advice re sandblasting

I'm a homeowner with two projects that, I think, would be greatly helped by sandblasting, but I can't find knowledgeable people in the rental stores. In fact, I only found one place that rents a sandblaster, and they tried to talk me out of it. So, I'm seeking knowledge and advice.
1. I want to epoxy the garage floor so I need to strip the floor of existing paint (or perhaps stain). While the paint is worn through in places, where it hasn't it appears firmly on. The last place I did this I tried a high pressure washer; it would cut under areas beginning to flake, but wouldn't cut through solid areas. (So I ended up grinding down the entire floor with a hand-held grinder-vac -- which I'll never do again.)
The nearest rental shotblaster appears to be 4 hours away and would require a truck, which I don't have. Only one place in my vicinity (Sarasota, FL) rents a sandblaster and they're trying to discourage me from renting it -- apparently because of the liability of customers dealing with silica-sand. Plus, it's quite expensive.
My questions:
1A. This sandblasting unit is on sale at my local Harbor Freight store: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?function=Search Would it do the job?
1B. Would 'playbox sand' from Home Depot be different than (less toxic than) silica-sand? (It's certainly cheaper.)
1C. Regardless, would playbox sand work? If so, what size tip/nozzle would I need for this?
1D. How much sand might be needed to do a large 2-car garage?
1E. Alternatively, there is a gizmo that appears to allow an abrasive (sand?) to be injected into the water stream of a pressure washer, which would help it to cut through paint. See here: http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeIdi70&productId20&R20 Would it work? Any gotcha's to it?
1F. Any other suggestions?
2. Next I need to clean a driveway as well as decorative stone facing, both with many coats of paint. (And I'm guessing the stone is fairly porous). Would any of the above answers in #1 differ for either the driveway or stone?
MANY, MANY thanks in advance for whatever help you can provide me.
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I suggest you rent a floor polishing machine and use abrasive discs with it. That should rough it up enough to paint.
There are too many issues with sandblasting for an inexperienced person to deal with. You need a tremendous volume of air. You must wear protective clothing and a respirator. You must prevent the sandblasted material from entering open air as the EPA considers this toxic pollution. You must dispose of the material as though it were toxic waste. Depending on how hard the surface is, sandblasting may alter the face from smooth to coarse.

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Roughing it up doesn't adequately prepare a surface to epoxy. Assume I'm willing to deal with the issues of clothing, respirator, and disposal, so I'm still looking for direct answers to my questions.
Thanks. _______________________

http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeIdi70&productId20&R20
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FWIW, Rather than grinding or sand blasting, rent a floor sander. Once the paint is off, dose the (concrete) floor with muriatic acid (be careful!) to prep it for epoxy paint. If there's lead in the paint, be sure to wear protective gear.
The little experience I have w. sand blasting taught me you need a big compressor. Perhaps the Northern device would work but be sure to determine what size pressure washer it requires to function correctly.
Don't know what to recommend for the irregular driveway. Perhaps paint stripper?
BobAtVandy wrote:

http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeIdi70&productId20&R20
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I agree 100% here.
I will add that I did sand blast a two and a half story building one time to remove the paint from the brick. I started with paint remover to actually remove the paint and used the sand blaster to clean it up removing the last little paint and many years of grime. I used a small home type sand blaster and rented a trailer mounted commercial compressor. I worked that large a compressor. It was a hard dirty job and took a couple of weeks. If I had a nice flat surface like a garage floor I would definitely use a floor sander.
--
Joseph Meehan

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Greetings,
I am sorry to hear so much negativity surrounding sandblasters. A sandblaster is a marvelous tool with almost magical productivity qualities. In my opinion, a sandblaster by far the quickest way to accomplish your task. You will easily spend more time in setup and tear-down than in actual paint removal. If you want cheap sand you can probably purchase it by the ton at a landscaping supply store for a fraction of the cost at Home Depot. You do not want "playground sand" because the edges of the sand may not be "sharp". You want construction sand made by grinding down rock. The problem is that the sand will probably be too moist. I always keep a supply of about 1000 lb of sand in my basement sitting around for months just in case I ever need some which is dry. You might also consider purchasing a product called "shredded glass" for the blaster instead of sand if you do decide to purchase official sand-blaster sand. Using a sand blaster is a lot of fun. The only thing I would caution you about is to not skimp on the compressor. I know I will probably get flamed for telling you that you can get away with construction sand but with the right compressor it will still perform a satisfactory job.
Hope this helps,
William
PS: If you do happen to get a curious kid as one of the other posters suggested just go over him again until you cannot tell.

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