Bigger tins are better as the cooling effect is a lot less.
What happens is that as the gas evaporates the higher energy molecules are being removed from the equation so the resultant average energy level decreases and the temperature drops. As the temperature drops the chemistry gives way to physics and the rate of evaporation of the gas reduces, thereby eventually dropping the pressure.
The bigger the tin the less this happens. Other ways of avoiding it are to warm the tin in warm water but that can be a bit hit and miss and cause too high a pressure if you get it wrong and the paint starts to dry too quickly.
What I always did was learn to live with it. After a period of painting give it a rest, clean the nozzle, and let the temperature rise again. You will soon get the hang of how long you have before you need to stop and with small models you won't have a problem.
Consistency is always described as "Milky", which is a bit vauge but when you swirl it around the jar you should see it adhere to the sides and run down sort of like a milk would look. Try it first though on a test peice. In fact try quite a few jars of paint on test peices to get the feel of what it will do, how long the paint will last, gas pressure etc..etc..
Richard has it in a nutshell, drink a glass of milk and have a look!! |