Replies

1. 
   davidmeiland | Apr 20, 2005 05:40am | #1

   I don't know anything about that particular piece of gear, but I can tell you that bottled breathing air for firefighters does not come from an ordinary compressor, partly due to potential contamination issues and partly due to the pressures required. I would talk to the manufacturer of the unit and see what the standard setup is. I'm guessing that in an auto painting situation there would be a special supply source, not the shop compressor.

2. 
   gordzco | Apr 20, 2005 06:01am | #2

   A google on the subject turned up alot of information.

   Breathing (grade "D"air) compressors are not the same as your run of the mill compressors.

   http://www.airsystems.cc/product_pages/compressors/portable_breathing_air_compressors.htm

   Guess thats why we don't see scuba divers filling up their tanks at the gas station before heading out to the lake.

   Another site mentioned something about liquid water in the tank, very bad.

1. 
   Novy | Apr 21, 2005 05:41am | #4

   "Guess thats why we don't see scuba divers filling up their tanks at the gas station before heading out to the lake."

   Ummmmmmm Gord You don't live on a lake anymore ? 

   On a hill by the harbour

1. 
   gordzco | Apr 21, 2005 06:41am | #7

   It looks like a lake

   except for low tide

   and the Navy.

2. 
   DaveRicheson | Apr 21, 2005 01:12pm | #8

   Both you and Luka hit two biggies on air compressor supply air.

   SCUBA air is absolutly dry. Breathing compressed air laden wit moisture would be inviting all manner of lung infections. Who knows what kind of nasties are growing inside that compressor storage tank, not to mention  the rust and scale that is also present.

   The second issue is regulating the aip pressure down to 14.7 psi (1 atmosphere). SCUBA tanks use two regulators to accomplish the task. The tanks first stage regulator steps the pressure down from 3,000 psi (80cu. ft. alum. tank) to 150 psi ambient pressure. The second stage regulator, held in the month, adjust the pressure to ambient pressure for breathing at what ever your depth. At 30 feet (salt water) that secondary pressure is 2 atm, or roughly 28-29 psi.

   I am not familiar with the type of gear Fonzie is talking about, but my gues would be that it requires a very low pressure and highly filtered air source. The health hazards created by not having the proper air supply configuration, control, and filtering would most likely be too expensive for a small shop operation.

   IMHO, I wouldn't risk my health, just because I got a free piece of equipment.

    

   Dave

1. 
   Fonzie | Apr 21, 2005 03:18pm | #9

   Thanks guys, I didn't think of that water in the tank - didn't know most of this.

1. 
   gordzco | Apr 21, 2005 03:49pm | #10

   I was talking to a guy last night who told his story of a fungal lung infection a few years ago. It was a very slow progression over months from not feeling too good to having trouble catching his breath on stairs. His doctor mis-diagnosed, and prescribed pennicillin which blossomed the infection and had he not received prompt medical intervention, he could have suffocated.

   Could we say he was breathing spores through a supply hose?

   He smoked mushrooms.

3. 
   PaulC | Apr 21, 2005 04:36am | #3

   a couple of companies make filter systems (often built into pelican type waterproof cases) which remove impurities from the air to bring it up to breathing grade. the filters have service life indicators and the unit has a carbon monoxide sensor built in. i've used them, but they're not cheap, there are some strict maintenance requirements, and it still has to be good air going in.

4. 
   ponytl | Apr 21, 2005 06:16am | #5

   the deal on my sandblaster set up (3m or bullard) to get supply air... it uses compressed air (same air that goes to the blaster) to pull in outside fresh air that it then supplies to the helmet... not sure how it works but i know when it's 120 outside i'm cool covered up in that "outfit"  it's still filtered and no i have no idea how it works but i like it...

   pony

5. 
   Luka | Apr 21, 2005 06:26am | #6

   Any reason why you can't rig up a new shop vac ?

   Or a squirrel-cage fan...

   Just a matter of porting up or down from a squirrel-cage fan. I've got one that would probably come pretty close to already fitting. Taken from a wood burning stove.

   Mount it up in a solid frame, hook up a washing machine motor, and the thing would likely blow the mask right off yer face if it doesn't have regulation.

   ; )

   Regulation can be as simple as a piece of that solid pipe from a vacumm hose, that has a sliding aperture. The farther open, the less pressure reaches you, cause it's blowing out the hole. Close the slider, and you get full pressure...

   A person with no sense of humor about themselves, has no sense at all.