Methods for removing contaminants from a metal surface are called surface preparation.
Equipment to be used
Among the deoxidation processes, the application of the following has spread in construction practice and job-site construction.
- Manual hammers as pre-cleaning devices (MSZ 1380), hand scrapers (rasketta), spinning-reel jackhammers, pneumatic hammers (VON-ARX),
- Manual grinding, wire brushing with abrasive cloth and abrasive paper (MSZ 4541 and 4542), steels,
- Machine grinding or manual and machine grinding, vibration abrasive when wire brushing, rotary grinders
- Rotary dial wire-brushes (OSBORN-system), abrading with corundum rotating dials (MSZ 4501)
- Compressed air VON-ARX machine cleaning (with steel needles)
- Arrow beam blasting, sand blasting equipment with dry grains of sand and air engine granting the power (modern equipment) (picture 19)
In industrial practice, two types of adhesive dirt are removed during degreasing:
- Organic impurities such as oil, grease etc.,
- Dust or colloidal impurities such as dust, soot, sludge etc.,
Using some methods adhesive impurities can also be removed in go.
Degreasing is being regulated in MSZ 1891/3-71. national standard and in KGMI 22.599-675 and 22.602/1. sectoral technical guidelines and it also includes recommendations for the best degree of purity at certain technologies.
Taking the construction work area and the local conditions and features into consideration, the following degreasing procedures may be used:
- wash-down with aliphatic hydrocarbons
- Hot water and steam jets or chemical combinations with high pressure washing equipment
- Wash-down with synthetic detergents and aqueous solution of emulsifiers