The present disclosure relates to blending microspheres in polyols, for example, as part of a process for making syntactic polyurethane. A system for providing a blend of microspheres dispersed in a polyol at a job site location, may include: a polyol receiving tank (110) configured to receive a polyol from an IBC (10), a dosing station (120) configured to provide a flow of fluidized microspheres, an in-line mixing machine (130) configured to mix the polyol from the polyol receiving tank with the flow of fluidized microspheres from the dosing station, and a conditioning tank (140) configured to receive the polyol -microsphere mixture. The in-line mixing machine may be a mobile, stand-alone blending unit configured for transportation to the job site location for mixing the polyol with the microspheres at the job site location.