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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Sand Blasting ( SA 2,5) vs Water Jetting (700 - 1500 bar) Production Rates
Q. I work for a contracting company in Greece.
The company has been awarded a project regarding the cleaning and repainting of 10 steel fuel storage tanks (Diesel & Heavy Fuel Oil).
Before repainting the tanks, we need to remove the previous paint system. We have the option to do this either by using sandblasting to SA 2.5 or water jetting at pressures 700 to 1500 bar.
What is the best method in terms of production rates ?
- Athens, Attiki, Greece
2006
Q. We are a bridge and steel tank, sand blasting and painting company in the united states.
To answer your question, Water jetting does not give you any type of a profile on the steel, in which does not provide the coating anything to grab on too. If sand blasting is not used to remove the old coatings and water jetting takes its place the coating that is applied will within a few years fall off or you will be able to pool pieces with your hand. This procedure has been tried in the states and it has failed. Looking forward to discussing this further.
- Buffalo, New York, U.S.A.
2007
A. Hi Konstantinos and Aristidis
Aristidis, you are of course right when you are talking about steel surfaces without any roughness. But as the tanks are coated right now, there should be a profile (roughness) on the steel surface already.
That's why I think water jetting is much better in your case Konstantinos. When you remove the coating by water jetting the surface is ready for coating after it has been dried. Make sure, that you apply the coating as soon as possible in order not to have any loose flash rust on the steel surface (light flash rust is okay). In doubt, wipe over the surface and see if the rust is loose.
Water jetting has the advantage that you remove dirt, grease/oil, salts and the coating in one-step.
When you blast the surface you first have to clean the old coating with an emulsion especially to remove grease/oil (can be left out if there is no grease/oil on the surface), then you have to clean the surface with freshwater, then sandblasting, then remove the dust from the surface and first now the surface is ready to be coated.
In short: water jetting 1 work-step vs. sandblasting 3 or 4 work steps
- Copenhagen, Denmark
December 10, 2014
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