Sandblasting media

Jordan Baker · #1 08-07-09, 02:41

Hi everyone

I just picked up one of the big sandblasting cabinets from Princess Auto today as they were on sale. Anyway I not sure what kind of blasting media I should get.

I was told to stay away from the sand kind as it will wear out quicker since the cabinet contiuously resues the stuff.

Any suggestions??

Jordan

rob love · #2 08-07-09, 02:58

Personally I just use the sand I dig out of my back yard. I make sure it is dry, and sift it through some window screen. I prefill a couple garbage cans so I can make it through winter. The stuff works like a charm, costs nothing, and when it gets too fine it just gets sucked out of the vent.

For venting your cabinet, I would reccomend the princess auto dust collector. Toss out the filter bag mind you, and just shoot whatever it collects outside. They run about $120 and will keep the inside of your cabinet in a negative pressure state. This also prevents the dusts from sandblasting from escaping through the cracks in the cabinet. Duct tape also works well towards this....but put the tape on the outside of the cabinet. Inside will not be around too long.

I find that the gun will clog with various debris from the sandblasting. Things like chunks of rust etc. I plan to put another screen lower in the hopper to prevent the debris from getting to the pickup tube. While you can put your hand over the nozzle for a second and clear the debris, it just keeps coming back.

Also, be prepared to replace those gloves pretty quick. They tend to tear open fairly early in their life. The replacement gloves at princess are just fine.

Lastly, you may find small jolts of static jumping from your chest to the machine. It hurts like a bugger after a while. We get it here in the winter when it is especially dry, but it occurs on any dry day. For that I run a small wire to a sports wristband. The wire is attached to a snap which touches my arm. The other end of the cord is attached to the cabinet. Kind of evens out the electrostatic states.

Jordan Baker · #3 08-07-09, 05:46

Thanks for the info. I didn't know it needs an extra vent. Is it a must?

I will set it up tomorrow and try to give it a wirl on the weekend. I can't wait to try it out as I have never used a sandblaster before.

cantankrs · #4 08-07-09, 08:21

Quote:

Originally Posted by Jordan Baker

Thanks for the info. I didn't know it needs an extra vent. Is it a must?

Hi Jordan,

You've figured the air you're pumping in has to go somewhere. If you don't vent the cabinet by a powered means, after a very short while you can't see jack in there because only a fraction of the dust leaves with the exhaust air. Try it - if it's a problem go from there. Buying or building something to create some suction is probably necessary.

If you live in a high density housing area I'd reconsider ejecting silica dust into the air outside. If plenty of room then not such a problem. Just be sure it can't circulate back into your home or shed. I'm considering building a water sprayer unit to direct the exhaust thru so the particulates drop out of the airstream to form sediment. Depends entirely on your surroundings.

Some people use silica sand and bugger the consequences, others pay good money for Garnet which I've been told is not toxic. You can buy glass beads from a blasting media distributor, and even crushed wallnut shells, possibly plastic blasting beads, etc, etc.

Glass beads probably good idea for aluminium items.

Have FUN!

Alex

Alex Blair (RIP) · #5 08-07-09, 13:43

Quote:

Originally Posted by Jordan Baker

Hi everyone

I just picked up one of the big sandblasting cabinets from Princess Auto today as they were on sale. Anyway I not sure what kind of blasting media I should get.

I was told to stay away from the sand kind as it will wear out quicker since the cabinet contiuously resues the stuff.

Any suggestions??

Jordan

Jordan
Before any sand blasting ,cut some clear light Plexiglas windows over the inside of your permanent viewing window..Duct tape tightly around the edges so dust won't get between the two glasses..(At least some heavy clear flexible plastic sheeting)
Then you are ready to sand blast..You do this to protect the permanent window clarity..
When sand blasting you will inevitably point the blasting nozzle at the window..when you are all liquored up or asleep..That will instantly give you a nicely "Frosted" window that you can't see dick through..
And the ordering and installing of an expensive window..
Do it before you start and save your self a lot of annoyance down the line..
Guaranteed you will replace it twice a year if you are careful..

Jordan Baker · #6 08-07-09, 14:43

Thanks again for the help. I'll look into the venting aspect today.

The mediums that they had were
crushed glass (#50) 20-35
aluminum oxide (80 grit) out of stock
crushed walnut shells
and some kind of slag, cant remember the name

Adame · #7 08-07-09, 16:42

Hi Jordan

I bought a soda blaster. In Milton. It uses baking soda and is enviormentally friendly. (rain washes it away).

