There have been a couple of designs posted here. Unfortunately the
bookmarks that I have for them are no longer valid:
http://www.geocities.com/picketfence...cts/sand1.html
http://www.tcis.net/~kwag98/Sblaster.htm

I don't know who the owner of the 1st was/is, the 2nd one was "Wild
Bill". How about it, 'Bill, do you have a new link to yours?

If you Google-group RCM for "pressure blaster", you'll find a few threads.

Bob
(from now on I'm going to save the web page, not just the link)