Most likely, your paint is incompatible with the surface below. The paint and whatever surface treatment was originally applied to the knob, are chemically reacting to each other.

I think that by removing the first coat, you also might have removed some of the original coating underneath, which would account for less of a reaction the second time around.

In order to paint, you might have to remove the original protective coating entirely, so you can start on a non-reactive surface. Good luck.

PS:

As a teenager, I painted one of those "architect" lamps my parents had. Black paint on white finish. All looked fine, until a couple of hours later, when my paint had turned into a perfect crackle finish. NOT an effect I had wished to achieve.

Both my black matte paint and the white finish underneath rubbed easily off together and the steel underneath appeared. I thoroughly cleaned it up and repainted without problems.

Hand oils destroy paint. Or paint adhesion. Painted knobs simply do not hold up to anything but the most minimal of use.

If you want a more permanent solution, that would be having them powder coated. But you can buy all new by the time you remove everything and take them in for media blasting and coating.

I have to agree. I was in a house a few days ago, that the door knobs had obviously been sprayed a nickel color finish, and there were big brass patches all over. Looked worse than if they had been left alone. Better to just replace them. Interior door assemblies are not all that expensive.

It's called a pinterest fail.

We are spending much on our home renovation but more than the $ of replacing, I am a recycler so just trying to lessen the burden on the earth. Perhaps I will only paint the lesser used knobs. Still would appreciate constructive advice on a clear coat if anyone has had any luck with them on a similar project.

I would peel or scrub the paint off. Then instead of changing the color with paint, do it with RubNBuff which is a wax. Then seal the wax with polyurethane (but only if needed). Once you buff the RubNBuff it might be that no sealer is needed.

This might not be a forever fix but it will look a lot nicer then painted knobs. It will also be cheap and fast because you wont have to wait for paint to dry. Touchups can be made as needed without removing the knobs.

http://www.ourfifthhouse.com/2015/10/16/rub-n-buff-to-rescue/

I don’t have clear coat advice, but here in NE there are many places that will take doorknobs and resell. So another option to avoid land fill.

Tacky? Double entendre? Yes, definitely tacky. Nothing will hold up to hands using painted knobs. Especially ones not properly prepped to begin with. You're wasting money and effort. And making everything look peeling, shabby, cheap, and tacky in the mean time.

That sprayed and peeling paint is far more damaging to the environment than replacing them and recycling the old ones for scrap metal.

Do you have a ReStore near you? Habitat for humanity’s store? The one near me always has tons of doorknobs in all different finishes. And you can donate yours if you decide to go the route of buying new ones.

Op, I did what you did on some bathroom door/drawer pull. I soak them to get clear coating off the brass, sanded every nook and cranny so would get good adhesion. Sprayed a couple (2-3) of very thin coats, drying for a couple of days in between. Applied clear coat, oh I also did a primer for metal I wanted this to last. I was also wanting to do to kitchen pulls (same ones) . After about 9 months all my careful work started chipping off.

As for tackiness on your drawer pulls. Maybe coating was to thick. Also it cures better/ faster in a warm room with good air circulation. A clear coat won't protect the underlying paint if not fully cured. Maybe a bad batch of paint, or old possibly reasons for it not curing. I don't know what else it could be.

If recycling is the issue, take the doorknobs and have them plated in the color of your choice.

I bought vintage door hardware for my interior doors and had them plated in an oil rubbed bronze finish and they turned out beautifully.

Replating is not cheap. I had some desk drawer pulls replated, it about equaled the cost of replacing with similar quality and didn't have to drill new holes. Cost for 7 was about $110 for satin finish with clear coat. But I started with a ugly desk that was used as a 50 gallon aquarium stand. Was going to get rid of the battered thing, until I opened drawer. Solid cherry by a well known high end furniture maker, it's beauty hid under water stains a finish that did it no favors. Now it's a star with a finish that highlights the cherry wood.

I wasn't trying to save money by having hardware replated. I wanted a specific stye of vintage door hardware and since the rest of my hardware was copper or oil rubbed bronze, the finish needed to be ORB.

I mentioned replatng as an option only because OP wrote that recycling was more or as important as economics.

I can't imagine that paint on any kind of metal surface that is "handled" would ever provide a long term solution.

Actually, the freshly painted knobs look really nice (not tacky in my opinion!) though they are not vintage. I did properly prep the knobs with cleaning and sanding. I did a similar project on an old brass headboard and 2 years later, it still looks great (again, not tacky!). I will look for those places to donate the old knobs. Thank you for those trying to help me with this project.

It sounds like the knobs are brass. Did you use an etching primer? That's what's needed for proper adhesion onto a non-ferrous metals.

Also 24 or 48 hours is not nearly enough time for the paint to fully cure. It can take up to 30 days. I'd wait a couple of weeks at a minimum before putting them back into service.

Etching primer? Ok, would I still need to sand with steel wool prior to application of the etching primer? And Ok, I will cure longer for sure.... Thank you!!!

Steel wool wouldn't hurt. The important thing is to remove any coating so you're down to bare metal before priming and that the surface free of dirt, grime, grease etc. The primer is designed to chemically etch the surface of the metal so it has "tooth" for the primer to adhere too.

You want to remove any finish coat (i.e., clear coat) that is on the surface before using etching primer. It's designed to chemically "bite" into the metal for proper primer adhesion. You also want to make sure that the metal free of any dirt, grease, etc.

Curious how this all turned out. I just discovered this thread. Have used the etching primer, steel wool, about 5 coats of spray. Let it cure for 10 days. All to no avail...It started to rub off (not chip, mind you - so it didn't feel like an adhesion problem per se - just kind of "dissolve off"). Hope this helps someone else save the time...