Paint Will Not Dry

The possibilities are many.

You may be seeing a reaction between the paint/paint solvents and the plasticizers in the rubber underneath. Something is combining that shouldn't. Not knowing the chemicals involved, that's guess # 1.

If the paint just has to be used, try an intermediate paint (primer if you will) that is specifically made to paint rubbers/elastomers.

Last resort, heat gun a sample to see if you can ever get it to dry.

Or, use another paint made for rubber and be done with it.

Morning Lyn,

Yup baking them like HOT will eventually dry it off. But a Pain!

But I just now did try the intermediate barrier layer idea. I took their sealer and applied it to it, will let it dry and they try the paint over it.

Joe

Acetone dissolves rubber....you need an acrylic paint..or possibly dye...

https://www.quora.com/What-are-the-best-ways-to-paint-rubber

Rubber is a polymer, acetone is a solvent...

https://www.britannica.com/science/polyisoprene

We've run into the trap of assumption.

SE assumes the unknown when searching for a problem that is not defined.

"Rubber" is a generic term for anything that is flexible, or "squishy." That includes thousands of different formulations of the substance.

This particular paint is OK for plastics, but it is not recommended for "rubber," that I could see.

Good luck.

Problems are solved one step at a time, assumption is a key troubleshooting tool...Starting with the most likely scenario, one must test each theory until satisfactory results are achieved...Working in the field, one does not always have the luxury of detailed analysis, you must learn to think on your feet... ...we'll leave it to the OP to choose which information best serves his or her purpose....

The Ball manufacturer says it is Buna-N,

But the same exact thing happens with the paint on the plastic/rubber of an extension cord.

like this kind,

Buna-N is not compatible with acetone...

Thing is what is actually happening? When removing the paint, Using a zip strip like remover, the surface of the ball seems to have no surface difference at all. Yet the paint remains sticky like almost forever.

Interesting.

So what might work?

Joe

Nope too thick he he he where is Billy Mays when ya need him eh?

But wait! That's not all!

https://www.flexsealproducts.com/wp-content/uploads/2017/02/colors.mp4

OK there's a guy that swears this stuff works well, no cracking....

Decoart Non-Prep Metal paint

I can't say, but if it was me I would give it a try...

I've had this and it turned out to be that the surface I was painting over was solid non-porous, so wouldn't allow the back of the paint to cure, My solution was to strip off the paint & coat the surface with a etching solution, then to repaint. I'm not saying this is your solution but it's worth exploring.

Bazzer

The non porous I don't think is it. Because I use the same paint on Plain steel, and Nickel plated steel, and it is dry enough to touch in 10 to 15 minutes.

Just on this "Rubber" Buna-N and whatever say a standard el-cheapo $1.38 6 foot extension cord is made from, it just never seems to dry.

That is correct what contributors say: there is a (paint) solvent plasticization effect.

Solvent parameter is higher with rubber than paint; therefore solvent remains at rubber-paint interface.

TEST: make cold the rubber surface and apply hot paint. Paint solvent should evaporate faster and rubber interaction should decreases; paint drying should increase.

The only problem with making it cold here is humidity, Now I'll have a Blooming happen because of the moisture. :-(

Joe

Well, an alternative way could be to saturate the rubber surface using a non-solvent such as alcohol, next apply paint.

explain this alcohol idea more.

I have some here I use to clean the brushes when I use the sealer on the wood.

But it dries FAST!

Is the idea to soak the rubber in it for a while, then take it out and 30 seconds later it's dry then apply the paint before any of the rubber chemicals leach back to the surface?

Or what is the idea?

IDEA: To alternate (modify) the rubber surface using a polar non-solvent to prevent interactions with the paint solvent (which swollen the rubber). So, it is valid to think in other ones.

Therefore the rubber temperature should be decrease due to it is a strong parameter increasing solubility.

I don't think you understand the chemistry of IPA. Or how spray paint "dries".

Isopropyl alcohol is an isomer of 1-PROPANOL. It is a colorless liquid having disinfectant properties. It is used in the manufacture of acetone and its derivatives and as a solvent.

Alcohol is routinely used as a cleaning (solvent) for electronics to remove flux and contaminates.

I have to disagree with everything you said.

I wonder if something like this would help?

https://www.sherwin-williams.com/homeowners/products/crown-japan-drier

Joe

You could just buy colored balls...

