The best way to use aerosol varnishes
1. Try not to store aerosols below 15'C (59'F). If they have been stored around this temperature do not use them until they come up room temperature again. This is because all aerosols contain a mix of product and propellant and at lower temperatures the products wants to "drop out of solution" and so could either block the nozzle, or worse, come out of the nozzle as "blobs of product" which then fall on the work itself.
2. Always shake the container vigorously before use to ensure the contents are homogenous.
3. Always hold the container upside and spray for a couple of seconds - this will send a spray of propellant only out of the nozzle and clear it
4. Always do this at the end of use as well to clear the nozzle of material build up.
5. Be careful if using the container extensively over a short period of time as the contents temperature will drop with a potential for the product to "drop out of solution", this applies to all aerosols but is only likely to be noticed during extensive use.
6. Always spray with the can almost vertical and allow the contents to "cascade onto the work".
7. When spraying, the can should be held at least 25-30cm (10-12 inches) away from the work.
8. Mount the work onto a support that you don’t mind spoiling and spray side to side beyond the extremities of the work to ensure full coverage.
9. For porous, unprimed surfaces such as card, canvas, hardboard or plaster etc. apply a thin layer of gloss varnish before applying any matt or satin varnish.