Rust-Oleum appears very soft

[yayeric]

I've been working on painting the trailer frame and I don't think it's going well.

Here was my process;
1. Thoroughly and completely strip the metal surface bare, removing all rust, paint, mil scale, everything
2. Thoroughly sand all surface with 60 grit sand paper, even the crooks and crannies
3. Spray the metal with acetone, wipe the surface. Repeat until every surface produces a clean paper towel with no hint
4. Spray on 2 coats of Rust-Oleum Primer
5. Allow the Primer to sit for 24 hours before applying paint (per instructions)
6. Using Rust-Oleum 'Professional Grade' Oil-Based Enamel, I mixed with a drill-bit mixer, I rolled on a coat. It was on the thick side.
7. Wait 48 hours (as per instructions), checked the coat. The primer looked dry but I was still able to press my finger nail into it. It felt similar to a slightly stiffer than normal piece of cork from a wine bottle. The instructions stated wait 48 hours between coats, so I applied the second coat.
8. Same as 7.
9. Wait

It has been 4 days since I applied the third coat. The Rust-Oleum enamel is still soft, it does not appear to have gotten harder. For some environmental context, I live in a desert and the humidity is essentially 0%. The frame is also in a temperature controlled environment, around 70°C. This is within the manufacturers recommendations (unless I'm mistaken...). I also did not use a hardener, because I didn't know they existed and there is no mention of that in the instructions.

At 96 hours, I feel like this should be complete. This is costing me extra money to store my trailer frame that is getting hard to afford so this is beginning to stress me out. I also have to dance around the trailer like I'm dodging lasers to access my rented space, and so far I have managed to damage it twice on day three after the third coat. I piece of wood hit the frame and scraped the paint to the primer or the metal (I can't tell which).

I don't understand exactly what it is I'm waiting for. This product has been pretty well reviewed here, but from what I'm seeing I feel like 1 mile on a dirt road is going to make the Rust-Oleum enamel appear as if it took a 30 foot hit from a shotgun. The fender coating won't be able to handle any road with a any loose material. There's absolutely no way I could put the trailer on the frame without scraping off the enamel, even with a roller to prevent scraping. I feel confident I could scratch it off with my nails if I really tried, even 4 days of curing.

Is this normal? Other sources online say to wait waits to months for it to fully cure. I don't have that luxury. I'd also prefer not to spend the time and money to reclean the metal for another product, but I will if I have to. Feeling lost here

 

[Tony Latham]

Is this normal?

I've never had that problem with Rust-Oleum, but I use a different primer.

I suggest putting it in the sun. There's something about UV light that kicks paint and varnish off.

Keep us posted.

Tony

 

[yayeric]

I can't put it in the sun - it's too cold outside and there's no where it wouldn't get stolen.

I called the company today. Apparently it requires 7-10 days to 'fully' cure. It really pisses me off that information was not on the instructions. "Fully Dry within 24 Hours" it says, then nothing. No information on "Curing Time".

Just checked the paint, it's still soft. It's also received minor damage, meaning I have to wait for it to 'fully' cure, sand it, repaint that section, then wait another 10 days hoping it doesn't get damaged before I can put on the final coat of bed liner. Pretty confident that the thick coat I put on is to blame for this.

I can either wait for it to cure, some unknown amount of time, hope it doesn't get damaged again, or I can sand it all off and restart with a product that has a reasonable drying time.

I feel like I'm just going to grind all that off and restart. I really don't like just sitting here waiting and throwing away money. I just feel like I'm wasting my time.

 

[Tom&Shelly]

Maybe try a heat lamp? I used that trick to cure epoxy in our (then) unheated garage.

Tom

 

[S. Heisley]

"I feel like I'm just going to grind all that off and restart. I really don't like just sitting here waiting and throwing away money. I just feel like I'm wasting my time."

Before you grind it off, try a hair dryer on a section and see if that helps. It might be a trade-off to grinding it, but if it works, it could save you some money! So, there are two other ideas: the hair dryer and Tom's (above) heat lamp.

If comes to the last resort of grinding, maybe take a metal spatula and scrape as much off as you can, then grind the rest.

Whatever you do, Best Wishes to you.

 

[yayeric]

I have a heatlamp but no platform to mount it. I'll have to see if it's something I can let sit overnight, the fire marshal here is pretty strict. I did plug in an industrial fan to circulate the air to remove any possible vaporization barriers.

