- Joined
- Jul 27, 2012
- Messages
- 3,094
- Reaction score
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- Location
- Brisbane - Australia
- My Car
- 1973 Mustang Convertible
Hi to all,
INTRO.
Aerosol paint cans/rattle cans/paint bombs/pressure pack paint cans have been around for a long time now. (kicked in around the early Sixties i believe) Over the decades of buying them and using them, i have developed a love/hate relationship with them. There can be no denying that these products serve and fulfill certain painting requirements for the painting public, and they do them fairly well, and so they have proven to stay being quite popular with the consuming public over the decades. This can be demonstrated for example with the enormous impact that U Tube videos have had around the World with people uploading various videos and using rattle cans to paint their various projects that they are working on. The rattle can tends to be their go to weapon of choice, and so rattle cans seems to be the darling of the UTube set these days. Being a professional auto spray painter for most of my adult life, i too have used rattle cans for many various projects over the decades and still buy and use them present day. So what's my beef with rattle paint cans?
RATTLE CANS COMPARED TO CONVENTIONAL AUTO SPRAY GUNS.
The main catagories of auto refinish spray guns these days are gravity feed and suction feed guns. Gravity feed guns comes in styles such as HVLP and conventional style set ups. They all work on a similar principal where auto paint is mixed or reduced with a thinning material, or maybe a hardener added, and shot through the spray gun between 25 and 50 psi. This spray system through correct atomisation and transfer efficiency rate allows the correct amount of paint to be delivered to the substrate being painted. This paint is delivered coat by coat to the substrate to end up with a decent or good paint film thickness or buildup. Getting the right amount of paint thickness or buildup is very important to the end out come of your job you are working on for many reasons.
In comparison, when we look at rattle can performance, we see a different picture in regards to the way or manner the paint is applied and the paint film thickness achieved, compared to an auto spray gun. The main floor with rattle can spraying is the volume of paint coming out of the spray tip. A rattle can cannot compete with an auto spray gun in relation to volume of paint being delivered, the viscosity of the paint being delivered, the fan pattern of the paint being delivered. The problem is that in order to drive the paint out of a rattle can and get atomised correctly, it has to be thinned down dramatically with thinning agents and propellants. This brings about an end result of the paint being too thin, which introduces negative results such as excessive solvent penetration, solvent boiling, bad solvent substrate reactions, like frying up, wrinkling, crazing, checking, swelling etc. When we compare the coat by coat film build between the two, we see a dramatic difference. Generally speaking, you would need to apply around four or so coats of rattle can paint to one coat of tinned/ reduced auto paint. So you never really end up getting a decent or proper amount of rattle can paint on what you are painting. For example, lets say i'm shooting a car door in Acrylic Lacquer. I would need to apply around five or so color coats to achieve a decent paint film build that would withstand any cutting and polishing later on. SO WITH THE COMPARISON FILM BUILD RATIO OF RATTLE CAN TO AUTO GUN, YOU WOULD NEED TO APPLY AROUND 25 COATS OF RATTLE CAN PAINT TO END UP WITH THE CORRECT FILM BUILD NEEDED.Tinned auto paint/ thinner is expensive to buy, but so are rattle cans. When you compare the cost between the two and the performance between the two, the rattle can thing gets to be quite expensive as well as the tinned paint.
Recent rattle can technology has improved with the invention of using genuine two pack paints in rattle cans. They consist of two separate chambers, one holding the paint and another the catalyst or hardener. When ready to use or apply the paint material, you simply push the bottom of the can into the top section, which punctures the top chamber, and allows the hardener to be mixed in with the paint. Shake well and you're ready to go. Like all genuine two pack paint systems, the rattle can has limited pot life before it goes hard in the can. You can now buy these two pack rattle cans for solid colors, clean clears, primers, and epoxy primers as well. I have used only the two pack clear paint, and found it to be fairly decent all 'round, ( fan pattern, viscosity, atomisation and flow out etc) but in overall performance, it still does not compare with shooting through an auto spray gun. I have not used the primers or solid colors, so i can't speak with any experience there sorry. Also, on the point of genuine two pack paints, i have seen some rattle can products that state their paint is an epoxy type paint. This is false and misleading if the rattle can is sold as a one pack product. Single pack paint products such as lacquers, air dry enamels, putties, primers, metallics are just that. Genuine two pack products such as epoxies, urathanes, or any product that is catalysed with a hardener is just that. You can't have a one pack epoxy product.
Finally, here is a short list of the pluses and minuses of the two paint systems (i'm sure the Forum guys can think of others)..........................................
1. RATTLE CAN PLUSES.
Fast, handy, portable and convenient, ready to use, simple to use, requires minimal gun technique practice, great for small spray and touch up jobs, no mixing of paint and thinners, mostly quick drying times, good variety of color selections, no worries with buying expensive spray gun equipment, no worries with power bills running compressors, no worries with air lines getting in your way, very little fume or over spray produced, so good for confined areas, no need to wear a spray mask, but you really should anyway, minimal easy clean up, decent shelf life for single pack products.
