Near the beginning of his career, he worked with Andrew Weatherall on remixes of Meat Beat Manifesto, remixed for Saint Etienne, U2 and others. He was still a teen when working on the first few albums by The Orb. Thrash was with The Orb for less than 5 years, from around 1990 to the end of 1995. He appeared on the Orb albums and the many remixes they did during this period, including the album FFWD, a collaboration with Robert Fripp that is credited to Fripp, Thomas Fehlmann, Weston, and Alex Paterson.
He also worked with Fortran 5 on their first album Blues.
Weston and Paterson, along with Robert Fripp and Thomas Fehlmann worked on the FFWD. Soon after the release of FFWD in August 1994, Weston suddenly quit The Orb to pursue his own projects. Paterson claimed that Weston's departure was due to Weston's desire to have more control over The Orb's projects. However, in an interview with i-D, Weston reportedly attributed the split to Paterson, saying that Paterson "never did 50% of the work."