Why is My Spray Paint Going On with a "Grainy, Sandy" Texture?

[brockrwood]

See pictures. The spray paint is going on with a "sandy" sort of texture instead of nice and smooth. I put the can of spray paint in hot water for about 5 minutes before I started painting.

I am using Rust-Oleum American Accents 2X "gloss" "key lime".

Wind speed is 10 MPH with gusts to 18 MPH.

Painting outside. Trying to spray between gusts of wind.

Humidity is low (21 percent).

Temperature is about 65 degrees fahrenheit.

 

[dvdsnyd]

First coat?
Spraying over primer?

 

[Banzai88]

Lesson learned: Test spray before using on your project.

That said, looks like either bad paint, bad spray head, or spraying too far from the project.

 

[neil_w]

or spraying too far from the project.

Yes, especially on a windy day. I’ve given up trying to paint when it’s windy.

 

[brockrwood]

First coat?
Spraying over primer?

Yes. First coat. Spraying over primer.

 

[brockrwood]

Lesson learned: Test spray before using on your project.

That said, looks like either bad paint, bad spray head, or spraying too far from the project.

I thought about the "not close enough to the rocket when spraying" issue. I tried spraying about 2 inches from the rocket. Still came out that way.

Could be bad paint. I tell you, the rattle cans are inconsistent from can to can. I have to admit that my best results are from using good, old, cheap, Rust-Oleum enamel. Not the "2X" stuff, just good, old enamel.

Sigh. Oh well. Still looks OK from 10 feet away.

 

[brockrwood]

Yes, especially on a windy day. I’ve given up trying to paint when it’s windy.

It's probably the wind. Still, I think I have painted in breezy conditions like this before and the paint went on OK. Sigh.

 

[neil_w]

It's probably the wind. Still, I think I have painted in breezy conditions like this before and the paint went on OK. Sigh.

Maybe. Can't rule out the possibility of a bad can, although it's hard for me to picture spraying from 2" away.

Also, I would think that could be sanded down to look real nice, although you might still need another coat on top of it.

 

[brockrwood]

Maybe. Can't rule out the possibility of a bad can, although it's hard for me to picture spraying from 2" away.

Also, I would think that could be sanded down to look real nice, although you might still need another coat on top of it.

OK, 2 inches is probably a low estimate. Maybe 3 to 4 inches? Basically, I tried to spray as close as I could without whacking the rocket with the can!

Yes, I could sand it down and try again. I kind of want this puppy to be finished, though. Gosh, that sounds bad, doesn't it? What self-respecting aerospace modeler says, "ah, heck, I am going to just live with this second-rate paint job and be done with it"?

 

[bobbyg23]

It's probably the wind. Still, I think I have painted in breezy conditions like this before and the paint went on OK. Sigh.

Nah, not the wind. Just a bad can. I painted last night in the wind and it went on just fine.

 

[neil_w]

What self-respecting aerospace modeler says, "ah, heck, I am going to just live with this second-rate paint job and be done with it"?

Um, me on almost every build?

[edit: never mind, I missed where you said "self-respecting]

 

[teepot]

I have had more than a few cans of Rusto 2x do that. And I have had it come out like water. The regular Rusto not so much. I bought about 15 cans of Krylon and am going to use that for the next few rockets. I hope I get better results. It seems that the Rust-oleum quality has gone down hill in the last 9 months. I have had more problems in that time than in the previous 2 years.

 

[manixFan]

Hmm, only 20% humidity? I've had a problem when painting in low humidity where the paint 'flash dries' before it hits the surface of the object being painted and gets very grainy. But usually smaller grain, almost like fine sand. And if you are holding the can close to the surface, you should still be fine when it hits your rocket.

A simple test to see if it's the paint is to spray a piece of plain cardboard in your garage or other protected area. It just needs to be a small section. If it looks ok you know the paint is probably fine and it's the primer or another prep issue, or the atmospheric conditions of where you were painting.

Whenever I'm trying out a new primer/paint combo, I always try it on cardboard first, or some other scrap material. I learned that the hard way, like most everyone else it seems.


Tony

 

[Wally Ferrer]

Maybe not a do over, you could try a light wet sand with 800 or 1000+ grit to knock the knobs off and see how it looks. Bad results worst case you can hit it with another light coat of bumpy paint...

 

[DaHabes]

I had this happen on a recent paint job as well, conditions no different than past paint jobs. I attacked it by damp (wet) sanding off the bumps with 400 grit then doing another light coat. Did a final damp sanding with 600 grit and it looked as good as any other of my paint jobs (aka, it'll fly).