It removes paint grease etc. But doesn't damage metal etc.

Cheers
Adam

REL · #8 08-07-09, 18:20

Wear a good HEPA mask when you're using it. I speak from experience. Silicosis is not fun. Glass beads...last I heard glass is silica and silica is glass, as they are used the beads break down into shards which work even better than beads due to their sharp, irregular shapes, until they break down to the point where they are too small and light to work. Glass dust is glass dust. You don't want to breathe it.

Even if you use steel shot or some other media that does not break down, there are all kinds of interesting bacteria, fungi etc. living on old rusty objects. You don't want to inhale them. Your lungs are a nice warm, wet dark place, where such things like to grow if they can. Of course some people can tolerate more than others.

Those old paints were mighty toxic sometimes too.

Fresh air supply to your mask with a remote hose is best if you can be sure of an inlet location for your hose that won't be contaminated by blown dust etc. from the dust/media collector's outlet. That's what the professionals use.

Soda is excellent for soft metals like brass and aluminum or thin steel which peens and warps with sand, and sometimes even with glass beads. Too bad the media is so expensive.

Poor man's sandblaster is a siphon feed for a pressure washer. Keeps the dust down, but best done on a very hot day.

George McKenzie · #9 08-07-09, 19:36

I made a blasting cabinet for $300 . Check it out in Army Motors #125 . This is the best one I have ever seen . It is made out of an old truck sleeper . I put a hopper under it and it is on small wheels can be moved easily out of your way or shared with another person . I use my shop vac with a long hose so it is outside ,because of the noise. There is a fine screen that catches most of the dirt and paint that I vacume up ,and when it is too bad I can open the bottom and reclean the blasting material . I use glass beads (4) bags . This will do things 7 ft long .You can get plastic window cover to cover your window to stop it from getting blasted up from Princes Auto .We have done wheels ,heads, fenders ,doors .ect. The old truck sleepers can be bought for $20 and the only thing you have to do is make two holes for the hand gloves .put a plastic window over the hole that the driver used to get into it , a screen on the bottom and some lights .I might add that if you sodablast be sure you clean off the soda as it will cause rusting when it gets wet and forms an asid .If any one needs more info EM me

rob love · #10 08-07-09, 20:45

With regard to the window getting sandblasted, I have gone to a different solution. I just let it get blasted. The plastic frostshields to protect it run about $3 each, and get sand etched rather quickly. Instead, I just replace the glass every few months. Princess used to have them for just $8 each. I had a small stack of them, although I also notice that princess seems to have quit stocking the replacement glass.

WRT the air exhaust, there are actually two ports on the cabinet. The one on the left would be for fresh air intake, while the one at the back of the cabinet will be for exhaust. I used to use a modified fan for the exhausting, but the dust was destroying the fan annually. Without the negative air pressure, you will not see anything.

WRT all the various environmentally friendly and health conscious blast media, the problem with any of it is that the end result of blasting adds things like the lead based paint, rust, possible asbestos, and whatever else is present on the item being sandblasted. So in the end, anything used must be considered toxic. Maybe just less toxic. With a good vent fan on your cabinet, you will have no need for masks or supplied breathing air. The cabinet will be in a state of negative pressure, so nothing will escape it.

cletrac (RIP) · #11 08-07-09, 21:04

When it comes to protecting a vision port the best thing I've found is a piece os Saran Wrap or the like. The sand bounces off without making a mark.
I agree with Rob on the media bit. Sand is cheap and you don't want to breathe the dust off any of it. This thread http://www.class-five.com/~mlu/forum...t=sandblasting
shows the cabinet I made.

Snowy · #12 29-07-09, 04:42

Quote:

Originally Posted by rob love

WRT the air exhaust, there are actually two ports on the cabinet. The one on the left would be for fresh air intake, while the one at the back of the cabinet will be for exhaust. I used to use a modified fan for the exhausting, but the dust was destroying the fan annually. Without the negative air pressure, you will not see anything.

I'm working on improving my el-cheapo sandblasting cabinet at the moment and am thinking that an extraction fan could benefit from a cyclonic seperator as well as a fine particle filter. Some vacuum cleaners use this method and they seem simple enough to make after seeing this article on Hack-a-Day a few days ago: http://hackaday.com/2009/07/19/cyclo...st-seperation/
Principle of operation: http://en.wikipedia.org/wiki/Cyclonic_separation

Steve.