A costomer brougt a few small parts to be painted with his ppg deltron 2000 DBC. He also brought some omni drr 1185. the reducer is several yrs. old. Seems like I remember this stuff having a limited shelf life after being opened. I have all temps of SPI reducer and Ms and universal activator. How should I mix this stuff.I used to have a ppg tech web site, but must have deleted it. Thanks, help if ya can Sarge