What DON'T I know about paint?

SixPapaCharlie

SixPapaCharlie

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I don't know how to professionally paint but I know how to amateur paint. I painted a pinewood derby car in cub scouts and once I read on the internet that you can mix rustoleum 50/50 with mineral spirits and use a fine roller to paint a car. I take risks so I painted this thing front to back in the most ghetto way possible for about $200:

10944874_10205989257477451_6365745294490703259_o.jpg


I sprayed the stripes, rattle canned the clear and it was not amazing but it was really good looking. Point is I painted some sht once.




So today I am painting a part I bought for an airplane (Unless that isn't allowed, then it was a pinewood derby car for my kid)
I prime it, I thin out some enamal and airbrush the pinewood derby car and it looks great.

Then I go over it with clear (Krylon rattle can) and within a minute it looks like I poured acetone on it. All the paint bubbles, and peels off.
I grab a random piece of plastic from plastic storage and spray rattle can krylon paint on it, let it dry. Then I get a different can of krylon clear, spray it on and boon, bubbles and peels.

Last test, I spray a piece of plastic, let it dry and then SPRAY A SECOND COAT OF THE SAME PAINT. Bubbles and peels.

Has something in paint changed or am I missing something obvious. Why would adding a 2nd coat remove the first coat.

I have tried adding the 2nd coat after about 2 hours and I have tried after about 2 days. same result. the second round of spraying destroys the original.



Also, I sold that Mustang to pay for flying lessons.
I want that car back.
 
I'm also a paint amateur but I've painted a thing or two...

My guess is the clear is using some incompatible chemicals, can you get a clear from the same source/brand as the stuff you're using as a base? It's usually best to stay within the same manufacturer/product line when layering paints- sometimes this kind of thing happens. Maybe someone else will be along to explain the chemistry of it.
 
I paint a fair bit of railings usually delfleet or some ppg flavor.

Have run into this with rattle can's on smaller jobs when I either get in a hurry or get pulled away. A heavy second or topcoat will wreak havoc on base coats that are anything but full cure. On the can it might say recoat within 1 hours or after 3 days. I honestly have never used a clear in a rattle can. I can't even remember the last time I've used a two stage paint.

Reading the paint docs, that krylon clear is 25-50% acetone. So perhaps that's why it looks like you poured acetone on it. Generally using different brands is a no no.
 
Paint dries quickly, but doesn't totally cure for several days.

In between, the solvents in the fresh coat will soften the base coat, turning it into a crinkly, gooey mess.

A few light coats, sprayed just a few minutes apart works best.

I usually spray about four coats, last one about 15-20 minutes after starting.

The last coat is the only one that needs an even, glossy finish.
 
Look at the redcoat and application windows for both the clear and the color. You either need to spray the clear in a very narrow time window or you need to do some prep to the color after letting it dry for a much longer period of time.
 
Clear is available in both enamel and lacquer. I'm guessing you used enamel on the Mustang so it was OK. The Krylon was lacquer so it messed up the enamel color coat.
 
kmacht said:
Look at the redcoat and application windows for both the clear and the color. You either need to spray the clear in a very narrow time window or you need to do some prep to the color after letting it dry for a much longer period of time.
Click to expand...

You know what, you bring up a really good point about prepping me under layer.

Between every layer on the mustang I wet sanded the hell out of it. For this, I'm just spraying one coat on top of another coat but I'm going to go look at the timing window you mentioned as well
 
I bought a '70 Chevy truck one time. The body was in good shape but the previous owner painted it black with a roller.

Instead of repainting it I just put a BUILT 427 in it.

No one laughed after that...
 
You can't paint lacquer over enamal. It will bubble the enamal.

Best is to use the same type of paint from start to finish. For non-catalyzed paints, you want them to dry thoroughly before recoating.

Catalyzed paints have specific time frames for recoating. If you go too long, you need to wet sand to provide grip for the next coat.
 
Pinecone said:
You can't paint lacquer over enamal. It will bubble the enamal.

Best is to use the same type of paint from start to finish. For non-catalyzed paints, you want them to dry thoroughly before recoating.

Catalyzed paints have specific time frames for recoating. If you go too long, you need to wet sand to provide grip for the next coat.
Click to expand...

