The hydrodemolition surface preparation robots from Conjet AB/National Hydro use high-pressure water at 14,500 psi and repetitive motion to remove concrete, clean rebar and leave a roughed surface for the adhesion of new concrete without causing cracks or damaging the reinforcement. An alternative to jackhammers and hand-held waterjetting, standard models include the electric-powered 327 for areas where exhaust is a problem and the diesel-powered 557. Customized models 367 (electrical) and 437 (diesel) are available by special order. 517/223-0915; www.conjet.com.