred dollars of dry ice to do the job.

[hemmjo]

Will they be outlawing that soon due to CO2 emissions. ??

[fizzloid]

There is a company not far from where I live in Germany that makes these dry ice blasting machines, I got a demo of one once for my company. They poured large bags of dry ice into the spray machine, it came out the nozzle as a very high speed powder which disappeared almost immediately.
Works great, I watched it strip some pretty heavy rust, dirt and old paint etc.from some old farm trailers and ploughs they used for the demo. There was very little residue or mess to clear up afterwards, really only rust flakes and dust. Dry ice is not too expensive, and easier to haul around than heavy CO2 tanks for smaller jobs.

[nova_robotics]

They poured large bags of dry ice into the spray machine, it came out the nozzle as a very high speed powder which disappeared almost immediately.

That's similar to what I'm used to seeing. Big blue plastic boxes arrive on site, approximately 1 x 1 x 1 m (or maybe a bit bigger), and they're filled with chunks of CO2. The chunks are maybe the size of "B" gravel. The dry ice blasting machine does the rest.