SPI’S Polar Accelerator may be used in any urethane or polyurethane clear to speed up the dry time. Used at the rate of 1-4 oz per mixed quart of clear this accelerator will not cause dieback or cause the clear to buff hard. SPI’S 900-4 may also be used in any 2K type urethane primer at the same rate. Keep in mind that accelerator will decrease pot life in any product. 2K Primer pot life should be watched closely.