Abrasive Blasting "Sandblasting"

Neumann Contractors have the capability to Abrasive Blast using either Steel Grit or Crushed Glass media at our Currumbin facility on the Gold Coast.  Steel Grit is for use on any heavy Industrial plant and equipment, marine vessel & structure, truck bodies or trailers and can be completed up to Australian Standard class Sa3 (White Metal) or as required.  Crushed Glass can be used on lighter steels, galvanized steel, stainless steel or aluminium. 

Call Peter today for a quote for your Abrasive Blasting project

Phone : (07) 5589 9303 or (07) 5589 2746 Mobile 0429 468 631

Steel Grit Media

Steel Grit blasting is the most widely used process for cleaning, stripping and removing rust from metal surfaces. The grade or size of the grit determine the ultimate finish. Steel grit is a cast steel angular grit produced by crushing specially heat treated oversize shot pellets. Its behaviour in service depends on hardness - a characteristic readily modified by suitable heat treatment. We typically use a GL 40 Steel Grit (about 0.5mm), which is harder than the GP Steel Grit, and it is particularly suited to heavy descaling and surface preparation requirements. GL steel grit cleans rapidly to give a clean finish to all surfaces. 

Our expert staff can determine the most appropriate method to suit your particular application and desired finish.  

Crushed Glass Media

Crushed Glass Media is a 100% recycled material.  The angular particles in crushed glass allow for aggressive surface profiling and removal of coatings such as epoxy, paint, alkyds, vinyl, polyurea, coal tar and elastomers. Crushed Glass Grit is much lighter weight than many slags, allowing for increased consumption efficiency and production time - up to 30-50% less glass grit used. 

Steel Grit Media Crushed Glass Media


NOTE:
We also have our Industrial Coatings facility right next door to the blasting unit for prompt painting of blasted items, and a Steel Fabrication facility for any repairs or modification that may be required.



Contact Details and Location

Contact: Peter Freeman (Abrasive Blasting & Industrial Coatings - Gold Coast Manager)

Office/Workshop - Davall Street, Currumbin, Gold Coast, Queensland 4223

Correspondence - PO Box 8 Currumbin, Gold Coast, Queensland 4223

Neumann Contractors - Abrasive Blasting Facility is located in the Neumann complex in Currumbin, on the Gold Coast, Link to Google Map


NOTE: SANDBLASTING, Abrasive Blasting is often referred to as Sandblasting. Sandblasting is a very general term used to describe the act of propelling very fine bits of material at high-velocity to clean or etch a surface. The term "Sandblasting" is still often mistakenly used to describe other, now more commonly used and better forms of Abrasive Blasting. Find out more about the term "Sandblasting"....


Workplace Health & Safety - Abrasive Blasting

The health and safety of our people is of the highest priority and cannot be compromised. Our objective is to have a workplace free of incidents and injuries.

Neumann Contractors is committed to maintaining a safe and healthy working environment for all employees and others, and the continuous improvement of occupational health and safety in all areas of the Company’s activities.

Neumann Contractors - Abrasive Blasting fully complies with:


Australian Standards

Neumann Contractors - Abrasive Blasting follows all applicable Australian Standards in all its abrasive blasting and associated activities.

AS1627.4 - Metal finishing - Preparation and pretreatment of surfaces - Part 4: Abrasive blast cleaning of steel specifies abrasive blast methods for the preparation of steel surfaces before coating with paints and related products.  All Neumann Contractors personnel are competent and suitable trained, qualified and supervised. 


Rust Grades and Classes of Blast Cleaning

Rust Grades - According to AS 1727.9 - Metal finishing - Preparation and pretreatment of surfaces - Pictorial surface preparation standards for painting steel surfaces, there are four initial rust grades, depending on the amount of mill scale and rust.  The worst grade of rust that is evident on the steel surface is recorded and treated accordingly.  The four Rust Grades are:     

GRADE A
Steel surface covered completely with adherent mill scale and with little if any rust.


GRADE B
Steel surface, which has begun to rust and from which the mill scale has begun to flake.


GRADE C
Steel surface on which the mill scale has rusted away or from which it can be scraped, but with little pitting visible to the naked eye.    
GRADE D
Steel surface on which the mill scale has rusted away and on which considerable pitting is visible to the naked eye.

