When you apply urethane enamel over an oil-based primer, it can create adhesion issues due to the differing chemical compositions and drying times. The urethane may not bond properly, leading to peeling, cracking, or bubbling over time. To ensure a successful application, it's recommended to sand the oil-based primer lightly and use a compatible primer if necessary. Always check the manufacturer's guidelines for compatibility to achieve the best results.
It is possibly not on a good primer .
Yes, that was the original intention of urethane.
Yes. But you can't do the reverse. So if your primer is lacquer-based you can spray an over-coat of enamel on the top.
You can use either a water or oil-based paint over a latex primer.
Alkyd Enamel is really old school primer. I personally would sand it with 400 wet/dry and put a coat or two of an epoxy primer over it then you can put just about any type of paint on it. If you don't want to do that, probably your best best would be n Enamel top coat , You can still get Automotive Enamels but they will be expensive because the EPA is really cracking down on the solvent based finishes. Color selection may also be limited but they are out there. And even if you use an enamel , you should clear coat it with a Urethane Clear. IT helps protect the base coat from fading and gives a great gloss when buffed. I have painted a lot of cars with Enamels and they go on fairly heavy so watch out.
Yes, urethane is oil-based. Oil-based urethane typically has a longer drying time and provides a more durable finish compared to water-based urethane. Water-based urethane dries faster, has less odor, and is easier to clean up.
Not directly. You will need to use a primer made to adhere to oil and will accept a latex topcoat.
Urethane primers are not not compatible with gelcoat, nor are epoxy primers. Gelcoat can only be applied to bare fibreglass, existing (well sanded) gelcoat or polyester/vinylester based fillers.
Yes, prime with a 100% acrylic high adhesion primer, then coat with either a water based or oil based enamel paint for durability.
Minwax stains are made to go directly onto wood. You do not need primer, and I think it looks awful over primer.
It will protect the paint as long as you use a water based varnish, never use oil based varnish over water based paint. Tip: "water based enamel= water based finish". "oil based enamel= oil based finish".
Yes, it is always necessary when carrying out repairs . The area surrounding the repair is sanded , and the primer patch extends outside the repair onto this "feathered" area. Both epoxy and urethane based primers are suitable.