Sand Blasting a Gas Tank - What Media?

[Steve Braverman]

I am trying to clean out a gas tank that has been sitting with nasty gas in it for many years. The local radiator shop cut open the ends for me, and the inside is coated with heavy rust and scale. I want to sand blast the inside of the tank, but I'm not sure how to go about it. I got a shiny new sandblaster for X-mas last year, and it's still in the box. Should I use regular sand, baking soda, or something else? Where can I get blast media locally?

[Guest palosfv3]

The money move would be to boil out the old gas / sludge and then fill the tank with a vinegar solution. This will remove all rust inside the tank over a couple of days time. The problem with this approach is that you must immediately seal the clean metal . It will rerust in a very short time. Sandblasting will not do as good of a job unless the tank is split open . I have used a retining service on a couple of tanks over the years . They basically will remove all rust and scale chemically ( careful with any brass fittings ) and regalvanize the entire tank . There was a small hole that had to be resoldered but that was a minor issue to contend with.

[Bhigdog]

If you're committed to abrasive cleaning I would go with a fine grade of commercial blast media. Regular sand isn't uniform in size, may be dull, and has a high silica content. Bad for whoever is exposed to the dust. Around here silica sand media is hard to find anymore. Pretty much everyone uses a black crushed slag media. It's very low or no silica and cuts very well. The brand name around here is Black Beauty and goes for about $15 for a 100 pound bag. You should be able to find "sand blasting" in the yellow pages for some leads. Some of the auto parts stores that cater to the trade carry it around here.

If you do blast, the finish it leaves gives an excellant "tooth" for holding a coating and you will have to coat the tank when you're done.

Don't be surprised if the blasting opens up lots of pinholes that should be soldered closed before coating..........Bob

[mrpushbutton]

Anymore I just take tanks to the local radiator shop and have them perform the "Re-nu" process, if the exterior of the tank is visable and you don't want the slathered-on black stuff on the outside, tell them not to coat the outside. The process gets the tank clean and coats it against re-rusting with a goo that doesn't care about the changes in gas formulation.