Abstract
This technical paper introduces a newly developed surface preparation process termed bristle blasting, which utilizes a specially designed rotary power tool for simultaneously removing corrosion and generating an anchor profile. The process derives its name from sharp, hardened bristle tips which, upon striking the corroded surface, immediately retract, thereby creating a micro-indentation that both removes corrosion and simultaneously exposes fresh subsurface material. Consequently, the repeated collision/retraction of bristle tips with the corroded surface leads to a surface cleanliness and anchor profile that resembles surface prepared by grit blasting processes.
Performance of the bristle blasting process is evaluated within the context of an application that involves cleaning/texturing severely corroded API 5L piping, which is commonly used for onshore/offshore petroleum transport applications. The results demonstrate that surface cleanliness and texture achieved via bristle blasting tools is on a par with grit blasting processes. That is, a near-white metal and white metal appearance of cleaned surfaces is routinely obtained, and is accompanied by an average peak-to-valley surface texture (Rz, microns) given by: 83 ≥ Rz ≥ 62. Finally, careful study indicates that bristle blasting tools can remove corrosion at a rate in excess of one square meter per hour throughout the duration of tool life.
