Decrease your plaster setting times.

You might want to increase working time if you are spreading plaster over a large area.

For the retarder, dissolve 100 g in 1 litre of hot water and allow to cool, add 5 ml of this mixture per litre of water to be mixed with plaster. This will approximately double the setting time.

Setting times will vary a lot depending on the plaster so it’s important to test before adding to final mixes.

See also Plaster Accelerator to increase setting times if you want to clock off a little earlier.