Do you need adhesive for thermostat gaskets?

In most cases, no adhesive is needed for installing thermostat gaskets. Thermostat gaskets are designed to create a seal between the thermostat housing and the engine block, and relying on the pressure from the housing bolts is sufficient to ensure this. However, it's always a good idea to refer to the specific manufacturer's guidelines for the model you're working on, as some gaskets may require an adhesive sealant.