Roller Painting - More Options??

[Norm's Coupe]

Here's a possibility for more color options when painting the car with a roller. Don't know if it will work, but someone could try it if they wanted to. Maybe do it on some scrap steel first.

If you think about it, the Tremclad and other rust type paints everyone is talking about all are the same type base paint. Then everyone is mixing something like mineral spirits to it to make it flow better. Then applying in very thin coats until a good finish is accomplished. Somewhere between 6 and 8 coats. According to Hot Rod magazine, the amount of thinner mixed really didn't have to be exact to accomplish the same results.

If you look at regular automotive paints and engine paints, they can also be purchased in an enamel base. When you open a can of automotive paint it is also a little on the heavy side. Then you mix thinner/hardener to it to make it flow better and go through the spray gun. With that in mind, you should be able to mix less (or no) thinner with the automotive paints, then roll it too. As mentioned the only real purpose for the thinner is to make it thin enough to go through the gun and for faster drying. The paint will still cure if less or no hardener is mixed in, it will just take longer like the rust paints do. Plus, by mixing less hardener into it and slowing the cure time, the roller and brush marks should self heal more than it would as a fast dry.

I've never tried this with regular automotive paint. Just tossing the possibility around. However, if some of you can recall, there was a professional automotive painter on the TV show Tool Time years ago who painted cars using a rag as you would wood stain on wood and it looked great. So.....if he could do it with a rag, you should be able to do it with a roller.

That said. I have brushed on engine enamel that I bought from Bob Hirsch by the quart. That paint was also about $30 per quart including shipping cost. I followed instructions for brushing it on and did not use any thinner at all. The paint cured in about 24 hours. The label says it can be used on cast engines or bare metal parts. I also painted the transmission and the steel selector arms on the transmission with it. Later, I had already had my 4 original 16 inch wheels blasted and had painted those with automotive paint. However, since I did not buy a new tire for the spare, I never blasted it. One day just to make the spare look better in the trunk, I painted it with the Hirsch engine paint too. Since I considered it a temporary paint job, all I did was wipe off the dirt, then painted it with the left over Hirsch engine paint, without thinning the paint. I had that spare in the trunk for several years and no rust ever came back through the paint, and it was also nice and smooth, no brush marks. Now, according to the instructions on Hirsch paints, it says you need a primer on unpainted steel surfaces and to thin for use in a spray gun. It also says you do not need to thin for brushing the paint on.

My engine block and transmission were down to clean bare castings when painted. I applied two coats of paint on both using a foam brush. When finished the engine and transmission did have a nice sheen to them. Of course I did not try to get a good shine by wet sanding or polishing, but wonder what would happen if I did?? The Hirsch paint is also an enamel based paint. I can't try polishing or wet sanding that wheel now because I sold it after changing to 15 inch wheels.

Just thought I would toss this out there in case someone had a little left over automotive paint and wanted to try it with a roller. If it worked people would have a better selection of color. Don't know if it would work too well using a metallic paint though. That's because the metal flake may not come out even with a roller or brush. If you could keep the metal flake evenly suspended though while rolling, that paint should work too.

So.......who out there wants to be the explorer that has a little left over automotive paint. Doesn't matter if it's metallic or not. The metal flake may not come out even, but the test would be if you could roll it and get the same even flow results and finish as you do with the rust paints. Except for the mixing quantities of thinner, you would probably have to use the same application method of sanding between coats.

[Norm's Coupe]

An after thought about metallic paints.

For years (from 1968 until 2001) I also sold roof coatings and paints for flat built up roofs and metal roofs. In the mix we had aluminum roof coatings and paints. Of course the coating was a much heavier product than just the roof paint was. However, both the coating and paint had aluminum metal flake in it to give it the color.

Now, when you first opened a drum or 5 gallon pail it looked like a bunch of real thin brown liquid with a small amount of aluminum streaks running through it. We also furnished heavy duty spray equipment to apply it, or it could be brushed onto the roof surface. Application was the same for both the coating and paint. We always told the customer to stir thoroughly before applying. Then regardless of spraying or brushing either product the product looked like a brown coating when first applied. As both products cured the aluminum flake would float to the surface with the built in thinning agent as it cured, leaving a nice even aluminum color on the roof.

