Builder’s Bog is very stable with a very long shelf life at normal temperatures. Are you sure it has not just separated, with liquids at the bottom of the can? The special lightweight components can float up and form a stiff crust on the surface. Please put a sick or mixing blade right to the bottom of the can to investigate and stir it if found to be separated. If it really has thickened, there are no solvents in it and it has probably started to gel chemically. You could add a small amount of a polyester resin which will thin it.

If you email me the batch number on the small white stiker under the overcap, I will look up our retained sample of the same batch. Better would be to return it to your retailer for exchange or a credit, which our Australian agent Tradeware will be happy to make.

Your case is very unusual, and I would appreciate receiving your batch number.

Regards

Stuart Jordan
Managing Director
Chemical Specialties ltd
(24.3.2020)