 

[Back_at_it]

I've seen this in windy conditions or when spraying over bare tubes. Wait about 3 days and do a light sanding with 400 grit sandpaper. Wipe down with alcohol then put on a second coat. Don't get in a hurry. This is crap Rust-Oleum paint. Wait at least three days before you attempt to do anything with it. If you try to recoat it before then it will just crack and peel.

 

[icyclops]

See pictures. The spray paint is going on with a "sandy" sort of texture instead of nice and smooth. I put the can of spray paint in hot water for about 5 minutes before I started painting.

I am using Rust-Oleum American Accents 2X "gloss" "key lime".

Wind speed is 10 MPH with gusts to 18 MPH.

Painting outside. Trying to spray between gusts of wind.

Humidity is low (21 percent).

Temperature is about 65 degrees fahrenheit.

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I never use a paint that is both paint and primer together. I cannot tell from the picture if this is acrylic or enamel…it makes a difference. In my opinion any paint that tries to do both is like a jack of all trades and a master of none….

 

[brockrwood]

I never use a paint that is both paint and primer together. I cannot tell from the picture if this is acrylic or enamel…it makes a difference. In my opinion any paint that tries to do both is like a jack of all trades and a master of none….

I am not sure what the Rust-Oleum “2X Ultra Cover” is. Could be acrylic. I have to agree that going simpler is usually better, even if it takes three more days to get all of the coats on. I particularly wanted these two colors, “key lime” and “meadow green” so I could do a “lemon lime” vibe paint job. The regular Rust-Oleum enamel, at least where I live, does not come in such a wide variety of colors.
I am beginning to think that the windy conditions are what caused my problem. When I put the second coat of paint on, in less windy conditions, the same kind of paint seemed to go on just fine. .

 

[neil_w]

I am not sure what the Rust-Oleum “2X Ultra Cover” is. Could be acrylic.

It's enamel.

 

[brockrwood]

It's enamel.

I think the wind was my problem. An 18 mph wind will definitely interfere with the spray from a rattle can. I have to learn to be patient and wait for a day when the wind is nice and calm. I used to have a "car port" sort of structure attached to my garage that I could use to paint in, even on windy days. It was built by the last guy who owned my house. It was not built very sturdily. Last winter the weight of the snow on the car port collapsed the car port onto itself. It has now been scraped and hauled away and all I am left with is a concrete slab. Sigh.

 

[Charles_McG]

I have the occasional can of Rusto 2X do this to me. Sanding and repeating is the only recovery. It's definitely the occasional can. It's -usually- but not always more when it's full or the propellent pressure is high.

My pet theory is that cans that do this have a failure of the mechanism that allows them to be used upside-down such that propellent mixes with the paint during the spray.

I've successfully used the remainder of problem cans by spraying with the can upside down.

 

[brockrwood]

I have the occasional can of Rusto 2X do this to me. Sanding and repeating is the only recovery. It's definitely the occasional can. It's -usually- but not always more when it's full or the propellent pressure is high.

My pet theory is that cans that do this have a failure of the mechanism that allows them to be used upside-down such that propellent mixes with the paint during the spray.

I've successfully used the remainder of problem cans by spraying with the can upside down.

Neat idea! I will try it!

 

[Charles_McG]

Try it on something disposable first!

 

[brockrwood]

Try it on something disposable first!

Well said!

Here she is. Not too bad, even with slightly grainy texture on the paint job. Can’t tell she has a slightky inferior paint job if you are standing a safe distance from the launch pad. ;-)





What name shall I give to this homemade aeronautical craft?


Silly iphone makes pics come out sideways.

 

[Charles_McG]

When you upload from an iphone, select full size. The forum will downscale it server-side. The iphone downscale routine rotates it.

 

[teepot]

Call it 7 up or Sprite.

 

[messedupryan]

Temperature is about 65 degrees fahrenheit.

I've had similar issues when the temp is below 70. I ran into this in the past few weeks trying to rush to get paint on some LPR builds I am working on. All 3 colors of paint did this to me. I paint in the open, so there is always a slight breeze, but I would say it was rather calm this night.

 

[neil_w]

Nice Purple Nova. What’s it look like in finished form?

 

[messedupryan]

Still a work in progress. I am planning to fly it next weekend at a club launch with my daughter. I have the rest of this week off and a primary goal is to finish the trio of rockets I am working on! I'll also be updating the build thread with lots of photos.

 

[brockrwood]

I've had similar issues when the temp is below 70. I ran into this in the past few weeks trying to rush to get paint on some LPR builds I am working on. All 3 colors of paint did this to me. I paint in the open, so there is always a slight breeze, but I would say it was rather calm this night.

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Dang. We need a heated “painting shed”.