Shop cleaning

then you can finally have the dust explosion they don't want to happen.

A smart-assed response, but likely correct in its prediction.

What *kind* of dust is a crucial question. Not so much because if non- flammable the air-compressor soln. is viable (it'll go all kinds of places you don't want), but to think about what kinds of pick-up methods are viable, and what apecial precautions may be necessary.

Dave Dave

You're sort of on the right track, but like the other comment said, you don't want to get it all airborne. Thing a scissors or boom lift to get a couple people up to the ceiling, one with a hose from the biggest shop vac you can get and the other with a brush and an air blow gun. Brush the bulk debris directly into the vacuum, and use the blow gun to free the remainder from the crevices.

I think vacuum is a better solution than blowing, because once you have it airborne, if you don't suck it up, it will just resettle somewhere else. The duct cleaning people (for residential HVAC ducts) use a 25HP engine-powered vacuum, usually with ~8" hoses. Failing that, a usual 2.5HP workshop dust collector (4"-6" hose) would probably do a reasonably good job. I would also take the appropriate precautions re: flammable materials and flash points, including potentially turning off electrical service to the building and definitely not running machinery other than dust collectors and other which are specifically designed for this purpose.

I do just this 1 or 2 times a year. the key is too pick a day with 30 mile winds. Mine is a metal shop and machine storage. if'n your a wood shop you're asking for a big boom.

place i used to work was one better. Cellulose acetate is a fine powder made from wood products and strong solvents. Dust gets everywhere, A small pop will shake the rafters and then you'll blow the roof off.

karl

That is a lotta dust. I have tried the high-pressure air and fans in a powder-coat paint facility, and it worked - - sorta. The particulate was fluffy enough to go out with the wind --- mostly. BTW, it took a LOT of wind, a couple of big air-movers from the diary-barn at the "in" door, and one inside the "out" to help it along.

But in the machine-shop, the hundred years' accumulation needed a BIG vacuum and a man-lift for the most part. Our accumulation was black as sin (foundry-sand with carbon and binders) varnished down in layers by a soaking with the mist of kerosene used for the weekly wash-down of the machines for years, when that sort of thing was in vogue.

Compresed air will help loosen all that remains after vacuuming, but you must be prepared for the air-borne crud to get in the very exact places which you MUST NOT ALLOW it to settle. Just one of the facts of nature, according to Murph. Words like "perplexing", "pernicious", "persistent", (and worse) were hurled about for days following either endeavor.

And yes, dadgummit ! I AM speaking from exprerience.

Flash

I'm lazy, and that would be my first thought. Trick is BIG fans to suck it out, analyzing flow so that you might have to have one fan blowing positive flow into the building. As per others, I wouldn't consider dirt accumulation explosive unless you've been working on a lot of corn or wheat. ;-) Besides that, shut down welding operations, pilot lights, etc, and common sense source of ignitions.

I would suggest some GOOD respirators, though, and not just those cheesy dollar paper masks.

Maybe rent a BIG Schramm compressor for the day?

Steve

Just rent a Giant Vac:

I wonder if you might be better off to encapsulate the dust in a layer of paint.

Seems to me if you were to drape off sections of the shop like they do when they do asbestos or mold abatement then you could spray several layers of thin latex paint on the ceiling and this would stick all the dust in place, and give you the added benefit of improving your lighting.

Doing this section by section you could more easily protect the machinery or materials either by draping them with drop cloths or moving them out of the section you were painting.

Most of the dust won't stay airborne long enough to get blown out of the building. Gravity is not your friend in this instance. Better to vacuum it up as soon as it's disturbed from its resting place with the compressed air or a bristle brush.

Many parking lot sweeping companies use industrial grade trucks

Contract with one of these companies, get a sufficient length of flexible suction hose (HVAC flex is probably adequate) and you're good to go! Someone mentioned the HVAC duct cleaning companies as a possibility - that'd work too.

Carla Football combines the two worst things about America: It is violence punctuated by committee meetings. George F. Will

"Tom Gardner" wrote in news:pJcJj.24$ snipped-for-privacy@nlpi070.nbdc.sbc.com:

Bad, Bad idea. Dust and lots of 3-ph power doesn't go well together. There are companies out there that do this for a living, and they can do it in sections so that you don't have to shut the whole plant down at one time. They have the equipment, expertise and insurance to do the job correctly and safely. We had our foundry done a couple of years ago.

