I have been repainting a vintage Italian race bike. I stripped to bare metal, primed with Rustoleum bare metal primer followed by primer sealer and Rustoleum yellow spray enamel. I was careful to always wear gloves to avoid contamination with body oil . I sanded the yellow top coat with Amazon brand 1500 grit sand paper dry then wiped down with amazon tack cloth before spraying Rustoleum automotive clear which was warmed to blood temp and thouroughly shaken. the paint can was almost new, only being used to spray clear on the fork.

As soon s the clear hit the yellow top coat (which had dried for 3 weeks) it wrinkled the paint. I

I am certain I did everything right and can't figure out what happened. The fork which I did a couple weeks earlier, came out fine.

Anyone have a thought as to what happened?

My thoughts

1 contamination of the sand paper?
2 tack cloth too tacky?
3 problem with the clear paint?

I have painted at least 50 bikes over he years and this has happened a couple times before.
I will sand back the paint and recoat with yellow, then try again with the clear. .

way back it was no lacquer over enamel- would alligator the base color.

not sure the current chemistry but when I was 10 I learned a labor intensive lesson.

Since you are using Rustoleum products on this respray, that is odd that this happened however, I have called the 800 number for Rustoleum (a decade ago) and have gotten good advice that went beyond just the original question that I asked. The rep' was helpful. I don't remember the reason for the phone call, but it might have been similar.

Rustoleum small projects: 1-800-481-4785

Rustoleum Automotive paints: 1-800-585-8430

Let us know what you learn.

Alligator finish should not have happened with Rustoleum over Rustoleum over Rustoleum. I think you have a good case for an RMA and for product replacement.

I use 2k automotive clear coats nowadays. They seem to cover Rustoleum, Duplicolor and other enamels without issues. It seems to have allowed me to sidestep this issue. You don't need a great gun to do this, I have an $150 gun and a Harbor Freight gun. The Harbor Freight gun is good. You also need a compressor, the hose, fittings, regulator and filter. And don't forget the respirator. That is a lot of stuff, if you don't have some of it already it could be more than you want to get into. If you have a small compressor, adding a 5 or 10 gallon air storage tank, can allow you spray for longer while maintaining enough air.

The other way to go is to get Automotive 2k clear in a spray can. It cost a lot more, but it provides a more durable finish.

Eastwood 2k Clear Coat

SprayMax 2x Clear Coat at Summit Racing

You still need a respirator, but you probably already have one.

one would think BUT, the chem families are all over the place now.
while waiting for the workweek, reference the petroleum distillates noted on the labels. if the clear notes ketones and the color can label does not. that is a problem, lacquer over enamel

the age of the cans were not referenced, in California... huge shifts over time

You're clear over the yellow needs to be the kind that has an activator to create a protective barrier. If your clear is just like your yellow except with no pigment (in other words the kind without an activator), it will wrinkle. The solvents in the new layer will dissolve some of the old paint layer and make it wrinkle. This is basic paint knowledge.

For example if I am painting a frame with yellow paint that is not catalyzed, and I put a catalyzed clear over it, all is fine. If while sanding the protective clear to prepare it for a smooth glossy final clear (or most likely 2 coats of clear) and I sand through the clear and scrape the yellow below, I can't just put more yellow on, I have to put some kind of catalyzed paint on first or when I apply the yellow again it will wrinkle the undercoat yellow, This wrinkling does not happen ever time but it will most likely happen unless an activated paint is an in-between protective layer.

Thank you all for the imput on the wrinkling paint.

I contacted Rustoleum about it and here is their reply.
______________________________________________________________________________________________

Hi, John. Thank you for contacting Rust-Oleum Product Support. We appreciate you reaching out to us!
We're sorry to hear about the issues you are experiencing with the Automotive Acrylic Enamel 2X spray paint.
The recoat time on that paint is within 1 hour or after 48 hours.

What you are experiencing is called “wrinkling” and is due to the recoat timing.
Even though you waited what should be long enough for the yellow coat to dry (3 weeks), it evidently hadn't cured all the way through yet, and the solvent in the clear ate through the skin that had formed, causing the wrinkling.

To avoid wrinkling, the best way to apply Rust-Oleum spray paints is to apply two or more light coats a few minutes apart.
This includes any primer, color, and clear coats. In other words, don't wait to recoat or apply the clear coat.

Recoating must be done in under 1 hour or after 48+ hours. The 48 hours are based on 70° F temperatures and 50% relative humidity or less. If it's cooler than 70° or more humid out, you would need to wait longer. If it’s hotter or really dry, then the 1-hour window can shorten by quite a bit.

When recoating after 1 hour or before the 48+ hours, the solvent in the new coat of paint can dissolve the film (skin) that has formed, causing it to wrinkle.

Also, do not sand between coats, as this, too, breaks the film, and the coating can wrinkle if the new coat is applied directly after sanding.
If you do have to sand due to something like a drip or you just want a smoother finish, then we recommend waiting 48 hours after sanding before recoating.

To fix the wrinkling, we recommend waiting for the surface to dry until you can get a dry sand, then sanding the surface just enough to smooth out the wrinkles. Then wait 48 hours for the paint to air out before spraying another light coat of the color paint, followed by 1-2 light coats of the clear, all coats just a few minutes apart. This waiting period allows any paint that hadn't fully cured more time to dry out.

We hope this information has been useful and has addressed your questions.
Please don't hesitate to reach out to us if you have any more questions.

Thank you!
Diana D.
Product Support Representative

The mistake I apparently made was to sand(with 1500 grit) and then spray the clear a few minutes later.

I sanded off the winkled paint this morningwith 1500 grit wet/ dry paper then washed with Dawn dish soap and dried with a new white shop towel. luckily I didn't sand through the color.

I will wait a few days and then spray the clear . Hopefully this time I will get a good finish.

By the way, as soon as it is finished it will be sold. I an pretty certain it is a 1975 Guerciotti based on frame weight, details, and the previous owner of 25 years' statement.
Unfortunately it has none of the trademark Guerciotti pantographing seen on later models so the boss said I couldn't decal it as one.

My guess , after looking at pics of every early "Guerciotti" I could find is that in the early years they probably had frames built by a number of local builders, hence the differences from frame to frame.
Even without the decals, this is a special frame, weighing in at just over 4 lbs. I have a complete nuevo record group for it and mavic wheels with Campi hubs which I will install if anyone expresses interest in buying it at a reasonable price. Otherwise I will probably outfit it with Shimano bits and we will sell it cheap to some lucky sod who will get a much better bike than he realizes.

waiting & light coats is the key.this past high dew point weather meant about 2 months to refinish this cowl with Rustoleum top coat.

this rustoleum line has a bit better quality than the 2x line.