Surface Preparation - HKIMT Sponge Jet (HKIE).pdf · Surface Preparation and Coating Division EXA GROUP LTD ©2008 Sponge-Jet Inc. ... Wet Abrasive Blasting Dry Ice Blasting Bristle

Surface PreparationWarners Suen

Surface Preparation and Coating DivisionEXA GROUP LTD

©2008 Sponge-Jet Inc. All rights reserved.

Surface Preparation is important?


Tools For Cleaning

•Hands Tools-Wire brushes, Scrapers, Chisels, etc.

•Power Tools-Rotary wire brushes, Needle Scaler, Grinder, MBX, etc.

•Dry Grit blasting-Mineral, e.g. SiO2, Al2O3, Fe2O-Soda powder, Corn powder, Dry Ice (CO2), etc.

•Water jetting-LPWC, HPWC, HPWJ, UHPWJ-Slurry blast- Inhibitor


Visible contaminant- Heavy Rust- Mill Scale- Heavy Deposits (Salts and Mineral

Sludge)- Oil / Grease / Waxes (Petroleum

Based)- Old Coatings

Invisible contaminant- Soluble Salts (Chlorides, Sulphates- Acid / Alkali- Fatty Acids, Petroleum- Silicone

Contaminant Removal


Standard of Surface CleanlinessAbrasive Blasting

Standard RandomStaining

Cleanliness

NACE No.1 / SSPC-SP 5 / Sa 3White Metal Blast Cleaning

None Free of all visible oil, grease,dust, dirt, mill scale, rust,coating, oxides, corrosionproducts, and other foreignmatter

NACE No.2 / SSPC-SP 10 / Sa 2.5Near-White Metal Blast Cleaning

5%

NACE No.3 / SSPC-SP 6 / Sa 2Commercial Blast Cleaning

33%

NACE No.4 / SSPC-SP 7 / Sa 1Brush off Blast Cleaning

Traces of tightly adherent mill scale, rust,and coating residues are permitted toremain on 10% of each unit area


Regulations

United Nations – IMO (International Marine Organization)SOLAS (Safety of Life at Sea)SOLAS Regulation 3-2 based on IMO Recommendation A

798 of July 1, 1998 stares that ship’s ballast tanks shall beabrasive blasted to ISO 8501 Sa 2 ½ (Near White Metal).


Background

Weld seams are rarely prepared properly prior to coating.

Even if prepared properly, are normally the first location of corrosion due tosurface irregularities, stress corrosion, increased hardness and the low levelgalvanic reaction of the weld to the adjacent steel.

US NAVY – Guidelines indicate thatthe best coatings applied over powertool preparation will last a maximumof 3 years vs 20-30 years forabrasive blasted surfaces.


Life Cycle Costs

Shipyards rarely have a vested interest in coating performance greaterthan 5 years – in fact generally their liability ends at 1 year or less.

In a cost model on the economics of coatings in shipsballast tanks 25 year life cycle cost were reported forvarious quality of coatings systems*.

• A common system (with 5 year expected life) wouldultimately cost $113 per square meter.• A high performance system (with a 30 yearexpected life) would ultimately cost $46 per squaremeter.

*Ref: Economics of Coatings/Corrosion Protection of Ships. Johnny Eliasson, Stolt-Nielsen Transportation Group B.V.


Normal Cleaning Practices

The reason prefer hand tools to abrasiveblasting is:

• Does not damage adjacent coating withblast media rebound.

• Can be done in close proximity to othertrades such as pipe fitters andelectricians.

• Minimal dust collection so ventilationducts are not required throughout theship.


Goals of Abrasive Blasting

Clean Rust Create Profile Dust Control Low Pressure

Bead Blasting

Wheel Blasting

Hydro Blasting

Wet AbrasiveBlasting

Dry Ice Blasting

Bristle Blasting

Bead Blasting

Wheel Blasting


Bristle Blasting


How manycan cleanthoroughly?

How manycan profileuniformly?

How manycan achievelower dust?

How many canachieve highersafety?


What is the result?


SPONGE JET OVERVIEW


Sponge Blasting Equipment


Technology of Sponge Media™

Sponge Character:-Soft-Low Rebound-Absorb Dust

Mineral Character:-Stiff-Clean adhesion underpressurized


Ordinary Blasting versus Sponge Media Blasting


Sponge Media™ Advantages:•Clean, dry blasting process•Low dust generation•Low Rebound•Wide range of profiles•Reusable•Non-Sparking

New Abrasive Blasting Technologies


Applications – Marine


Application – Oil and Gas


How do Sponge Jet Save your Money?

Eliminate Rework

No need rinse or re-blast

Less need for extensive scaffolding

Protect sensitive equipment

Reduce Air Management cost

Reduce Waste Disposal cost


Achievement of Sponge Blasting

Clean Rust Create Profile Dust Control Low Pressure

99.9%Dust free

Up to S.A. 3White metal

0-100 microns 3 Bars orLess


Blast Where You Want…When You Want

Call or WhatsApp me on 9203 6351

[email protected]


Additional Information – Emission Test

22


Additional Information – Hot Surface Ignition Study

23

Documents

Surface Preparation - HKIMT Sponge Jet (HKIE).pdf · Surface Preparation and Coating Division EXA GROUP LTD ©2008 Sponge-Jet Inc. ... Wet Abrasive Blasting Dry Ice Blasting Bristle