Trying to find tight tolerance ones, is the issue. the only tight tolerance ones are black.

These precision Delrin balls come in colors...

https://www.precisionplasticball.com/1-in-1-white-delrin-plastic-resin-balls/

Very Nice Solar Eagle will contact them!

Thanks!

Joe

I'm surprised that no-one has yet suggested to "contact the manufacturer" of the paint. As already suggested, it might seem the solvent is absorbing into the article being panted and then VERY slowly being released.

Another option is that it is chemically reacting (either with the substrate material or mould release) and changing into a stable and tacky "grease" that will never really dry.

If it's absorbed solvent, then maybe a light vacuum would accelerate the solvent release, but don't rush as this could also cause delamination.

Yeah No one suggested it, But already done, their reply....

Hello Joe,

Unfortunately, this does for all of our products that when it comes to rubber or rubber like materials our products have a reaction to the rubber and our paint will never dry and will remain tacky or sticky. The solvents in our coating because of the materials in the rubber are unable to escape out of the paint even with good airflow, perfect temperatures, and humidity. Using Denatured Alcohol doesn't work to help the coating dry either and anytime its used on rubber it has to be removed. our brand team has been working on this for a while but have not come up with a coating that would work but also have the durability that our products are known for.

Thank you for your interest in Rustoleum products. We hope this information was helpful. Please do not hesitate to contact us if any additional assistance is needed.

Regards,

Jim H

It looks like you have a case of plasticiser migration. The plasticiser migrates into the drying paint film and makes it tacky. We usually block this with a layer of alcohol based lacquer, which blocks the migration

Quit watching it.

HA! Good one!

No wonder I never get hot water for Tea, I have the same problem, Go figure!

Had the same problem with my ink jet printer when using ecosolvent inks. Ultimately found that the solvent in the ink was sucking the plasticiser out of the (new) CISS / inktank system, so would not dry. After a month it would be ok, but after a few months the PVC tubes would become hard and break - ink everywhere!

Suggest you try cleaning the substrate with metho, and also naptha - may help it cure-

Your answer lies under the description of "Hansen parameters". There are a few other ways to describe it, but that's my personal preference. Hansen parameters are a range of dispersion, intermolecular and hydrogen bonding forces for different molecules. They also allow you to predict what effect a combination of different chemicals will have on solubility factors.

So, what this means is that your problem is not that the paints are incompatible with the rubber, it's that they ARE compatible!!! Or at least that some of the polymers and/ or solvents in the paint have an affinity for the rubber.

This means that some of the paint components may migrate into the rubber, which could potentially slow down any curing reactions (not sure if this applies to Rustoleum) and also that they can slowly migrate back into the paint as it dries, leaving it tacky. The other possibility is that some shorter chain rubber molecules are being soaked up by the coating with a similar effect.

In either case it does not mean the one is necessarily dissolving the other- it's preferential migration. As Lyn said, treating it first with a solvent such as IPA will have next to no effect other than cleaning it for painting. You DON'T want to use a solvent that will actually soak in as that will make the tacking problem even worse. Maybe shellac....?

I have run across exactly the same problem over soft plastic light housings of modern production for antique vehicle/aircraft restoration. First solution that worked, but was time consuming, was to dry-spray. A process of increasing the distance between spray nozzle and the object being painted. Just enough tack left in the paint particle to stick but not flow out. Much like a thin fine spatter coat.

Let dry to the point of no tack. About 10 to 20 minutes. Second coat the same way. wet enough to stick but no flow out. Let dry to the no-tack point, then cover with a proper wet coat that flows giving you the final look you want. Final dry time was correct for the paint.

We also did some mixing using a very quick flashing solvent. Sped things up a bit but control became a problem.

Ours was as durable as we expected, but the time required made us look for another method.

The other method was using that Japan drier, or equivalent, at a slightly higher mix ratio than directed. The excess drier allowed us to spray our normal wet coat. And we got drying with no tack after a few hours. My chemist's theory was that the drier did the same thing to the leached plasticizer as it did to the paint.

Bond and elasticity of the paint was as it needed to be...and more important, no tack! Test it!

Your solution may be a modified acrylic.

Being the "Rustoleum" Rattle cans, Can the japan drier be applied after spraying?

if yes how soon?

Right away. or after to the does not dry tacky point?

Such a method might work (spraying the drier after the fact) and I have tried such solutions in desperation, but satisfactory results are less than likely!

