URP 301 should not be used in this fashion. You must use LW+ chemical if you want to use it with mortar or RCC. URP 301 should only be mixed with cement and then applied with brush. Please use the chemicals for their rightful purpose and mix in proper ratio as per directions or else there is no point in using it.
This is not the correct method of using Dr. Fixit URP. It should only be mixed with cement 1: 1.5 ratio and applied with brush. You can use this process for LW+ only.