>Has any one heard of "Frozen CO2 Blasting" for paint removal??
>Many tnx
>Terry
Terry,
I am familiar with this technique. It uses pellets of dry ice (frozen CO2)
propelled by air pressure through a nozzle to strip paint. It can strip paint
from aircraft without the need to mask the canopy or other sensitive parts.
The beuty of the process is that the CO2 sublimes to gas and all you are left
with is paint chips to dispose of as hazardous rather than a lot of blasting
media mixed with paint chips that must all be disposed of as hazardous waste.
There are (were?) two companies that make systems, Alpheus and Cold Jet. Two
people here attended a demo at a Naval Air Station in 1990. One system worked
well, the other did't seem to work very well, but I don't remember which one.
The drawback is that the systems were very expensive ($75-100K) and required
large air compressors (290 psi, 850 CFM) and lots of CO2 (360-2900 lbs/hr).
It's definitely not for the home shop. One of the companies had a much smaller
version, but I think it was still pretty expensive and I don't know if it would
be big enough for anything other than small scale parts cleaning. I have the
data somewhere if you are interested.
Another form of CO2 used for cleaning is CO2 Snow. This uses a tank of
compressed liquid CO2 which allowed to rapidly expand through a nozzle. This
creates tiny "snow flakes" which can clean particulate contamination off a
surface through momemtum transfer. We use it routinely here as a replacement
for solvent power spraying for precision cleaning. It is non-abrasive, and
works well. It also can remove thin films of organic contaminants.
Let me know if you are interested and I can provide further details.
John Giles
jegiles@space.honeywell.com
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