Classes of Blast Cleaning (Abrasive Blasting) - As defined in AS 1727.9 - Metal finishing - Preparation and pretreatment of surfaces - pictorial surface preparation standards for painting steel surfaces, there are also four classes of Blast Cleaning, which are:

Sa 1 (Brush Blast)
Light blast cleaning. When viewed without magnification, the surface shall be free from visible oil, grease and dirt, and from poorly adhering mill scale, rust, paint coatings and foreign matter. The appearance corresponds to the prints designated Sa 1 in AS 1627.9.NOTE: Mill scale, rust or paint coating is considered to be poorly adhering if it can be removed by lifting with a blunt putty knife.

Sa 2 (Commercial Blast)
Thorough blast cleaning. When viewed without magnification, the surface shall be free from visible oil, grease and dirt, and shall be free from most mill scale, rust, paint coatings and foreign matter. Any residual contamination shall be firmly adhering (see note to Sa 1). It corresponds to the appearance of the prints designated Sa 2 in AS 1627.9.


Sa 2½ (Near White Metal)
Very thorough blast cleaning. When viewed without magnification, the surface shall be free from visible oil, grease and dirt, and shall be free from mill scale, rust, paint coatings and foreign matter. Any remaining contamination shall show only as slight stains in the form of spots or stripes and correspond to the prints designated Sa 2½ in AS 1627.9.



Sa 3 (White Metal)
Blast cleaning to visually clean steel. When viewed without magnification, the surface shall be free from visible oil, grease and dirt, and shall be free from mill scale, rust, paint coating and foreign matter. It shall then have a uniform metallic colour and correspond to the prints designated Sa 3 in AS 1627.9.




Note: The images shown above are indicative only, they show the results of abrasive blasting to Grade C rusted steel surfaces. Neumann Contractors - Abrasive Blasting predominately perform abrasive blasting services to a class Sa 2½ (Near White Metal) and Sa 3 (White Metal)

What is Sandblasting?

The Term "Sand" in Sandblasting:    Sandblasting is a very general term which is used to describe the process of propelling very small bits of material at high speed to clean or etch a surface. Sand (silica sand, beach sand, river sand) used to be commonly used for sandblasting, hence the term "Sand Blasting", but silica sand breaks up easily causing large amounts of dust, which exposes the operator to silicosis, a debilitating  lung disease, which is caused by the extended inhalation of the dust created by the use of silica sand as a sandblasting media.  The use of silica sand as an abrasive media in sandblasting is banned in many countries, including Australia, and is now recognized world-wide as a Class 1 Carcinogen. 

Other Sandblasting Media:    However other materials can be safely used in place of silica sand. At Neumann Contractors - Abrasive Blasting, we predominately use steel grit for removing rust and layers of paint from thick metal surfaces, and crushed glass for lighter surface which could be damaged using other heavier media. Other types of media that are available includes: steel shot, steel grit, aluminium oxide, copper slag, crushed glass grit, glass beads, silicon carbide, plastic, pumice, corn cob, walnut shells, and many others.  But there are still dangers in inhaling the fine dust particles during the process.  Abrasive blasting or sandblasting is carefully controlled, and we always use alternate air supply, protective clothing, and proper ventilation when sandblasting.  For more info on the equipment we use see: Neumann Contractors - Equipment

The Process:    Very simply, the abrasive blasting (sandblasting) process consists of  three components: the abrasive media, compressed air, and a blasting nozzle.   At our Abrasive Blasting Facility in Currumbin we predominately use abarasive blasting (sandblsting) to clean metal objects of rust and paint prior to painting.  But sand blasting can also be used, by others for etching and small object cleaning.  

The History of Sandblasting:    The sandblasting process was first patented in the US in 1870, after the observation of how sand-laden winds affected objects they came in contact with, by Tilghmann a chemist from Philadelphia, who also invented the air compressor.  The 1870 patent by Tilghmann was described as:

" A shot stream hurled to high speed by a steam or a draught is used as a tool to cut the stone and other materials. If it is hurled to a lower speed, it is used to grind down and ornament the glass surface."

In 1872, Tilghmann went on to further patent:

"cut, drill, frost, smooth, pulverize and engrave stones, metals, glass, wood and other hard or solid materials; clean and level the surfaces of the molten or beaten articles, and remove slags, scales and any other residues; prepare metals with tinning, enamelling, or to be covered with metal substances or other."

1886 saw Gutmann build the first suction sandblasting machine.  He later patented the "compressed air sandblaster" in 1893.