Best Practices and Things to Know About Spray Paint

Photo by Mec Rawlings on Unsplash

Spray paint is one of those mediums which is both simple and quite complex all at once, because there are a host of factors to consider between pressing the cap and paint hitting your painting surface. In this article we hope to inform you about some of the best practices to observe whilst using spray paints, so that next time you pick up a spray can it should be smooth sailing. 

Best Practices when using spray paint:

Shake Well – If a can has not been used in a while the paint inside can settle at the bottom, and if you use it without shaking first you can end up with suboptimal coverage and a poor finish. Make sure you can hear the mixing ball bearing rattle when shaking the can to ensure the paint is mixed properly. Hold the can upside down to help with unseating the paint and tap the bottom of the can a few times to unseat the mixer if you cannot hear it rattling. Shake for about 15 seconds after you can hear the can rattle and that should be enough make sure everything is thoroughly mixed. 

Purge the Cap – After finishing using a colour hold the can upside down and spray for a few seconds until it sprays clear. This will knock out any paint left in the cap and helps to extend the life of a cap and also helps to prevent the nozzle clogging.

Clean and Prime – Before applying paint or primer to plastics, glass and hard glossy surfaces it is best to clean it of any surface dust then degrease it to ensure the best adhesion of your paint. Priming surfaces ensures a good adhesion for your paint and it is best done in two thin coats. An even layer of primer before painting will provide you with a good base for painting and a unified base colour to work on top of.

Movement and Coverage – Unless you are letting the paint pool and dribble for effect it is best to make sure you keep the spray can moving. Side to side or up and down motions will give you the best results in most cases when you require even coverage. If the first pass is patchy do not worry as it is better to lay down a few thin coats than it is to blast the area with a single heavy one. Less can go wrong and the overall result will look better.

Read the directions – An easy one to neglect but, when in doubt read through the directions for use on the side of the can and it should provide you with all the information you require like drying times for coats, how the paint finishes and other useful details.

 

Things To Be Aware Of:

Temperature and Humidity – These two factors can play havoc with how spray reacts when it leaves the can and hits the air in number ways. Firstly, when it comes to temperature if it is too cold sprays can might lose pressure and require warming through, while the paint condenses and spatters when you spray giving a spotty finish. Hot temperatures can be equally adverse, hot weather can lead to increased paint fluidity where the paint is more likely to run and pool more easily. If the humidity is very low (15% and under) the paint can end up drying whilst it is in the air, hitting the work surface with a chalkier finish and poorer adhesion. High humidity (85% and above) mainly causes paint to take much longer to dry and properly cure as the saturation of moisture in the air inhibits the drying time. It is suggested that when spray painting you do so on days where the temperature is between 10 and 35 degrees Celsius and where the ambient humidity is below 85% to get the best results.

Recoat Time – Something that is always worth bearing in mind is a spray can’s recoat time, that being the time you should allow between coats. This is useful to know particularly when using spray varnishes for example, as it can help you avoid having your varnish clouding or failing to dry properly. Check the directions for use on the side of the can you are using and you will find the drying times for that particular brand.

Over spray – As the name suggests this is when you get excess paint spraying over areas you do not want it to go. Over spray is managed easily enough, putting down newspaper or a dustsheet is good way of catching any overspray you might get when working on something like a canvas. Masking off areas of a piece such as a mural work or a canvas that you are currently working on, will allow you to spray over previously painted areas without covering the work there. Simply use a low tack masking tape and tape down newspaper over the area, ensure the edges are sealed and proof against any paint spraying underneath it.

 

Health and Safety:

Wear a Mask – It is generally considered best practice to wear a mask whilst using spray paints. Even when working outdoors where ventilation is not a concern, wearing a mask helps to keep you from breathing in aerosolised paint particles. When working inside this can be doubly important and we suggest that at the least you should use a basic dust mask to keep the worst of it out. If you intend to paint for prolonged periods of time then a proper painting rebreather with filters is definitely recommended, as they are designed to filter both paint particles and airborne fumes.

Ventilate Indoor Areas Well – If you are working with spray cans indoors then you should make sure the area is as well ventilated as possible. Open all the windows in the room or area, open doors and if you are able too then set up a fan to help move the air. Wear a mask to help protect yourself from paint particles and, if at any point, you find yourself feeling unwell or getting a headache then stop immediately and leave the area and allow for any lingering fumes to disperse.

Gloves and Glasses – In addition to wearing a mask, protective eyewear and gloves are good to have to hand whilst using spray paints. Glasses will protect your eyes from airborne paint dust when working on large areas where particulates can build up in the surrounding air, and gloves will keep your hands clean and also help if you have a tendency towards sensitive skin. Gloves and glasses will give you an extra layer of safety against any potential irritants and generally keep you cleaner and safer overall.

Keep Away from Heat – Lastly and simply ensure you keep spray cans away from heat and fire as the propellant inside is highly flammable. It is best practice to also not leave cans exposed to direct sunlight in extreme temperatures either. Make sure you do not smoke whilst handling spray cans.