I took a breather and took a closer look tonight. Every portion of the Rust-Oleum is still soft but there is a slightly noticeable difference in how easy it is to imprint my fingernail in area. I tried sanding and most of the trailer appears to be able to sand even though it's soft. Some areas are still extremely soft, it won't take a sanding, it looks 'shiny' after a sanding rather than dusty. We'll see what the fan does overnight. Without a fanless trailer to compare it to I won't really know if it's helping but it can't hurt.

Pretty sure this is my fault from a thick layer I put on. I still had my paint roller bin-thing, had some paint in the that was pretty thin and I wasn't able to imprint my nail in that. I guess I have more to learn, I just don't know what I'm doing. The paint roller left quite a bit of paint on trailer when I applied it. We'll see tomorrow. It does appear to be slowly curing.

 

[Tony Latham]

I guess I have more to learn, I just don't know what I'm doing.

Hey, we're all in that boat.

Tony

 

[Tom&Shelly]

I don't know what I'm doing most of the time. When it comes to craftsmanship, based on your posts and pictures, I think you don't know what you're doing at a much higher level than me!

Tom

 

[S. Heisley]

As you can see from the comments above, the people on this website are some of the best people you will ever meet.

 

[Pmullen503]

The hardness of the paint isn't as important as how well it is adhered to the substrate.

I would do a scratch test. The paint is there to protect the metal, if it can't be scratched or knocked off easily, that's probably good enough.

 

[Rich796]

Oil based enamel is notoriously slow drying/curing. Something on the order of 30 days or so. To fully cure, if you did not use a catalyst with it. Even with a catalyst, fully cured is 5 to 7 days, iirc.

For the majority of " automotive type " paint products to function correctly. A minimum of 60° should be maintained to dry/cure properly. ( the temperature of the paint, the item, and the ambient conditions need to meet this minimum ) The lower the ambient temperature, the longer it will take.

Ambient temperatures that are too low. Can actually cause some paint products, to never fully cure properly. Even when brought up to correct temperatures later.

Excessively thick paint film builds. Can also lead to much longer dry/cure times. Especially if proper ambient temperatures are not maintained. And, airflow is at a minimum or stagnant. Like painting in a enclosed garage.

Any kind of sanding/scratch test. Wont really relay any useful durability information. Unless the paint is actually fully dry/cured. If the paint is glossing back up when you sand it. It is still " wet ", uncured.

The suggestions of using heat lamps, warmer air flow, or getting some natural UV radiation on it. Are all excellent.

 

[Tony Latham]

Oil based enamel is notoriously slow drying/curing.

Have you used Rustoleum? Or did you pull this from the Internet?

Tony

 

[Pmullen503]

I painted my most recent trailer (fiberglass over wood) with 2 coats of Rustoleum primer + 2 coats Rustoleum enamel topcoat (24 hrs between coats). There was about a week between the primer coats and top coats. The primer was dry sanded with 240 grit on a DA sander and even after a week, I had minor clogging of the sandpaper.

The color coats took a couple days to harden up enough to do final assembly. There was still a faint whiff of solvent for a few more days so almost a week. Probably some additional curing going on after that.

I think the OP just needs enough time. "Dry" and fully cured are probably not the same.

 

[Rich796]

" Or did you pull this from the Internet? "

I pulled this from my general purpose knowledge. Of a couple decades. Working as a professionally trained, and certified PPG Automotive refinisher/painter.

Is there a slower, commonly used, paint system, than oil based enamel. That I'm not aware of. That you seem to be taking offense to ?

" Have you used Rustoleum? " I'm sure i have, its in just about every big box store there is. Have I used the exact product that the OP has. No, I would have chosen an alklyd enamel based paint system at the very least.

If you'll note. My post was not specifically about rustoleum branded products.

 

[Rich796]

I painted my most recent trailer (fiberglass over wood) with 2 coats of Rustoleum primer + 2 coats Rustoleum enamel topcoat (24 hrs between coats). There was about a week between the primer coats and top coats. The primer was dry sanded with 240 grit on a DA sander and even after a week, I had minor clogging of the sandpaper.

The color coats took a couple days to harden up enough to do final assembly. There was still a faint whiff of solvent for a few more days so almost a week. Probably some additional curing going on after that.

I think the OP just needs enough time. "Dry" and fully cured are probably not the same.

Generally speaking. Dry times will refer to solvent/reducer loss. Cure times, will refer to crosslinking or self polymerization of the base resin.

 

[Tony Latham]

If you'll note. My post was not specifically about rustoleum branded products.

I apologize. Frequently, we get first-time posters on here that are bots.

Tony

 

[S. Heisley]

May I suggest you call the paint manufacturer? Sometimes, they will have a solution that none of us thought of. If they do, please post it here? Thanks.