The Cost of "DIY" Media Blasting..., or Should I buy the equipment for only one car project... Options

[73Phoenix20]

I know some of you folks will have some advise for me on this subject...

I need answers to several questions regarding media blasting...

1. Is the 'Pressure Pot" Blast System significantly superior to the gravity fed system?
I can get either one at Harbor Freight (and prolly other places) for about $50.00 difference, which is trivial, IF the Pressure Pot system really works better...

2. I can get Aluminum Oxide media for $40 per 25lb box... how much surface area will this cover, assuming I am removing the factory paint down to bare sheetmetal? 5 square feet? 10 square feet? More? For an easy example, will 25 lbs strip the hood of a 914? Or maybe the hood and trunk (top surface only)?

3. I can get crushed walnut shells for about $20.00 per box, but i assume they are much less effective? How much less? Will it take twice as much in walnut shells vs. aluminum oxide?

4. Luckily, I only need to strip the exterior, as the interior is in fantastic shape, and I am repainting to original color. What is the best material to use to mask areas that I don't want to get "accidentally" blasted? Heavy duct tape? Multiple layers of heavy plastic sheeting?

5. Will Aluminum Oxide risk warping of the sheet metal due to heating? I understand walnut shells won't warp panels? True or not? If they are only marginally less effective, and half the price, I guess I will go with the walnut shells?

Prolly more, but that is all I can think of right now! Thanks folks!

[Brian Mifsud]

Baking soda is a "salt", so you should be very careful to rinse the car very thoroughly, otherwise it will exacerbate rusting. Ideally, you use very pure water to rinse the car, or even slightly acidic (add vinegar?) to neutralize the baking soda.

That's why I'd go with something chemically inert like Alumina or Walnut Shells.