Sand blasting equipment and media

[oklahoma red]

Much has been discussed about sand blasting. A lot of guys starting out have been asking about cabinets and compressors. I'll toss my nickel into the pot.
Everyone is pretty much correct in that a good size compressor is definitely needed. Along with that are some other things to consider. If one is sandblasting big metal structures or stripping car frames then a HUGE compressor is needed because your pumping a monster amount of air thru a big nozzle and some poor dummy is shoveling media into a hopper as fast as he can go. Without doing a bunch of digging in the archives I will say I've not seen anything recent on nozzles. One should try to size the nozzle (the diameter of the hole going thru it) to what you are trying to accomplish. Precision blasting will be best done with a small orifice. That in return somewhat reduces the size of compressor needed but at the same time requires more time to accomplish the end result. The companies that make the blast cabinets will recommend what size compressor is required with any given nozzle size.
Next is what type of media are you going to try to use. "Sand blasting" is generic to a large degree. The most common media is of course "sand". Unless it has been washed and screened for size you're liable to get just about anything going thru the hose. Then there is aluminum oxide and silicone carbide. These are extremely fast cutting and it wouldn't take but a blink of an eye to blow a hole right thru a piece of briar. Of no real value to the pipe maker is crushed walnut and pecan shells and carbon dioxide or wet slurry blasting. My personal preference is glass beads. These come in many uniform mesh sizes and are slow cutting unless you have a spongy piece of briar. I'm far from an expert pipe maker but I have been around media blasting a lot. I'm fortunate to have a nice blast cabinet of about 6 cubic ft and a Kaeser screw compressor. Total of about ten grand but I use it everyday for my "real job".
There are a lot of other variables in media blasting such as the pressure being used, suction feed or pressure feed on the media, the distance of the nozzle to the part, how fast are you moving the nozzle over the part, etc.
I for one would be very interested in hearing what the pro pipe makers are using for their media and tips on nozzle sizes and air pressure settings. Of course some of that info may very well be trade secrets.

[taharris]

This is good information. Thanks for posting.

Todd

[baweaverpipes]

Next is what type of media are you going to try to use. "Sand blasting" is generic to a large degree. The most common media is of course "sand".

Do NOT use "sand", unless you want silicosis.
"WARNING!
Abrasive blasting with sands containing crystalline silica can cause serious or fatal respiratory disease."

[oklahoma red]

No matter what the media is, one should always wear a respirator. Even with a sealed cabinet with rubber gauntlets clamped around the arm holes there is always some of the dust in the air, particularly when you open and close the door/lid to put objects in or take them out and when blowing off residual media.
BE SAFE!

[KurtHuhn]

Then there is aluminum oxide and silicone carbide. These are extremely fast cutting and it wouldn't take but a blink of an eye to blow a hole right thru a piece of briar.

This is, actually, false. Both can be used to great effect by the pipe maker. You need to know when and where to use them, as well as what jet and orifice to use, and what pressure they work best at - but they are useful.

[oklahoma red]

Then I stand corrected. Obviously one should gain experience before using either of those materials. Watching a chunk of your pipe disappear is akin to dropping it and snapping off the stem or breaking it while stamping. It would make you wanna bawl. It is definitely a balancing act to get all variables to come together to make the perfect blast.
I notice no one has chipped in any specifics. I suspect my comment about trade secrets is true.

[Sasquatch]

It's true but also mostly irrelevant. Bruce could tell me his exact setup and I'd be able to go and get totally mediocre results with it.

Basically, small grit and high pressure will yield you better detail. Sharp, hard material cuts faster than dull/soft material.

[RadDavis]

It's true but also mostly irrelevant. Bruce could tell me his exact setup and I'd be able to go and get totally mediocre results with it.

Basically, small grit and high pressure will yield you better detail. Sharp, hard material cuts faster than dull/soft material.

And aluminum oxide will eat a pipe if you're not very, very careful.

Rad