SAND BLASTERS

[jeffb]

Wondering if any of you could offer some insight into sand blasters.  appears they can be as simple as hand held, no doubt slow but perhaps useable?  any suggestions?  thanks jeffb in sd

[mrman5917]

I have one of the small open-air models from harbor freight that I use on the smaller parts. My air compressor doesn't have enough horsepower to keep up for constant usage, but as long as I take frequent enough breaks to let it build back up I'm all good. I've done brake backing plates, rear axle, small plates and covers, etc. My only real complaint is that the valves they ship for the bottom of the canister and the nozzle are prone to wear fairly quickly when using the stronger abrasives. I'm on my third nozzle and need to replace the lower valve too. For a cheap blaster it works well.

[F Bill]

Jeff what are you trying to accomplish? THe shop I used to work in had a spot blaster, big old combination vac and sandblaster in one that could be used on small rust spots.....ALso had my own small handheld blaster that looked kinda like a spray gun but with a bigger nozzle....both could be used in short bursts inside without mega mess, anything more than a couple of quarter sized spots and it would be outside to the sand pit, where a pressurized blaster (HF has 'em for less than $100 on sale often) would be used with large quantities of air and sand. That would be to blast entire panels, chassis, wheels, etc.

In any case take the safety part seriously. Silica sand is nasty stuff when you continually get exposed to its dust.

Check out TIP sandblasting on the web, Truman Industrial Products is their name originally, they will send you a nice catalog for the asking that answers more blasting questions than you knew to ask.

Oh yeah.. every blaster needs a BIG air compressor to do anything major with it. Of course BIG is a relative term.

[Gunslinger]

Let me expound on BIG for a minute, the key is how much CFM you need.  The sandblaster will tell you what the consumption rate is, and the air compressor will tell you what it can produce.  The key is the air compressor data is in "Standard Air".  Standard air is 70 degrees farenheit at sea level.  So you have to increase the size of the air compressor for elevation and for temperature.  This is true with air tools as well.  Humidity also affects the rate that the air compressor really works at because water takes up space in a cubic foot of air, when compressed it drops out so you need more uncompressed air on a humid day than on a dry day to have the same amount of useable compressed air.  Bottom line, its a good idea to over size your air compressor by roughly 25%.  Just like a lot of things, there is no replacement for displacement.

[jeffb]

thanks for all your comments.  i have the tub off my 51 and plan on doing most myself and not in a hurry therefore thought i might purchase a small sandblaster and do necessary work.  i know what you are sayig about compressor sizes and i am actually just waiting for mine to burn up so i can buy a new one!  appreciate all your knowledge  jeffb in sd

[philshevlin]

Sorry to jump in, b ut I'm at the same point. �Would this be decent for a tub?

http://www.harborfreight.com/40-lb-pressurized-abrasive-blaster-34202.html

Or do you need bigger, like...

http://www.harborfreight.com/110-lb-pressurized-abrasive-blaster-95014.html (edited)

[F Bill]

Phil your links are both to the 40 lb pressure pot......I have one , haven't tried it yet (i bought it a few days before we turned off the electricty at the shop) but it is actually a step up from one I used for years made from a freon bottle. The nozzle is one key to its performance...you want to have a nozzle only as large as you need to keep from clogging with whatever abrasive you use. Too large and you go thru sand and air like crazy, and the effectiveness of the blaster drops.....With only a 40 lb capacity you have to keep refilling but beleive me the break will be welcome.

I prefer the large conical ceramic nozzles and usually buy as small as they come.. I will use them for sheet metal, small parts etc, and they wear larger as  you send bags of sand thru them. For chassis blasting with an adequate air supply, these worn nozzles get the job done quicker.

HF includes a joke of a sandblast hood, expect it to last for about an hour and not really protect you much. You will want to purchase a real hood with a glass lens, that has a replaceable lens protector.  A bud of mine found a source for convertible top window material, and cut his own blast hood lenses from it, and it cost pennies a lens. Beats trying to save a $$$ lens and not really being able to see what you are working on.

Real sandblast hose has a ground wire in it. Some of the cheaper units have no ground wire andstatic electricity builds up in the hose to the point that it will make a painful shock  to exposed skin once it can establish a circuit. If you keep on getting zapped, especially on bone dry days, look at making a ground path from the nozzle to the canister to ground.

[philshevlin]

Thanks.  I corrected my link.

I was curious about the protective hood/clothing as well.  

What media do you suggest?  

[F Bill]

A good hood, full coveralls, a good cartridge respirator or air supply respirator for extensive use, and rubber gloves are a great start on the protection. Ear muffs if the hood doesn't muffle the noise.

The larger blaster has the dead man nozzle I hate. When you release it, it immediately causes your sand hose to fill with sand and plugs the blaster. The safety * have mandated this nozzle on larger units, for no apparent reason than they think sandblaster users have the IQ of a small rodent...If you feel you are smart enough to not let go of the nozzle and let it point at nearby humans, replace it with a normal nozzle or disable it with apiece of wire. Other than the nozzle and capacity it is the same blaster as the 40 pounder.

Media, I prefer slag products like Black Beauty for their aggressiveness. For sheet metal, fine sand is safer for the metal, but you MUST not breathe the dust.  My bud I was talking about has used plain number one white sand for years, blasting outside and using proper protection, with excellent results. (he does enough blasting in his restoration biz that he had to have a guy with a bucket loader scoop up all the waste sand and haul it away a few years back.. 20 years of blasting had made a big enough pile that it was in the way of the snow plow. )

[jeffb]

Phil thanks for jumping in.  I learned a lot and thanks Bill for all the information.  jeffb in sd

[macrisel]

I use an old Clarke pressure blaster and have had good luck with it.  When I started my willy resto, I searched the internet and found a picture of a 55 gallon drum that had been coverted into a sand blast booth.  I had a few extra drums laying around so I decided to copy the idea and make one of my own.  I cut out one end of the barrel and replaced it with a plywood door I made.

I also cut a viewing window in the side along with two round holes for gloves to fit through.  I made a wood frame to hold a piece of plexiglass for the viewing window.  To keep the plexiglass from becoming pitted up, I use a piece of Saran wrap to line the inside of the plexiglass.  After two or three sessions, I pop the glass out and replace the Saran wrap.

For gloves, I used a set of rubber lineman's gloves I had, but when these wear out, I'll get a pair of canvas sandblasting gloves.

For exhaust, I glued a plastic fitting into one end and use a shop vac to vent it.  A setup like this allows you to contain all the mess and dust inside the drum.  Also, when I'm finished blasting, I simply scoop up the media inside the drum, filter it out using a screen and reuse it.  I built this booth 4 years ago and have used it A LOT on my jeep.  So far, so good!

Here is a link to a similiar one (minus the exhaust stacks): http://www.youtube.com/watch?v=3RuuhjjGKOk&feature=related

For media

[macrisel]

For media, I like to use walnut shells.  They create less dust, seem to last longer when I re-use them, and don't get embedded in metal like sand will sometimes.

One final tip, take the time to clean the crud (grease, oil, dirt, etc) off the majority of the part you are blasting.  While the blaster can take it off, it will go MUCH faster (and be less strain on your air compressor) if you take the heavy stuff off before.

Good luck!