On Tue, 02 Aug 2005 21:41:40 GMT, "Ivan Vegvary"
wrote:
"Eddie" wrote in message
. 176.62...

I want to sandblast some wrought iron patio furniture with my new
harbor freight sandblaster, but I can't find a respirator suited for
sandblasting. All the local hardware stores' respirators say
NO SANDBLASTING. even called a sandblasting supply house but the
only respirator they have is some type of injected air system that
costs almost $400! I'll be doing the blasting outdoors, if that
makes any difference.
What are you guys using for respirators?

Myself, I stick the item in my bead-blast cabinet, seal the door...

The whole reason they put that warning on the respirator package is
to insulate themselves from the lawsuits. Or at least, to try. It's
like the cardboard sun shades for your car windshield, with the lawyer
mandated "Remove Before Driving Car" printed on them.

If this is a true DIY job, I'd use a full respirator with the right
cartridges and pre-filters (not the cheaply molded dust mask type),
and then have the wind at your back and use a hood or balaclava to
make the dust work that much harder to get at the filters.

If you are paying someone else money to do this blasting work as an
employee, you'd better follow all the safety rules and supply all the
high-dollar safety equipment. Or it's guaranteed that someone will
(according to their attorney) "develop a nasty cough" and try coming
back and taking you to the cleaners later.

I was thinking of making my own air supply. I already have a sandblasting
hood made from combination canvas/rubber. I intend to use about 60 feet of
garden hose with air supplied by an old squirrel cage furnace fan. I will
have to build a plenum for the fan and hook up the hose with duct tape.
Assuming that I get positive pressure to the hood, AND, wear a cartridge
respirator underneath, I think I will be OK and save approx. $800.
Any thoughts from others?

Nice idea, but you need a more powerful fan and a larger hose.
Furnace blowers work fine when moving lots of air using big ducts, but
they won't push against much more than 0.5 inch of water backpressure,
and a garden hose won't flow very much at that pressure. You'll need
to work against at least 5" WC backpressure.

For a remote air supply, think a small regenerative or ring blower
or a vacuum-cleaner motor blower to get enough flow and pressure.
Bypass cooled motor, so you aren't breathing in ozone and trash from
the motor and brushes. And make sure the motor is getting enough
cooling air, especially if you enclose it for noise - it might need a
separate muffin fan and ventilation path.

You need something bigger than garden hose to get the proper
airflow, they make 1-1/2" and 2" spiral-reinforced hoses that would
work nicely. Search for 'transfer hose' or 'dry food hose', I would
suggest a version with a static ground wire - go look around at
McMaster pp195 196 197 for some ideas (MSCDirect is 'unavailable' as I
write this.)

Or to do it on the cheap, go the local Borg (Home Depot/Lowe's) and
get a new pool vacuum hose.

And box up your air supply system and put one of those respirator
filters on the air input. Won't do you much good to have a remote
air supply if that air is coming in contaminated...

-- Bruce --
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
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