steps to a more effective power tool cleaning presented by: earl bowry, jotun paints, inc
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Steps to a More Effective Power Tool Cleaning
Presented by: Earl Bowry, Jotun Paints, Inc
Introduction• This webinar will explain power tool cleaning and
how to effectively remove loose rust, loose mill scale, and loose paint.– The presentation will describe two types of power tools,
electrical and pneumatic– It will describe how the use of high efficiency
particulate air (HEPA) will reduce air pollution– It will describe how power tools are used for spot
cleaning of damaged coatings, when contamination of adjacent areas by abrasive is unacceptable and when a surface-tolerant coating such as oil-based paint is to be used
Power Tool Cleaning• Is a method of preparing steel
surfaces by the use of power assisted hand held tools
Power Tool Cleaning• Cleans by impact, abrasion or both• Used frequently for spot cleaning of
damaged coatings• Is commonly used to clean difficult
to reach areas or missed areas after abrasive blasting
• Is used when other forms of surface preparation are not possible or cost effective
Power Tool Cleaning• Two Basic Types:
– Electric– Air Driven
Power Tool Cleaning• Pros:
– Can be done in confined areas or where abrasive blasting will damage sensitive equipment
• Cons: – Slow and physically tiring for the
operator– Power tool cleaning media wears out
and has to be replaced during the work
Power Tool Safety• Eye and face protection is required
to prevent injury caused by flying particles
• Ear protection is required because of the loud, constant noise
• Wear gloves, boots and hard hats if the particular job requires it
Power Tool Safety• Never run electrical tools in wet
areas• Use ground fault interrupters• Use respirators to filter dust and
debris • Power tools can create sparks, so
take care when using near volatile vapors and combustibles
Contractor Safety Responsibilities• Provide proper safety equipment for
the job being performed• Train workers to use the safety
equipment
Worker Safety Responsibilities• Be familiar with the safety
equipment provided• Make sure safety equipment is in
good working condition• You are responsible for your
actions!!
Owner Safety Responsibilities• Assure that proper safety practices
are followed
Types of Power Tools• 3 different types of power tools used
for surface preparation:– Impact cleaning tools– Rotary cleaning tools– Rotary impact cleaning tools
Common Electrical and Pneumatic Equipment• Sanders• Wire brushes,
wheels & grinders• Chipping
hammers• Scalers• Rotary/Impact
tools• Needle guns
Sanders
Important note:Grit size and distribution (open/closed) are important factors
Wire Brushes, Wheels & Grinders
Important Note:Wire type and hardness are important factors
Chisel Scaler
Important Note:Generally used for large scale particle removal
Flapper Wheels
Use:Can quickly remove heavy layers of rust and paint.
Rotary/Impact Cleaning
Needle GunsImportant Note:Needles can get dull fast and may need to be replaced several times in a work shift
Reduction of Air Pollution• High efficiency particulate air (HEPA)
vacuum lines attached to reduce air pollution and collect debris produced in cleaning operation
HEPA• High-efficiency particulate air • HEPA is a type of air filter• To qualify as HEPA by US
government standards, an air filter must remove (from the air that passes through) 99.97% of particles that have a size of 0.3 micrometers or larger
Specifications• The specifications governing power
tool cleaning are:– SSPC-SP 3, Power Tool Cleaning– SSPC-SP 11, Power Tool Cleaning to
Bare Metal– SSPC-SP 15, Commercial Grade Power
Tool Cleaning– ISO 8504-3, Hand and Power Tool
Cleaning
SSPC-SP 1, Solvent Cleaning• SSPC-SP 3, SSPC-SP 11 and SSPC-SP
15 require removal of all oil, grease, dirt, etc. in accordance with SSPC-SP 1, Solvent Cleaning, before cleaning with power tools
SSPC-SP 3, Power Tool Cleaning• Removal of loose rust, loose mill
scale, and loose paint to degree specified
• Intact materials may remain such as:– Mill scale– Rust – Paint
• Materials considered intact if they cannot be removed by lifting with a dull putty knife
SSPC-SP 3, Power Tool Cleaning• Specified when rigorous surface
preparation is not required, such as a dry interior
SSPC-SP 11, Power Tool Cleaning to Bare Metal• Remove tightly adherent materials to
produce a surface that is visibly free from all rust, mill scale and old coatings
• No staining permitted• Slight residue permitted in bottom of pits if
the original surface was pitted• Requires a 1 mil minimum surface profile
SSPC-SP 11, Power Tool Cleaning to Bare Metal• Examples of circumstances where
this specification may be applied are:– Touch-up of welded or damaged areas
of erection assemblies– Reducing volume of hazardous waste
produced by abrasive blasting– Cleaning around sensitive equipment or
machinery
SSPC-SP 15, Commercial Grade Power Tool Cleaning• Requires the removal of all paint,
rust, mill scale and other foreign matter
• Allows random staining on 33% of each unit area (9 in2)
• Slight residue permitted in bottom of pits if the original surface was pitted
• Requires a 1 mil minimum surface profile
ISO 8501• Combines hand and power tool
cleaning in one standard• Has two grades of Cleaning:
– St 2 – Remove all oil, dirt and poorly adhering mill scale, rust, paint and foreign matter
– St 3 – Same as St 2 but more thoroughly cleaned until a metallic sheen is observed
Surface Profile• ASTM D4417, Method B (Unless
Otherwise Specified)– Digital Surface Profile depth micrometer
Profilometer
Surface Profile: SSPC-PA 17
• Procedure for Determining Conformance to Steel Profile/Surface Roughness/Peak Count Requirements – Describes a procedure suitable for shop
or field use for determining compliance with specified profile ranges on a steel substrate
SSPC-VIS 3• Guide and
Reference Photographs for Steel Surfaces Prepared by Power- and Hand-Tool Cleaning
SSPC-VIS 3• This guide describes the use of
reference photographs depicting the appearance of unpainted, painted, rusted, and welded hot-rolled carbon steel prior to and after power and hand tool cleaning
• These photographs are intended to be used to supplement the written SSPC power and hand tool surface preparation standards
SSPC-VIS 3 Initial Conditions
• Condition A: Steel surface completely covered with adherent mill scale; little or no rust visible
• Condition B: Steel surface covered with mill scale and rust
• Condition C: Steel surface completely covered with rust; little or no pitting visible
SSPC-VIS 3 Initial Conditions
• Condition D: Steel surface completely covered with rust; pitting visible
• Condition E: Previously painted steel surface; light colored paint applied over blast cleaned surface, paint mostly intact
• Condition F: Previously painted steel surface; zinc-rich paint applied over blast cleaned steel, paint mostly intact
SSPC-VIS 3 Initial Conditions• Condition G:
Painting system applied over mill scale bearing steel; system thoroughly weathered, thoroughly blistered, or thoroughly stained
SSPC-VIS 3 Steps• Determine initial condition of steel
– Select the photograph of the condition that most closely represents the appearance of the steel to be cleaned
• Determine the power tool cleaning level to be achieved (SP 3, 11 or 15)
• Select the tool to achieve the specified level of cleanliness
• Use the photos in VIS 3 that represent the end condition based on the proper tool and specified level of cleanliness (i.e., SP 3/PWB)
Summary• Use of portable power tools-
pneumatic and electric- is common for cleaning operations. Through careful selection and use of the great variety of power tools and accessories, many cleaning operations can be accomplished rapidly and produce satisfactory surface conditions with reasonable labor costs and good paint life
• Questions?????
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