With that in mind, maybe it is possible to do the same thing with the automotive metallic paint. However, it would probably have to have less thinner so the paint would take longer to cure, giving the metal flake more time to rise to the surface.

[rearview]

you'd have to mix in the hardener... but no big deal. We touch up paint our machines with rollers and it's ok.... using urethane paint

[Plymouthy Adams]

Norm..the solvents in automotive finishes are such to allow a flash time in minutes..say on the average 12 to 18 minutes between ocats based on temp and humidity. The roll on results of the Tremclad/Rustoleum paint is directly porportional to the slow dry time..this allow for the paint to lay down. The oils used here is the slow agent...the mineral spirits is a thinner to those oil to allow a thinner more even coat to be applied. Of course you know this. Working with automotive grade paints you do not have the luxury of time..

AND................for those who wish to make their paint a bit more "durable" I have successfully added generic acrylic hardner to the Rustoleum topcoat for added hardness and brilliance in finish. The ratio is 4 parts paint to 1 part hardner, thin to "your" preferred viscosity dependent on applcation process...when spraying I use enamel reducer of automotive paint grade and throw in some silicone eliminator. Works for me..I normally use this for under body, engine compartments etc where the customer wants a gloss black durable finish. My generic harder of choice is EVERCOAT...please use a respirator when spraying..definitely use a respirator when adding the hardner to the mix.

[rearview]

Tim... wouldn't changing to a different temp range reducer fix that issue of short flash time? when spraying a large area, I was taught to change to a slower reducer to get better blends and melts.... or follow with a light spray of straight reducer to melt the surface and settle it.

[Plymouthy Adams]

The temperature difference of the fast, medium and slow reducers is still engineered around the 18 minute flash..for spraying the anser is yes, will not add significant time to flash for say roller application in my book..and it is a little know fact to most people and shops don't like to let the public know due to cost involved..but paint is still laying down for up to 30 days after spraying. DuPont Centari, topleading brand of enamel still reeks to high heaven if left in a enclosed garage 30 days later..the quickest paint on the market to my knowlege is Limco Supreme..color sanding and buffing is permissable after 16 hours dry time. It is my paint of choice for past 23 years.

[Norm's Coupe]

Tim,

Like I said, I'm just tossing this around and never tried it with automotive paint. If you use automotive paint straight from the can without a reducer, how long does it take to set up and cure to the touch?

[rearview]

Tim' date='

Like I said, I'm just tossing this around and never tried it with automotive paint. If you use automotive paint straight from the can without a reducer, how long does it take to set up and cure to the touch?[/quote']

Measure the time with a sundial

[Plymouthy Adams]

don't think I would use a sun-dial but will give you the benefit of a longer time as the mill thickness will be great and thus the "curing" time..but..even with this, the skin will be flashed fairly quickly....

The sanding of Tremclad and Rustoleum would not be something I would do without a very lengthy drying period...if I am priming a surface that has to be done in X-amount of time and such...never would I use the Rustoleum product..it needs to sit minimum 14 days..periods of sitting in the sun greatly helps the process. This primer is still "flowing" for about 3 days... As for the topcoat..if sprayed and using a hardner...then working the paint within a few days would be ok...reason is the mil thickness of the sprayed coat is more cosistant and thinner...the chances of a cured topcoat in short time is greatly improved.

[Norm's Coupe]

Well Tim, you may be right. However, I'm one of those people who always says, never say never until I've never tried. So, if no one else wants to try it I'll check around to see if anyone has a little auto paint laying around to test my theory. I think I do have a small amount in a quart can. It may not be any good though since it's about 10 or 12 years old. It's probably set up in that can by now. My brother in law may have some that is still good though. I will not use regular automotive paint hardener/reducer though. That would decrease dry time. To make it dry slower and increase dry time, I'll try just plain mineral spirits first since it drys slower.

Making it dry slower could also take away from the gloss finish. So, that could be a major drawback on a car finish. It will probably also make the finish softer than normal. However, a softer finish in my book is not all that bad. A softer finish will deflect more stones and dirt better and will not chip as easily. I know a lot of people like urethane or epoxy paints for durability. However, coat one piece of metal with urethane and one with a rubber coating. Let them both cure. Then try sandblasting both of them. The urethane finish will come off real nice. However, the one coated with rubber is going to take much longer to sandblast because the sand bounces off the rubber.