Dose anyone know where I may be able to buy a small home use soda blasting machine?

Try this link out

http://www.eastwoodco.com/jump.jsp?itemID=1408&itemType=CONTENT&path=32&KickerID=395&KICKER

How is this with cleaning the underside with decades of grease / dirt, etc.?

If its dry grease or stain prolly would work, but if its wet or rubbery, will prolly bounce off

Do not use soda blast under painted areas, there has been much discussion about this one on many different autobody forums and the consensus is that the primers will not adhere to the soda blasted (soda is sodium which is salt) UNLESS you wash multiple times with Purple Power AND a pressure washer. Kinda defeats the purpose of bare metal. Many here will probably disagree with me, but it more or less is proven, many people have had complete paint failure by using this process, why take the chance?? Use Sand, Starblast or glass beads to blast body parts or small parts. C

For small parts, its just much better/easier to use glass bead. Soda media is expensive. Cant be re-used and takes high psi to be effective.

Soda blasting leaves a nice, smooth finish to the metal, but it leaves you with an immediate disadvantage when it comes to prep compared to other available medias.

Where is the best deal on glass bead material? I've read about several grades / type of beads.... what would work best on an undercarriage?

Where is the best deal on glass bead material? I've read about several grades / type of beads.... what would work best on an undercarriage?

I'm all ears on this one!