Weeds, after I sand blast any metal parts I use Prep- step made by Zero-Rust. Prep-step is a powder that you mix 2 table spoons of into 1 gallon of water and using a sprayer of any kind you just spray the bare metal real good. You can leave the parts outside and they will not rust after this is done. Prep-step does not need to be cleaned off before painting, it helps in paint adhearing to metal and is also great in treating rusted metal before painting. By using this you would not have to be in a hurry to primer your metal. I hope this helps you a little.
Jamo