RATTLE CAN MINUSES.
Poor atomisation, poor volume (amount)of paint delivered to the substrate, poor viscosity of paint delivered to the substrate (the paint medium is too thin and is full of solvents and propellants, which equates to a high solvent to paint ratio, which leads to many potential paint application problems occurring through the spraying process, the spray tip must be cleaned after each use, or tip clogging problems can occur, quality of product varies greatly in regards problems arising such as a new can that fails to release any paint at all from the tip, a used can that even with tip properly cleaned after use, refuses to release any more paint, a new tip that allows the paint to splutter out and not atomise properly, seeing some UTubers attempting to take on large spray jobs with rattle cans, such as the complete repainting of a full classic car chassis in black lacquer, really?
2. SPRAY GUN PLUSES.
Allows the correct amount of paint (film build) to be applied to the substrate, allows the correct thinning ratio to be brought into play for little to no solvent reaction issues, comes in a multitude of paint types, varieties, effects, colors, that the rattle scene can't match, allows a custom mix of viscosities for varied applications, generally has a longer field life than rattle cans do (due mainly to lesser solvents used and greater film build qualities),
with correct number of coats, wet color sanding and cutting and polishing can be brought into play for a beautiful finish.
SPRAY GUN MINUSES.
Expensive to set yourself up with equipment such as guns , compressors, and all the gear you need to pull off a good spray job, storage of flammable goods can be a problem with fire issues and insurance claims, the need for decent shop spraying conditions comes into play to produce a decent job, especially with two pack paints, health and safety issues kicks in when shooting through spray guns, produces a lot of fume and over spray, creates the need for more masking up of the job, cleaning up equipment is a pain in the butt, disposal of chemicals can be a problem, the rising costs of auto paints , especially two pack products, requires a high skill level to spray out properly(gun technique etc), hence, a decent learning curve needed to deliver a decent result.
So there you go - that's my take on the rattle can thing. It would be good to see rattle can technology improve in the future to deliver better results than they do today. The intro of the two pack rattle cans, as well as getting them refilled with your choice of paint, is certainly a big step forward. I will still make use of them in the forseeable future, but only use them for a small amount of limited applications, as for me, the rattle can thing is a very limited way of applying paint correctly.
Hope this write up was of good help to the Forum members.
Greg.
INTRO.
Aerosol paint cans/rattle cans/paint bombs/pressure pack paint cans have been around for a long time now. (kicked in around the early Sixties i believe) Over the decades of buying them and using them, i have developed a love/hate relationship with them. There can be no denying that these products serve and fulfill certain painting requirements for the painting public, and they do them fairly well, and so they have proven to stay being quite popular with the consuming public over the decades. This can be demonstrated for example with the enormous impact that U Tube videos have had around the World with people uploading various videos and using rattle cans to paint their various projects that they are working on. The rattle can tends to be their go to weapon of choice, and so rattle cans seems to be the darling of the UTube set these days. Being a professional auto spray painter for most of my adult life, i too have used rattle cans for many various projects over the decades and still buy and use them present day. So what's my beef with rattle paint cans?
RATTLE CANS COMPARED TO CONVENTIONAL AUTO SPRAY GUNS.
The main catagories of auto refinish spray guns these days are gravity feed and suction feed guns. Gravity feed guns comes in styles such as HVLP and conventional style set ups. They all work on a similar principal where auto paint is mixed or reduced with a thinning material, or maybe a hardener added, and shot through the spray gun between 25 and 50 psi. This spray system through correct atomisation and transfer efficiency rate allows the correct amount of paint to be delivered to the substrate being painted. This paint is delivered coat by coat to the substrate to end up with a decent or good paint film thickness or buildup. Getting the right amount of paint thickness or buildup is very important to the end out come of your job you are working on for many reasons.
In comparison, when we look at rattle can performance, we see a different picture in regards to the way or manner the paint is applied and the paint film thickness achieved, compared to an auto spray gun. The main floor with rattle can spraying is the volume of paint coming out of the spray tip. A rattle can cannot compete with an auto spray gun in relation to volume of paint being delivered, the viscosity of the paint being delivered, the fan pattern of the paint being delivered. The problem is that in order to drive the paint out of a rattle can and get atomised correctly, it has to be thinned down dramatically with thinning agents and propellants. This brings about an end result of the paint being too thin, which introduces negative results such as excessive solvent penetration, solvent boiling, bad solvent substrate reactions, like frying up, wrinkling, crazing, checking, swelling etc. When we compare the coat by coat film build between the two, we see a dramatic difference. Generally speaking, you would need to apply around four or so coats of rattle can paint to one coat of tinned/ reduced auto paint. So you never really end up getting a decent or proper amount of rattle can paint on what you are painting. For example, lets say i'm shooting a car door in Acrylic Lacquer. I would need to apply around five or so color coats to achieve a decent paint film build that would withstand any cutting and polishing later on. SO WITH THE COMPARISON FILM BUILD RATIO OF RATTLE CAN TO AUTO GUN, YOU WOULD NEED TO APPLY AROUND 25 COATS OF RATTLE CAN PAINT TO END UP WITH THE CORRECT FILM BUILD NEEDED.Tinned auto paint/ thinner is expensive to buy, but so are rattle cans. When you compare the cost between the two and the performance between the two, the rattle can thing gets to be quite expensive as well as the tinned paint.