Rattle cans are easy, but the Rustoleum paint is available in non-aerosol pints, quarts, and gallons. And it appears that the solution is going to require a bit more chemistry.

I do understand the need for convenience and the desire to not have to clean up spray equipment. Been there. But, a spray-gun system, maybe just a heavy duty air-brush, is likely going to be necessary.

There are inexpensive dip-tube spray systems that use throwaway containers.

Did someone get caught "watching the paint dry"?

If you are just trying to color code the cord, have you considered colored electrical or duct/decorative vinyl tape wrapped around the end of the cable?

I'm not so worried about the cable, it's the balls that are the issue.

I have not read every word above but did not see this. it seems to me a primer coat should work as a barrier to prevent the plasticizers in the ball from coming in contact with your paint.

The regular "Rustoleum" primer is the same formula and also never dries.

BUT I may try a different based sealer, that is supposed to work with any topcoat.

Because it's Rustoleum. I know that sounds like a smartass response, but the truth is Rustoleum used to be a very good industrial paint. That is until it went to the Home Depot/ Lowe's/ Menards/ Walmart marketplace. The big changes were in the solvents formula and pigment to filler ratio. We make highend sculpture and even for small works and spot repairs Rustoleum stays on the stores' shelves. Yes, it goes on fine, but it has VERY poor durability or colorfastness in UV conditions. Try DulpiColor autopaints. Yes you will need multiple coats, but it has excellent durability and colorfastness in all conditions. As for your particular problem it's probably the solvents micro-corroding the neoprene/ vinyl jackets and then that corrosion product combining with the chemical components of the paint. If you are so inclined The Getty Center has a great book about Conserving Outdoor Sculpture where they in-depth seriously devote an entire chapter on the chemical formulation of paints, patinas and coatings.

I am the Technical Partner for O'Michael Studios, Inc. <omichael.com>

Yesterday I did pick up a can of the duplicolor touch up laquer. so far it dried great.

Joe

Glad it's working!

I have learned through "life experience-trial and error" and then confirmed by The Getty Center, (yes that Getty Museum) paint and coatings (yes again they are not semantic equivalents) can be real tricky things with a large material, chemical and environmental multi-variant matrix of effectors. I have sorrily learned some of the effectors can only be classified as 21stC absurd.

I have had mixed results with Rustoleum brand rattle cans. Sometimes very slow to dry, sometimes poor adhesion, sometimes a defective can of paint and other times a bad finish. Still, I've also had good results too - sometimes very good results.

What I did notice is that Krylon rattle can paint seems to be more "usable", in the sense that I don't have the same issues I have with Rustoleum. I've painted cheap extension cords with Krylon paint and had success. Ditto for the $0.99 Home Depot rattle can paint. I haven't tried Rustoleum, but I won't knowing that you've had problems.

I will give Rustoleum kudos for making a paint that does great on metal, particularly steel or iron. The stuff does a great job protecting metal - much better than Krylon and the cheap stuff.

As a sidenote, here in So Cal, Home Depot sells quarts and gallons of oil based Rustoleum paint. I believe it's mostly, if not all glossy paint. I've found a fantastic use for the paint. I have some very "rough" tenants, who are also sometimes messy. I paint the door trim, baseboards and the kitchen cabinets/pantry with the oil based Rustoleum paint. It's amazing for protecting the wood and cleans up so well. A little touch up and we're back in business! It's also very forgiving and if I don't do a 100% perfect job cleaning up the dirt in the kitchen, the paint still adheres well and the film will cover any dirt - I think the oil based paint may mix with the oil and grease residue and forms a nice paint film.

Good luck with your project.

Bruce Frank said:

"There are inexpensive dip-tube spray systems that use throwaway containers."

I have used Preval - Refillable spray system - Spray any paint! with much success. The only problem is, if you buy a quart can of Rest. and want to use them, you will have to thin it with something. You MAY be able to combine the dryer with this concoction and make it work.

I'm out of ideas. Good luck!

I love the Preval sprayer. It does a great job touching up spots - like drywall repairs from my tenants!

I'm wondering if the OP's problem is with the paint, not the delivery system. Wondering if the Rustoleum in a quart can will do the same thing as the rattle can?

My only expertise in painting is practical. I remember a little bit about the chemistry, but I am by no means someone who is knowledgable about it.