Major problem with my road aluminum frame. Went for respray. Oxidization has made it v difficult for new coat to stick. Any ideas about preparations that might help new paint to not react?

Hello, sorry I am no expert but there are special primers that have to be used when spraying aluminium as it will “basically” etch into the metal. Google it I’m sure you will find something. I will have a look also and post anything here if I find it.
Cheers,
Mark

Thanks.

is this powder coating?

You need an acid etch primer. These “eat” into the surface to provide a key. Normal primer, as you have experienced, just comes off.

No it is not, Powder coating is where the paint/powder is positively charged as it goes through the paint gun. The frame is negatively charged and then the two form an actual bond together once the powder is baked onto the frame. This is just a paint that burns itself into the metal, creating a normal surface for the final paint to be put onto.