Well i am trying to re point the house and have successfully raked out the old mortar. but i want it re doing in red mastic i have done a test patch with some ready made trowel mastic and it seems to be taking ages to dry like 4 days and it only just seems to have changed consistency but is still to soft for my liking is this normal? i need to get on with this job but this could end in a disaster if its wrong. which gets me thinking if its going to set this soft will it make the walls to week.....