One fire will do it ;)

Where I used to work we had a fire that just would not quit. Standing outside seeing flames coming out of the roof mounted ECV units for a couple hours was shear hell. As we all imagined our jobs gone forever.

Luckily it was confined to the ventilation ducts and most of it was spec'd by an engineer that was conservative in that he used heavy wall duct work. Very little of the plant equipment was damaged though we had to move and contain a hell of a lot of water that was mixed with oil from the forming press pits.

We were fiber converters taking wood fiber and impregnated cloth to make shelf panels and such for automobile makers.

It was amazing how damn fast the customers can send a tool collection team if they think their supply of parts is in jeopardy. We managed to dodge the bullet that night and get the place running by morning.

After that we had a local firm come in with a vacuum truck to vacuum the air handling ducts every 6 months.

I'd get some quotes from companies that do this for a living. After you have those numbers you can always consider what it would cost to have a guy up in a sky lift with a barrel vac to do cleaning 'in house'.

One thing though, the bill from the outside firm indicating they did the cleaning would serve as proof that cleaning was done on whatever schedule your risk insurer is now demanding.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

On Fri, 4 Apr 2008 00:02:40 -0700, with neither quill nor qualm, "Roger Shoaf" quickly quoth:

Your insurance company will double your rates for thinking that thought out loud, Roger.

-- Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity. -- George S. Patton

Tom,

Look for one of those companies that shows up with a super-pumper truck to clean out flooded basements and see if they do dry particulate (i.e. dust) removal too. If they do, that's the safest thing to do since you probably have 100% year old stuff up there you don't want down on your stuff or in the air.

I'd still cover everything with tarps on an off-day and have them do this...

Regards, Joe Agro, Jr. (800) 871-5022

I am not sure why that would be an issue with the insurance companies. If the fibers were bound in the paint , it should be no more of a flammability issue than paint on a clean surface. If I understand the chemistry correctly, then the problem with the layer of the dust is that there is a great deal of surface area to oxidize, and that creates a low explosive charge when it starts to burn. If however the dust was bonded into a layer of paint, there would be no exposed surface area, hence no explosive potential.

I saw a demonstration once where a 10 foot piece of culvert pipe was set on end and a lit candle was laced on the inside. A cup of flour was then tossed in the top of the pipe and the flout exploded in a big boom. It was then explained that the oxygen trapped in the surface of the flour causes the surface area of the flour particle to burn rapidly and as the flour particle is mostly surface area, it burns rapidly igniting its neighbors and creating the rapidly expanding gas (explosion).

The same is true for wood fiber, but if one was to make paper or particle board from the wood fiber it no longer can rapidly oxidize hence it just burns.

On Fri, 4 Apr 2008 09:40:18 -0700, with neither quill nor qualm, "Roger Shoaf" quickly quoth:

Your insurance agent would see that you're covering up a problem, not solving it safely, and would probably act accordingly by increasing your rate or terminating you. If you're acting like that with this problem, what others have you hidden, just waiting to bite them? I wouldn't want to insure you after hearing that. YMOV

Ayup. I've never seen it happen but have heard all sorts of stories.

-- Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity. -- George S. Patton

Just tell the inspectors that it's ok and there's no fire hazard. The dust is mostly a mixture of fine silica and blue asbestos.

Mark Rand (running) RTFM

Back in the early 1980's I've seen a similar, but much larger situation when the dust was a mixture of white and brown asbestos with pulverised coal that had accumulated over 25 years or so, being occasionally disturbed by high winds blowing off the external cladding.

Seeing the cleaners vacuuming dust was the biggest shock though - it wasn't even their total lack of respiratory protection, or the total lack of eye protection, or their out of date, heavily stickered and damaged head protection but more their method of access - walking straight out on a dusty, grimy and oily 1ft wide girder around 100ft above ground level....with no harness. It made me very dizzy, and I was watching from solid structures with handrails and solid floor grating.