Re: abrasive blasters


Richard Hendrickson
 

On Jul 14, 2005, at 10:12 PM, Mike Barone wrote:

I've had considerable experience with these in recent years. Even though I use a Badger unit, the air supply from an ordinary hobby size compressor is insufficient. It is necessary to obtain a unit capable of about 4 cfm at 40 psi. (Most hobby compressors are about 1/2 cfm at 25 psi.) A decent compressor can be bought at most hardware or tool supply store. Get one with a pressure regulator and at least a 2 gal. tank. You may wish to add to it a about 10' to 15' of copper piping, coiled, to form a cooler and a moisture trap such as those that can be found in the Walthers catalogue. This last is essential since any moisture will cause clogging.
You're right that a compressor intended to drive an airbrush won't generate enough pressure/volume. I use a home shop compressor purchased at a big box hardware & building materials store which has enough power to pump up auto tires, supply a big paint spray gun, etc. I haven't found a pressure regulator to be necessary; I just adjust the relief valve on my compressor to get the desired air pressure. Nor do I need a moisture trap; however, I live in a dry climate. If you live in a place that gets a lot of 90+% humidity like Buffalo or Houston, a moisture trap might be desirable or even essential.

Also get a shop vac to evacuate the air and keep the booth under negative pressure. A cheap Sear one will do. If your booth doesn't have a connection for this, you can make one and bolt it over an existing vent on the booth. Note that this vent must also have a filter to prevent all the grit from being sucked out into the shop vac. And for further protection, use one of those dust filters available at hardware stores.
I haven't found any of this to be necessary, either, though breathing through a dust filter is obviously a good precaution. I have a clear plexiglass front on my sandblasting booth in which there are two arm holes with elastic cuffs cut from a cheap nylon jacket, so the abrasive powder can't escape from the booth. Seems a simpler way to confine the abrasive to the booth than what Mike is suggesting, but YMMV.

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