Recent rattle can technology has improved with the invention of using genuine two pack paints in rattle cans. They consist of two separate chambers, one holding the paint and another the catalyst or hardener. When ready to use or apply the paint material, you simply push the bottom of the can into the top section, which punctures the top chamber, and allows the hardener to be mixed in with the paint. Shake well and you're ready to go. Like all genuine two pack paint systems, the rattle can has limited pot life before it goes hard in the can. You can now buy these two pack rattle cans for solid colors, clean clears, primers, and epoxy primers as well. I have used only the two pack clear paint, and found it to be fairly decent all 'round, ( fan pattern, viscosity, atomisation and flow out etc) but in overall performance, it still does not compare with shooting through an auto spray gun. I have not used the primers or solid colors, so i can't speak with any experience there sorry. Also, on the point of genuine two pack paints, i have seen some rattle can products that state their paint is an epoxy type paint. This is false and misleading if the rattle can is sold as a one pack product. Single pack paint products such as lacquers, air dry enamels, putties, primers, metallics are just that. Genuine two pack products such as epoxies, urathanes, or any product that is catalysed with a hardener is just that. You can't have a one pack epoxy product.
Finally, here is a short list of the pluses and minuses of the two paint systems (i'm sure the Forum guys can think of others)..........................................
1. RATTLE CAN PLUSES.
Fast, handy, portable and convenient, ready to use, simple to use, requires minimal gun technique practice, great for small spray and touch up jobs, no mixing of paint and thinners, mostly quick drying times, good variety of color selections, no worries with buying expensive spray gun equipment, no worries with power bills running compressors, no worries with air lines getting in your way, very little fume or over spray produced, so good for confined areas, no need to wear a spray mask, but you really should anyway, minimal easy clean up, decent shelf life for single pack products.
RATTLE CAN MINUSES.
Poor atomisation, poor volume (amount)of paint delivered to the substrate, poor viscosity of paint delivered to the substrate (the paint medium is too thin and is full of solvents and propellants, which equates to a high solvent to paint ratio, which leads to many potential paint application problems occurring through the spraying process, the spray tip must be cleaned after each use, or tip clogging problems can occur, quality of product varies greatly in regards problems arising such as a new can that fails to release any paint at all from the tip, a used can that even with tip properly cleaned after use, refuses to release any more paint, a new tip that allows the paint to splutter out and not atomise properly, seeing some UTubers attempting to take on large spray jobs with rattle cans, such as the complete repainting of a full classic car chassis in black lacquer, really?
2. SPRAY GUN PLUSES.
Allows the correct amount of paint (film build) to be applied to the substrate, allows the correct thinning ratio to be brought into play for little to no solvent reaction issues, comes in a multitude of paint types, varieties, effects, colors, that the rattle scene can't match, allows a custom mix of viscosities for varied applications, generally has a longer field life than rattle cans do (due mainly to lesser solvents used and greater film build qualities),
with correct number of coats, wet color sanding and cutting and polishing can be brought into play for a beautiful finish.
SPRAY GUN MINUSES.
Expensive to set yourself up with equipment such as guns , compressors, and all the gear you need to pull off a good spray job, storage of flammable goods can be a problem with fire issues and insurance claims, the need for decent shop spraying conditions comes into play to produce a decent job, especially with two pack paints, health and safety issues kicks in when shooting through spray guns, produces a lot of fume and over spray, creates the need for more masking up of the job, cleaning up equipment is a pain in the butt, disposal of chemicals can be a problem, the rising costs of auto paints , especially two pack products, requires a high skill level to spray out properly(gun technique etc), hence, a decent learning curve needed to deliver a decent result.
So there you go - that's my take on the rattle can thing. It would be good to see rattle can technology improve in the future to deliver better results than they do today. The intro of the two pack rattle cans, as well as getting them refilled with your choice of paint, is certainly a big step forward. I will still make use of them in the forseeable future, but only use them for a small amount of limited applications, as for me, the rattle can thing is a very limited way of applying paint correctly.
Hope this write up was of good help to the Forum members.
Greg.
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