Tank Prep for Paint - Sandblast or leave some paint?

[Groover]

If you are prepping a not-so-bad tank to be painted with just a few chips, and on it's on what will be 3rd paint job including factory color, would you sandblast it or sand down the paint/factory paint down enough to get a good paint job (so it leaves the factory anticorrosion layer in place).

If sandblasting, would you use something like this to keep if from rusting before the paint job?


http://www.eastwood.com/eastwood-afterblast.html?fee=7&fep=5192&adpos=1o1&creative=61491489540&device=c&matchtype=&network=g&SRCCODE=GA220010&gclid=CO-ivOrBgsQCFQyEaQodY68AMg

Is there an equivalent that can be purchased at a regular Wal-Mart type store?

Thanks for the assistance.

[jomarti3]

I suggest wet sanding down to original primer if it is intact.  Feather ( sand out uneven surface) areas of chipped paint so they are smooth.  Reprime any bare metal areas.

[RinkRat II]

Media blasting is better than sandblasting thin metal for less distortion. Check your yellow pages for a shop that does it. A good automotive primer  of two or three coats wet sanded down to 600 grit and your good to go. Already two coats on there is a little thick for a quality repaint . IMHO ~; Good Luck

    Paul :BEER:

[Chuck in Indiana]

Sand it..

[Dimples]

It's very important that you clean the surface of contaminates--wax, silicone, etc. (don't grind them in). There are products for this first step.

Then wet sand it (by hand). Sequence with 150, 180, 220 grit. Then spray primer. Wet sand again, this time sequence with 320, 400, 600 grit (if you go through the primer re-coat). Then spray color (lay decals) and clear coat.

There's additional technique required for decals under clear coats. For professional results (base coat/clear coat) you should really take it to a pro. You might actually save money in the long run. A catalyzed clear coat will resist fuel spills.

[Chuck in Indiana]

Dimples pretty much has it covered. There's a fair amount involved with paint prep. That's why getting a good paint job costs so much. If you really care, and you have to ask, take it to a pro. Not trying to be a smartass here...

[Triple Jim]

There are lots of ways to do it, and I'm not disagreeing with the above...   Around 1979 or so I sandblasted a set of motorcycle sheet metal parts down to bare steel, primed with DuPont Corlar 2-part epoxy primer, and followed with DuPont Imron, a 2-part polyurethane paint.  It looked professionally done at the time, and still looks darned good 36 years later.  The only sanding was to smooth up the Corlar before spraying the Imron.  Of course if there's any Bondo type filler, sandblasting is probably out unless you don't mind redoing the filler.

[canuck750]

I grew up in a body shop, dad was a body man all his life and way back then paint was always chemically stripped or sanded off, never sand blasted. Soda blasting is a good way to remove paint if you have the equipment but chemically stripping is a good second choice. Sand blasting can do a lot of damage to the metal surface.

I gave up painting my own stuff a couple years ago when I found an older body man who specializes in bikes, he uses aircraft paint stripper, phosphorous acid to get any rust out of pours then neutralize with soap and water followed by metal etch primer.

[krglorioso]

What Canuck said.  Aircraft stripper gets everything off, including your skin if you choose not to wear gloves and EYE PROTECTION!!!  In case there's any Bondo under the old paint, you'll know about it this way and it's a lot less work.

Ralph

[Groover]

Thanks guys. I'll be taking the parts to a pro and let them handle-it. My questions was mainly out of curiosity and just to see what the general consensus was on this, and also because I was tinkering with the idea of doing the prep myself. From the replies, I'd say that in my case I think just sanding may be the preferred method since they aren't in too bad of shape.

Thanks again for the replies.

[Asylum]

Usually sand blasting is used to remove rust. Apart from that I only sand and feather edge, spraying etching primer on the bare metal areas and then filler primer on the whole piece. Filler primer will hide sand scratches more than if you only used etching primer.