So the odd thing is this can does not indicate if it is enamel, laquer, etc. It's simply gloss clear.
https://imgs.michaels.com/MAM/asset...40BFDCA59/10722230_1.jpg?fit=inside|1280:1280



Perhaps, I should get one that explicitly says Enamel:
www.zoro.com

Rust-Oleum 12 oz. Clear Gloss Acrylic Enamel Auto Body Paint/Primer 271913 | Zoro

Order Rust-Oleum 12 oz. Clear Gloss Acrylic Enamel Auto Body Paint/Primer, 271913 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.
www.zoro.com www.zoro.com
 
Zeldman said:
I bought a '70 Chevy truck one time. The body was in good shape but the previous owner painted it black with a roller.

Instead of repainting it I just put a BUILT 427 in it.

No one laughed after that...
Click to expand...
Giggled while they rode in it?
 
Had to repaint the hood on my '08 F-150 due to corrosion under the factory paint. I did it with the $20 Harbor Freight HVLP spray gun. Primer, Base, and Clear Coat. Came out WAAAY better than the factory orange peel did, lol.

1705082212784.png
 
Zeldman said:
I bought a '70 Chevy truck one time. The body was in good shape but the previous owner painted it black with a roller.

Instead of repainting it I just put a BUILT 427 in it.

No one laughed after that...
Click to expand...
I bought a red rusty 72 challenger one time with a broken engine for 100 bucks back around 1979-80.
I put a hot 340 in it and had a lot fun with that car. It was reliable and fast for what it was. I drove it for few years until it got too rusty and I took it off the road and saved the engine for another car. I bought cutting torch for at home and cut that rusty challenger up in about 8-10 pieces and put a piece out in the trash at the end of the driveway each week. I got rid of the whole car that way. That was before I heard of scrap yards.
Couple people probably laughed but didn't after they saw it run.

That is one nice looking mustang!!!

I have never had any luck with rattle can paint.
 
SixPapaCharlie said:
So the odd thing is this can does not indicate if it is enamel, laquer, etc. It's simply gloss clear.
https://imgs.michaels.com/MAM/asset...40BFDCA59/10722230_1.jpg?fit=inside|1280:1280



Perhaps, I should get one that explicitly says Enamel:
www.zoro.com

Rust-Oleum 12 oz. Clear Gloss Acrylic Enamel Auto Body Paint/Primer 271913 | Zoro

Order Rust-Oleum 12 oz. Clear Gloss Acrylic Enamel Auto Body Paint/Primer, 271913 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.
www.zoro.com www.zoro.com
Click to expand...

I think the Painter's Touch is enamel, but it's got a lot of solvent in it. When shooting clear, I would wait until the color is fully cured.

Here's their instructions:
Dry & Recoat Times based on 70°F – 50% relative humidity. Allow more time at cooler temperatures. Dries to the touch in 20 minutes, to handle in 1 hour and fully dry in 24 hours. Apply a second coat or Clear coat within 1 hour or after 48 hours. Apply clear in 2-3 light coats a few minutes apart. NOTE: On plastic maximum paint adhesion and durability is achieved in 5-7 days.
Click to expand...
 
SoonerAviator said:
Had to repaint the hood on my '08 F-150 due to corrosion under the factory paint. I did it with the $20 Harbor Freight HVLP spray gun. Primer, Base, and Clear Coat. Came out WAAAY better than the factory orange peel did, lol.

View attachment 124295
Click to expand...
That's not surprising.

When I was in the Big 3 doing this, we were severely limited by EPA air permit to a certain low number of tons/year of VOCs per exhaust stack.

The only paints we could use flowed like crap and orange peel was a given. Small shops didn't have the same restrictions, or ignored them.
 
ElPaso Pilot said:
That's not surprising.

When I was in the Big 3 doing this, we were severely limited by EPA air permit to a certain low number of tons/year of VOCs per exhaust stack.

The only paints we could use flowed like crap and orange peel was a given. Small shops didn't have the same restrictions, or ignored them.
Click to expand...
I never would have attempted painting the hood if the truck were any other color than gloss black lol. I wouldn't have wanted to try and figure out tinting and blending the color to match 12yr old paint. It was easier just to remove the hood and sand it all down to bare metal, treat the corrosion, then do the layup. Luckily my drop cloth garage paint booth wasn't subject to any VOC limitations lol.
 
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