Replacing blast media

[Lewis_McDorman]

I have a benchtop blast cabinet that has sand in it. Lately, the sand doesn't seem to be cutting as quickly as it used to. Does it become to powdery to work effectively if it's reused too many times? All other components of the system are working to design specs.

Thanks.

 

[anthony7777]

lewis-m, the life of the media depends on what your blasting, using it on clean metal would/should give a longer life then when blasting something that has many layers of paint, oil, or a baked on surface.

 

[JamesWilson]

It depends on the "grit" too- some stuff is coarse and can be reused more, becoming "fine" grit after a while. Higher pressure can compensate somewhat, but that can be hard on thin materials.

 

[Cottontop]

anthony,

You have it backwards.

Directing a hard blast media onto an even harder surface (bare steel) will "wear off" the sharp cutting edges of the media fairly quickly. In the range of blasting media, silica sand is fairly soft. Most steels are fairly hard.

Directing a hard blast media onto fairly soft surface will make the blast media last much longer as the soft material will not cause the blast media to destroy itself as easily.

As a test, bang a rock on a railroad track, then on a wooden 2x4. See what happens to the rock. Just like using sand as a blast media, on bare steel, you'll eventually pound the rock to dust.

In the range of blasting media, silica sand is cheep, but it is pretty soft. A harder blasting media (such as Aluminum Oxide) will cost more, BUT will last much longer

I have long used aluminum oxide as a blast media. It will cost 2-3X as silica sand, but should last 3-5X longer.

Lewis, Look up "blasting" in your local yellow pages and you should be able to find a wide range of blasting media that you can buy in bulk. The more you buy, the cheeper it'll be.

Just keep it dry when storing.

Tim

 

[Grantura_MKI]

Yup! Try out blasting your alli bits with glass beads. I keep buckets full of different type of media...glass, silica sand and walnut shells.

 

[jgrewe]

Second the aluminum oxide. I have a 6' blast cabinet with a huge dust collector that I ran sand in for years. I got tired of all the dust and broke down and bought some AO. It cuts faster and only needs about 40-50 psi to work. Expensive but worth every dime when you see how much time it saves.

 

[Grantura_MKI]

AS I said, have a bucket full of different media, depending on the job or result that you want.

 

[hottvr]

Depending on the job, I'll swap out glass beads with sand. At 4 bucks a bag for sand and $1 a pound for glass beads the sand wins out and I save the glass for more delicate stuff.

 

[Hap Waldrop]

The type media depends on what you are blasting, if it's rough , rusty parts, then sand or aluminum oxide works well, if more delicate work is needed for like engine parts, which is what I'm mostly blasting, then glass bead, I use a fine glass bead in my big Skatblast cabinet, then in a second blast cabinet I use plastic media for carb parts.

I think one othe worst mistakes you can make with a blast cabinet is thinking is some sort of magic wand, some serious clean up needs to take place before the part ever makes it way into the cabinet, heavy rust scale, thick coats of paint all need to be removed from a part before it is blasted, otherwise you will just clog up your cabinet. Another consumable on your bead blaster is the tips, most cabinets come with white ceramic tips, which wear extremely quick, and if your tip has worn until it has huge ID in it now, compared to when it was new, then the overall pressure and effectivness of the blaster is compromised. Now I used my bead cabinets alot, everyday, so I go thru a few hundred pounds of glass bead every year, and when I used ceramic tips, I went thru them like crazy, I looked at what TP Tools had to offer in tips and they offered a carbide tip, it was expensive when compared to the replacment packs of ceramic tips, alot higher, like $40 buck for the single carbide tip, but it was the best decision I ever made, blaster-wise, because I'm into my third year with the same tip, in the same amount of time, I would have went thru several dozens of ceramic tips , so in the long run the carbide tip was cheaper to use.

 

[Banjo]

WARNING!!!! Use a respirator if you are using sand as a media!!!! The silica is VERY nasty for your lungs!!! Even in a cabinet!

 

[Greg_C]

I use silica sand in my cabnit and do need to replace it
from time to time.
I plan on getting a smaller unit for use with AO.
I also run glass sheets thru the big unit for decorative ( non-auto)
work.
I don't use a pickup tube system anymore, just run the gun from my TIP pressure tank thru cutouts, and rescreen the sand until it's too fine.
The cabnit has a vac system to clear the dust.
Silica is dusty, and as Banjo says, NOT something you want to breath in.